CINXE.COM

Reduced pressure zone device - Wikipedia

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Reduced pressure zone device - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"957653aa-d0e2-4789-8437-c55ca7279192","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Reduced_pressure_zone_device","wgTitle":"Reduced pressure zone device","wgCurRevisionId":1181718267,"wgRevisionId":1181718267,"wgArticleId":4634175,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Articles with short description","Short description is different from Wikidata","Wikipedia articles needing rewrite from June 2016","All articles needing rewrite","Plumbing valves","Backflow"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Reduced_pressure_zone_device","wgRelevantArticleId":4634175,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[], "wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":9000,"wgRelatedArticlesCompat":[],"wgCentralAuthMobileDomain":false,"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q7306333","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false, "wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","mediawiki.page.media","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups", "ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession","wikibase.sidebar.tracking"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&amp;modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&amp;only=styles&amp;skin=vector-2022"> <script async="" src="/w/load.php?lang=en&amp;modules=startup&amp;only=scripts&amp;raw=1&amp;skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&amp;modules=site.styles&amp;only=styles&amp;skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.4"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/5/50/Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg/1200px-Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="675"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/5/50/Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg/800px-Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="450"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/5/50/Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg/640px-Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="360"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Reduced pressure zone device - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/Reduced_pressure_zone_device"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/Reduced_pressure_zone_device"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&amp;feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="//login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Reduced_pressure_zone_device rootpage-Reduced_pressure_zone_device skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page&#039;s font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&amp;utm_medium=sidebar&amp;utm_campaign=C13_en.wikipedia.org&amp;uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&amp;returnto=Reduced+pressure+zone+device" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&amp;returnto=Reduced+pressure+zone+device" title="You&#039;re encouraged to log in; however, it&#039;s not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&amp;utm_medium=sidebar&amp;utm_campaign=C13_en.wikipedia.org&amp;uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&amp;returnto=Reduced+pressure+zone+device" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&amp;returnto=Reduced+pressure+zone+device" title="You&#039;re encouraged to log in; however, it&#039;s not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"><!-- CentralNotice --></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-Description" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Description"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Description</span> </div> </a> <ul id="toc-Description-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Reduced pressure zone device</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="This article exist only in this language. Add the article for other languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-0" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">Add languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> <div class="after-portlet after-portlet-lang"><span class="uls-after-portlet-link"></span><span class="wb-langlinks-add wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q7306333#sitelinks-wikipedia" title="Add interlanguage links" class="wbc-editpage">Add links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Reduced_pressure_zone_device" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:Reduced_pressure_zone_device" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Reduced_pressure_zone_device"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Reduced_pressure_zone_device"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/Reduced_pressure_zone_device" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/Reduced_pressure_zone_device" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;oldid=1181718267" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&amp;page=Reduced_pressure_zone_device&amp;id=1181718267&amp;wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&amp;url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FReduced_pressure_zone_device"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&amp;url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FReduced_pressure_zone_device"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&amp;page=Reduced_pressure_zone_device&amp;action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q7306333" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Backflow prevention device</div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-Cleanup_rewrite plainlinks metadata ambox ambox-content" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Crystal_Clear_app_kedit.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Crystal_Clear_app_kedit.svg/40px-Crystal_Clear_app_kedit.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Crystal_Clear_app_kedit.svg/60px-Crystal_Clear_app_kedit.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Crystal_Clear_app_kedit.svg/80px-Crystal_Clear_app_kedit.svg.png 2x" data-file-width="128" data-file-height="128" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>may need to be rewritten</b> to comply with Wikipedia's <a href="/wiki/Wikipedia:Manual_of_Style" title="Wikipedia:Manual of Style">quality standards</a>.<span class="hide-when-compact"> <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Reduced_pressure_zone_device&amp;action=edit">You can help</a>. The <a href="/wiki/Talk:Reduced_pressure_zone_device" title="Talk:Reduced pressure zone device">talk page</a> may contain suggestions.</span> <span class="date-container"><i>(<span class="date">June 2016</span>)</i></span></div></td></tr></tbody></table> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/50/Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg/220px-Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg" decoding="async" width="220" height="124" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/50/Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg/330px-Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/50/Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg/440px-Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg 2x" data-file-width="1472" data-file-height="828" /></a><figcaption>Reduced pressure zone device connected to a <a href="/wiki/Fire_hydrant" title="Fire hydrant">fire hydrant</a></figcaption></figure> <p>A <b>reduced pressure zone device</b> (<b>RPZD</b>, <b>RPZ</b>, or <b>RPZ</b> valve) is a type of <a href="/wiki/Backflow_prevention_device" title="Backflow prevention device">backflow prevention device</a> used to protect <a href="/wiki/Water" title="Water">water</a> supplies from contamination. RPZDs may also be known as <b>reduced pressure principle</b> (RP), <b>reduced pressure principle backflow prevention devices</b>,<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">&#91;</span>1<span class="cite-bracket">&#93;</span></a></sup><sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">&#91;</span>2<span class="cite-bracket">&#93;</span></a></sup> <b>reduced pressure zone assemblies</b> (RPZA),<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">&#91;</span>3<span class="cite-bracket">&#93;</span></a></sup> or <b>reduced pressure principle assembly</b> (RPPA).<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">&#91;</span>4<span class="cite-bracket">&#93;</span></a></sup> </p> <ul><li>ASSE Standard 1013 - Reduced Pressure Backflow Assembly</li> <li>ASSE Standard 1015 - Double Check Valve Assembly</li> <li>ASSE Standard 1020 - Pressure Vacuum Breaker</li> <li>ASSE Standard 1047 - Reduced Pressure Detector Assembly</li> <li>ASSE Standard 1047 - Reduced Pressure Detector Assembly Type II</li> <li>ASSE Standard 1048 - Double Check Detector Assembly</li> <li>ASSE Standard 1048 - Double Check Detector Assembly Type II</li> <li>ASSE Standard 1056 - Spill Resistant Vacuum Breaker</li></ul> <p>Backflow preventers are categorized into three groupings: Assembly, Device or Method. With the exception of elimination, these are the only ways one can control backflow from taking place. </p><p>The eight named backflow assemblies all have two resilient seated isolation/shut off valves with properly located test ports. These assemblies have the distinct advantage of being in-line serviceable and can be tested &amp; repaired without having to remove an installed assembly. Special accredited courses are given to test &amp; repair backflow assemblies and only certified testers may test backflow assemblies. </p><p>There are approximately fifteen devices related to backflow which cannot be tested, as they do not have isolation valves or test ports and there are no standards (test procedures) set in place to test for any device. This is what sets an assembly apart from a device. An assembly is testable, but a device is not. </p><p>Lastly, an air gap or barometric loop are methods to prevent backflow from taking place. These are also non-testable. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Description">Description</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=edit&amp;section=1" title="Edit section: Description"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A RPZD is considered suitable for significant hazard applications,<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">&#91;</span>note 1<span class="cite-bracket">&#93;</span></a></sup> that is, where the consequence of backflow into the <a href="/wiki/Water_supply" title="Water supply">water supply</a> would cause significant harm, although not for the highest risks, such as human waste.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">&#91;</span>5<span class="cite-bracket">&#93;</span></a></sup> They are considered suitable because they prevent both back pressure and back-siphonage, because of a redundant design (even with two check valves broken the device still provides protection), and because they are testable to verify correct operation. </p><p>RPZDs are often chosen instead of an <a href="/wiki/Air_gap_(plumbing)" title="Air gap (plumbing)">air gap</a> since the head loss across the RPZD is much smaller. </p><p>The device consists of two independent <a href="/wiki/Check_valve" title="Check valve">check valves</a>, plumbed in series, with a pressure monitored chamber between (also known as the zone). The chamber is maintained at a pressure that is lower than the water supply pressure, but high enough to be useful downstream. The reduced pressure is guaranteed by a differential pressure relief valve, which automatically relieves excess pressure in the chamber by discharging to a drain. Four test cocks are installed to allow an inspector to verify proper operation of the valve with a differential pressure meter. Two valves (one before and one after the RPZD) are provided to allow for testing and repair. </p><p>Facilities that require constant water pressure must install two RPZDs in parallel so that one device will be available to supply the facility while the other is tested or repaired. </p><p>Discharge from the relief device is an indication that either of the two check valves is 'passing' (leaking past their shutoff seats) or the relief valve itself is faulty. Some normal water use conditions may cause short episodes of discharge (this is why check one has a minimum passing value of relief +3. It is designed to handle the pressure fluctuations). </p><p>In the case of the upstream check valve passing, the differential pressure (higher supply pressure compared with the lower chamber pressure) causes any flow to occur only in one direction. A buildup of pressure in the chamber in such a case would be relieved to the drain. </p><p>In the case of the downstream check valve passing, the differential pressure <a href="/wiki/Relief_valve" title="Relief valve">relief valve</a> prevents the possibility of the chamber pressure from exceeding the supply pressure. </p><p>It is theoretically possible that, when both valves are faulty, backflow could occur, should the reverse flow rate exceed the capacity of the relief valve. </p><p>Because certain combinations of check valve failure and/or system backpressure cause the relief valve to discharge, the device must be mounted in a location where the drain will not become flooded. </p><p>An example of where backflow would harm the water supply is the use of well washing devices inside underground sewerage pumping stations. At times untreated sewerage may contain a variety of harmful gases that will effectively break down and deteriorate concrete wells, hence well washers are utilised to spray water and wash down contaminated concrete walls of a well. All well washers are installed with RPZ Devices in case a pumping station breaks down, and the sewerage level rises above the well washer, causing backflow down the water supply line. </p><p>A reduced pressure zone device is tested with a device called a differential gauge. This gauge uses hoses attached to the various test cocks of the RPZD and checks to be certain that the check valve springs as well as the relief valve spring are not fouled and are working properly. There is a variety of manufacturers of these gauges, but most utilize either a three-valve or a five-valve design to test the RPZD in different ways. </p><p>In the <a href="/wiki/United_Kingdom" title="United Kingdom">UK</a>,<sup id="cite_ref-Treloar,_Plumbing,_Backflow_7-0" class="reference"><a href="#cite_note-Treloar,_Plumbing,_Backflow-7"><span class="cite-bracket">&#91;</span>6<span class="cite-bracket">&#93;</span></a></sup> Illinois, <a href="/wiki/New_York_(state)" title="New York (state)">New York</a>,<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">&#91;</span>7<span class="cite-bracket">&#93;</span></a></sup> <a href="/wiki/Texas" title="Texas">Texas</a>,<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">&#91;</span>8<span class="cite-bracket">&#93;</span></a></sup> and <a href="/wiki/Missouri" title="Missouri">Missouri</a>(<a rel="nofollow" class="external text" href="https://www.sos.mo.gov/adrules/csr/current/10csr/10c60-11.pdf">RsMO 10c60-11</a>), the RPZD valve must be tested at least every 12 months by an accredited tester. </p><p>In the UK all RPZD Valve Testers have to be WRAS Accredited </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=edit&amp;section=2" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Air_gap_(plumbing)" title="Air gap (plumbing)">Air gap</a></li> <li><a href="/wiki/Atmospheric_vacuum_breaker" title="Atmospheric vacuum breaker">Atmospheric vacuum breaker</a></li> <li><a href="/wiki/Backflow_prevention_device" title="Backflow prevention device">Backflow prevention device</a></li> <li><a href="/wiki/Double_check_valve" title="Double check valve">Double check valve</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=edit&amp;section=3" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-lower-roman"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text">In the UK they are considered suitable for Category 4 'Significant hazard' e.g. antifreeze, but not Category 5 'Serious health risk', e.g. human waste</span> </li> </ol></div></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239543626"><div class="reflist reflist-columns references-column-width" style="column-width: 35em;"> <ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://bannockburn.org/wp-content/uploads/2014/05/PreventionofBackflowMethodsandDevices_000.pdf">"Methods and Devices for the Prevention of Backflow and Back-Siphonage"</a> <span class="cs1-format">(PDF)</span>. <i>Cross-Connection Control Manual</i>. p.&#160;21.</cite><span title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&amp;rft.genre=unknown&amp;rft.jtitle=Cross-Connection+Control+Manual&amp;rft.atitle=Methods+and+Devices+for+the+Prevention+of+Backflow+and+Back-Siphonage&amp;rft.pages=21&amp;rft_id=http%3A%2F%2Fbannockburn.org%2Fwp-content%2Fuploads%2F2014%2F05%2FPreventionofBackflowMethodsandDevices_000.pdf&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AReduced+pressure+zone+device" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://www.wbdg.org/ccb/ARMYCOE/PWTB/pwtb_420_49_16.pdf"><i>Public Works Technical Bulletin 420-49-16: Cross-Connection Control at Army Installations</i></a> <span class="cs1-format">(PDF)</span>. U.S. Army, Corps of Engineers. 16 July 2001. pp.&#160;10, 12<span class="reference-accessdate">. Retrieved <span class="nowrap">23 July</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Public+Works+Technical+Bulletin+420-49-16%3A+Cross-Connection+Control+at+Army+Installations&amp;rft.pages=10%2C+12&amp;rft.pub=U.S.+Army%2C+Corps+of+Engineers&amp;rft.date=2001-07-16&amp;rft_id=https%3A%2F%2Fwww.wbdg.org%2Fccb%2FARMYCOE%2FPWTB%2Fpwtb_420_49_16.pdf&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AReduced+pressure+zone+device" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.miamidade.gov/water/library/guidelines/backflow-prevention-assemblies-approved.pdf">"Miami-Dade Water and Sewer Department Approved Backflow Prevention Assemblies"</a> <span class="cs1-format">(PDF)</span>. Miami-Dade Water and Sewer Department<span class="reference-accessdate">. Retrieved <span class="nowrap">23 July</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=unknown&amp;rft.btitle=Miami-Dade+Water+and+Sewer+Department+Approved+Backflow+Prevention+Assemblies&amp;rft.pub=Miami-Dade+Water+and+Sewer+Department&amp;rft_id=https%3A%2F%2Fwww.miamidade.gov%2Fwater%2Flibrary%2Fguidelines%2Fbackflow-prevention-assemblies-approved.pdf&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AReduced+pressure+zone+device" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="http://www.scdhec.gov/library/cr-000090.pdf"><i>Backflow Prevention Certification Workshop: Information &amp; Materials</i></a> <span class="cs1-format">(PDF)</span>. South Carolina Department of Health and Environmental Control. pp.&#160;7–8<span class="reference-accessdate">. Retrieved <span class="nowrap">23 July</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Backflow+Prevention+Certification+Workshop%3A+Information+%26+Materials&amp;rft.pages=7-8&amp;rft.pub=South+Carolina+Department+of+Health+and+Environmental+Control&amp;rft_id=http%3A%2F%2Fwww.scdhec.gov%2Flibrary%2Fcr-000090.pdf&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AReduced+pressure+zone+device" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1">"Schedule 1". <a rel="nofollow" class="external text" href="http://www.legislation.gov.uk/uksi/1999/1148/contents/made"><i>Water Supply Regulations</i></a>. <a href="/wiki/HMSO" class="mw-redirect" title="HMSO">HMSO</a>.</cite><span title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=bookitem&amp;rft.atitle=Schedule+1&amp;rft.btitle=Water+Supply+Regulations&amp;rft.pub=HMSO&amp;rft_id=http%3A%2F%2Fwww.legislation.gov.uk%2Fuksi%2F1999%2F1148%2Fcontents%2Fmade&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AReduced+pressure+zone+device" class="Z3988"></span></span> </li> <li id="cite_note-Treloar,_Plumbing,_Backflow-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-Treloar,_Plumbing,_Backflow_7-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="Treloar,_Plumbing" class="citation book cs1">Treloar, R.D. (2006). "Backflow Prevention". <i>Plumbing</i> (3rd&#160;ed.). Blackwell. p.&#160;86. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a>&#160;<a href="/wiki/Special:BookSources/978-1-4051-3962-5" title="Special:BookSources/978-1-4051-3962-5"><bdi>978-1-4051-3962-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=bookitem&amp;rft.atitle=Backflow+Prevention&amp;rft.btitle=Plumbing&amp;rft.pages=86&amp;rft.edition=3rd&amp;rft.pub=Blackwell&amp;rft.date=2006&amp;rft.isbn=978-1-4051-3962-5&amp;rft.aulast=Treloar&amp;rft.aufirst=R.D.&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AReduced+pressure+zone+device" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.health.state.ny.us/nysdoh/phforum/nycrr10.htm">10NYCRR5-1.31</a></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://info.sos.state.tx.us/pls/pub/readtac$ext.ViewTAC?tac_view=5&amp;ti=30&amp;pt=1&amp;ch=344&amp;sch=E&amp;rl=Y">Texas code</a></span> </li> </ol></div> <ul><li>University of Southern California, Foundation of Cross-Connection Control and Hydraulic Research (USC-FCCCHR) Manual of Cross-Connection Control - 10th Edition.</li> <li>International Association of Plumbing and Mechanical Officials (IAPMO) Backflow Prevention Reference Manual - 3rd Edition</li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Reduced_pressure_zone_device&amp;action=edit&amp;section=4" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external free" href="http://www.watts.com/pdf/ES-009.pdf">http://www.watts.com/pdf/ES-009.pdf</a></li> <li><a rel="nofollow" class="external free" href="http://www.kitz.co.jp">http://www.kitz.co.jp</a></li> <li><a rel="nofollow" class="external free" href="https://www.iapmo.org/iapmo/news/IAPMO_pubs_available.pdf">http://www.iapmo.org/iapmo/news/IAPMO_pubs_available.pdf</a></li> <li><a rel="nofollow" class="external free" href="http://www.wrasaccredited.co.uk/WRAS%201.pdf">http://www.wrasaccredited.co.uk/WRAS%201.pdf</a> - UK Guidance on RPZ Valve Installation</li> <li><a rel="nofollow" class="external free" href="http://www.honeywellukwater.com/Products/Backflow-Preventers/BA298F/">http://www.honeywellukwater.com/Products/Backflow-Preventers/BA298F/</a></li> <li><a rel="nofollow" class="external free" href="http://www.honeywellukwater.com/Products/Backflow-Preventers/BA295/">http://www.honeywellukwater.com/Products/Backflow-Preventers/BA295/</a></li> <li><a rel="nofollow" class="external free" href="https://www.sos.mo.gov/adrules/csr/current/10csr/10c60-11.pdf">https://www.sos.mo.gov/adrules/csr/current/10csr/10c60-11.pdf</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Backflow_and_prevention" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Backflow" title="Template:Backflow"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/w/index.php?title=Template_talk:Backflow&amp;action=edit&amp;redlink=1" class="new" title="Template talk:Backflow (page does not exist)"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Backflow" title="Special:EditPage/Template:Backflow"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Backflow_and_prevention" style="font-size:114%;margin:0 4em"><a href="/wiki/Backflow" title="Backflow">Backflow</a> and <a href="/wiki/Backflow_prevention_device" title="Backflow prevention device">prevention</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Backflow prevention methods</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Atmospheric_vacuum_breaker" title="Atmospheric vacuum breaker">Atmospheric vacuum breaker</a></li> <li><a href="/wiki/Air_gap_(plumbing)" title="Air gap (plumbing)">Air gap</a></li> <li><a href="/wiki/Check_valve" title="Check valve">Check valve</a></li> <li><a href="/wiki/Chemigation_valve" title="Chemigation valve">Chemigation valve</a></li> <li><a href="/wiki/Double_check_valve" title="Double check valve">Double check valve</a></li> <li><a href="/wiki/Hydrostatic_loop" title="Hydrostatic loop">Hydrostatic loop</a></li> <li><a href="/wiki/Pressure_vacuum_breaker" title="Pressure vacuum breaker">Pressure vacuum breaker</a></li> <li><a class="mw-selflink selflink">Reduced pressure zone device</a></li> <li><a href="/wiki/Vacuum_breaker" title="Vacuum breaker">Vacuum breaker</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Plumbing" style="vertical-align: middle;;padding:3px"><table class="nowraplinks mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Plumbing" title="Template:Plumbing"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Plumbing" title="Template talk:Plumbing"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Plumbing" title="Special:EditPage/Template:Plumbing"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Plumbing" style="font-size:114%;margin:0 4em"><a href="/wiki/Plumbing" title="Plumbing">Plumbing</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Fundamental<br />concepts</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Air_gap_(plumbing)" title="Air gap (plumbing)">Air gap (plumbing)</a></li> <li><a href="/wiki/Backflow" title="Backflow">Backflow</a></li> <li><a href="/wiki/Compatibility_(chemical)" title="Compatibility (chemical)">Compatibility (chemical)</a></li> <li><a href="/wiki/Corrosion" title="Corrosion">Corrosion</a></li> <li><a href="/wiki/Drain_(plumbing)" title="Drain (plumbing)">Drain (plumbing)</a></li> <li><a href="/wiki/Drinking_water" title="Drinking water">Drinking water</a></li> <li><a href="/wiki/Fuel_gas" title="Fuel gas">Fuel gas</a></li> <li><a href="/wiki/Friction_loss" title="Friction loss">Friction loss</a></li> <li><a href="/wiki/Grade_(slope)" title="Grade (slope)">Grade (slope)</a></li> <li><a href="/wiki/Greywater" title="Greywater">Greywater</a></li> <li><a href="/wiki/Heat_trap" title="Heat trap">Heat trap</a></li> <li><a href="/wiki/Hydrostatic_loop" title="Hydrostatic loop">Hydrostatic loop</a></li> <li><a href="/wiki/Leak" title="Leak">Leak</a></li> <li><a href="/wiki/Neutral_axis" title="Neutral axis">Neutral axis</a></li> <li><a href="/wiki/Onsite_sewage_facility" title="Onsite sewage facility">Onsite sewage facility</a></li> <li><a href="/wiki/Pressure" title="Pressure">Pressure</a></li> <li><a href="/wiki/Sanitary_sewer" title="Sanitary sewer">Sanitary sewer</a></li> <li><a href="/wiki/Sewer_gas" title="Sewer gas">Sewer gas</a></li> <li><a href="/wiki/Sewage" title="Sewage">Sewage</a></li> <li><a href="/wiki/Sewerage" title="Sewerage">Sewerage</a></li> <li><a href="/wiki/Siphon" title="Siphon">Siphon</a></li> <li><a href="/wiki/Storm_sewer" class="mw-redirect" title="Storm sewer">Storm sewer</a></li> <li><a href="/wiki/Stormwater" title="Stormwater">Stormwater</a></li> <li><a href="/wiki/Surface_tension" title="Surface tension">Surface tension</a></li> <li><a href="/wiki/Tap_water" title="Tap water">Tap water</a></li> <li><a href="/wiki/Thermal_expansion" title="Thermal expansion">Thermal expansion</a></li> <li><a href="/wiki/Thermal_insulation" title="Thermal insulation">Thermal insulation</a></li> <li><a href="/wiki/Thermosiphon" title="Thermosiphon">Thermosiphon</a></li> <li><a href="/wiki/Trap_(plumbing)" title="Trap (plumbing)">Trap (plumbing)</a></li> <li><a href="/wiki/Venturi_effect" title="Venturi effect">Venturi effect</a></li> <li><a href="/wiki/Wastewater" title="Wastewater">Wastewater</a></li> <li><a href="/wiki/Water_hammer" title="Water hammer">Water hammer</a></li> <li><a href="/wiki/Water_supply_network" title="Water supply network">Water supply network</a></li> <li><a href="/wiki/Water_table" title="Water table">Water table</a></li> <li><a href="/wiki/Well" title="Well">Well</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Technology</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Brazing" title="Brazing">Brazing</a></li> <li><a href="/wiki/British_Standard_Pipe" title="British Standard Pipe">British Standard Pipe</a> (BSP)</li> <li><a href="/wiki/Cast_iron_pipe" title="Cast iron pipe">Cast iron pipe</a></li> <li><a href="/wiki/Chemical_drain_cleaners" title="Chemical drain cleaners">Chemical drain cleaners</a></li> <li><a href="/wiki/Compression_fitting" title="Compression fitting">Compression fitting</a></li> <li><a href="/wiki/Copper_tubing" title="Copper tubing">Copper tubing</a></li> <li><a href="/wiki/Crimp_(joining)" title="Crimp (joining)">Crimp (joining)</a></li> <li><a href="/wiki/Drain-waste-vent_system" title="Drain-waste-vent system">Drain-waste-vent system</a></li> <li><a href="/wiki/Ductile_iron_pipe" title="Ductile iron pipe">Ductile iron pipe</a></li> <li><a href="/wiki/Flare_fitting" title="Flare fitting">Flare fitting</a></li> <li><a href="/wiki/Garden_hose_thread" class="mw-redirect" title="Garden hose thread">Garden Hose Thread</a> (GHT)</li> <li><a href="/wiki/Gasket" title="Gasket">Gasket</a></li> <li><a href="/wiki/Hydronics" title="Hydronics">Hydronics</a></li> <li><a href="/wiki/Leak_detection" title="Leak detection">Leak detection</a></li> <li><a href="/wiki/National_Pipe_Thread" class="mw-redirect" title="National Pipe Thread">National Pipe Thread</a> (NPT)</li> <li><a href="/wiki/Nominal_Pipe_Size" title="Nominal Pipe Size">Nominal Pipe Size</a> (NPS)</li> <li><a href="/wiki/O-ring" title="O-ring">O-ring</a></li> <li><a href="/wiki/Oakum" title="Oakum">Oakum</a></li> <li><a href="/wiki/Pipe_(fluid_conveyance)" title="Pipe (fluid conveyance)">Pipe (fluid conveyance)</a></li> <li><a href="/wiki/Pipe_dope" title="Pipe dope">Pipe dope</a></li> <li><a href="/wiki/Pipe_support" title="Pipe support">Pipe support</a></li> <li><a href="/wiki/Plastic_pipework" title="Plastic pipework">Plastic pipework</a></li> <li><a href="/wiki/Push-to-pull_compression_fittings" title="Push-to-pull compression fittings">Push-to-pull compression fittings</a></li> <li><a href="/wiki/Putty" title="Putty">Putty</a></li> <li><a href="/wiki/Sealant" title="Sealant">Sealant</a></li> <li><a href="/wiki/Sewage_pumping" title="Sewage pumping">Sewage pumping</a></li> <li><a href="/wiki/Soldering" title="Soldering">Soldering</a></li> <li><a href="/wiki/Solvent_welding" class="mw-redirect" title="Solvent welding">Solvent welding</a></li> <li><a href="/wiki/Swaging" title="Swaging">Swaging</a></li> <li><a href="/wiki/Thread_seal_tape" title="Thread seal tape">Thread seal tape</a></li> <li><a href="/wiki/Threaded_pipe" title="Threaded pipe">Threaded pipe</a></li> <li><a href="/wiki/Tube_bending" title="Tube bending">Tube bending</a></li> <li><a href="/wiki/Water_heat_recycling" title="Water heat recycling">Water heat recycling</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Components</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Atmospheric_vacuum_breaker" title="Atmospheric vacuum breaker">Atmospheric vacuum breaker</a></li> <li><a href="/wiki/Automatic_bleeding_valve" title="Automatic bleeding valve">Automatic bleeding valve</a></li> <li><a href="/wiki/Automatic_faucet" title="Automatic faucet">Automatic faucet</a></li> <li><a href="/wiki/Backflow_prevention_device" title="Backflow prevention device">Backflow prevention device</a></li> <li><a href="/wiki/Ball_valve" title="Ball valve">Ball valve</a></li> <li><a href="/wiki/Bleed_screw" title="Bleed screw">Bleed screw</a></li> <li><a href="/wiki/Booster_pump" title="Booster pump">Booster pump</a></li> <li><a href="/wiki/Butterfly_valve" title="Butterfly valve">Butterfly valve</a></li> <li><a href="/wiki/Check_valve" title="Check valve">Check valve</a></li> <li><a href="/wiki/Chemigation_valve" title="Chemigation valve">Chemigation valve</a></li> <li><a href="/wiki/Chopper_pump" class="mw-redirect" title="Chopper pump">Chopper pump</a></li> <li><a href="/wiki/Circulator_pump" title="Circulator pump">Circulator pump</a></li> <li><a href="/wiki/Cistern" title="Cistern">Cistern</a></li> <li><a href="/wiki/Closet_flange" title="Closet flange">Closet flange</a></li> <li><a href="/wiki/Concentric_reducer" title="Concentric reducer">Concentric reducer</a></li> <li><a href="/wiki/Condensate_pump" title="Condensate pump">Condensate pump</a></li> <li><a href="/wiki/Coupling_(piping)" title="Coupling (piping)">Coupling (piping)</a></li> <li><a href="/wiki/Diaphragm_valve" title="Diaphragm valve">Diaphragm valve</a></li> <li><a href="/wiki/Dielectric_union" class="mw-redirect" title="Dielectric union">Dielectric union</a></li> <li><a href="/wiki/Double_check_valve" title="Double check valve">Double check valve</a></li> <li><a href="/wiki/Eccentric_reducer" title="Eccentric reducer">Eccentric reducer</a></li> <li><a href="/wiki/Expansion_tank" title="Expansion tank">Expansion tank</a></li> <li><a href="/wiki/Faucet_aerator" title="Faucet aerator">Faucet aerator</a></li> <li><a href="/wiki/Float_switch" title="Float switch">Float switch</a></li> <li><a href="/wiki/Float_valve" class="mw-redirect" title="Float valve">Float valve</a></li> <li><a href="/wiki/Floor_drain" title="Floor drain">Floor drain</a></li> <li><a href="/wiki/Flow_limiter" title="Flow limiter">Flow limiter</a></li> <li><a href="/wiki/Flushing_trough" title="Flushing trough">Flushing trough</a></li> <li><a href="/wiki/Flushometer" title="Flushometer">Flushometer</a></li> <li><a href="/wiki/Gate_valve" title="Gate valve">Gate valve</a></li> <li><a href="/wiki/Globe_valve" title="Globe valve">Globe valve</a></li> <li><a href="/wiki/Grease_trap" title="Grease trap">Grease trap</a></li> <li><a href="/wiki/Grinder_pump" title="Grinder pump">Grinder pump</a></li> <li><a href="/wiki/Hose_coupling" title="Hose coupling">Hose coupling</a></li> <li><a href="/wiki/Manifold_(fluid_mechanics)" title="Manifold (fluid mechanics)">Manifold</a></li> <li><a href="/wiki/Needle_valve" title="Needle valve">Needle valve</a></li> <li><a href="/wiki/Nipple_(plumbing)" title="Nipple (plumbing)">Nipple (plumbing)</a></li> <li><a href="/wiki/Pinch_valve" title="Pinch valve">Pinch valve</a></li> <li><a href="/wiki/Piping_and_plumbing_fitting" title="Piping and plumbing fitting">Piping and plumbing fitting</a></li> <li><a href="/wiki/Plug_(sanitation)" title="Plug (sanitation)">Plug (sanitation)</a></li> <li><a href="/wiki/Pressure_regulator" title="Pressure regulator">Pressure regulator</a></li> <li><a href="/wiki/Pressure_vacuum_breaker" title="Pressure vacuum breaker">Pressure vacuum breaker</a></li> <li><a href="/wiki/Pressure-balanced_valve" title="Pressure-balanced valve">Pressure-balanced valve</a></li> <li><a href="/wiki/Pump" title="Pump">Pump</a></li> <li><a href="/wiki/Radiator_(heating)" title="Radiator (heating)">Radiator (heating)</a></li> <li><a class="mw-selflink selflink">Reduced pressure zone device</a></li> <li><a href="/wiki/Reducer" class="mw-redirect" title="Reducer">Reducer</a></li> <li><a href="/wiki/Relief_valve" title="Relief valve">Relief valve</a></li> <li><a href="/wiki/Riser_clamp" title="Riser clamp">Riser clamp</a></li> <li><a href="/wiki/Rooftop_water_tower" title="Rooftop water tower">Rooftop water tower</a></li> <li><a href="/wiki/Safety_valve" title="Safety valve">Safety valve</a></li> <li><a href="/wiki/Sewage_pump" class="mw-redirect" title="Sewage pump">Sewage pump</a></li> <li><a href="/wiki/Street_elbow" title="Street elbow">Street elbow</a></li> <li><a href="/wiki/Submersible_pump" title="Submersible pump">Submersible pump</a></li> <li><a href="/wiki/Tap_(valve)" title="Tap (valve)">Tap (valve)</a></li> <li><a href="/wiki/Thermostatic_mixing_valve" title="Thermostatic mixing valve">Thermostatic mixing valve</a></li> <li><a href="/wiki/Trench_drain" title="Trench drain">Trench drain</a></li> <li><a href="/wiki/Vacuum_breaker" title="Vacuum breaker">Vacuum breaker</a></li> <li><a href="/wiki/Vacuum_ejector" title="Vacuum ejector">Vacuum ejector</a></li> <li><a href="/wiki/Valve" title="Valve">Valve</a></li> <li><a href="/wiki/Water_tank" title="Water tank">Water tank</a></li> <li><a href="/wiki/Zone_valve" title="Zone valve">Zone valve</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Plumbing_fixture" title="Plumbing fixture">Plumbing fixtures</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Accessible_bathtub" title="Accessible bathtub">Accessible bathtub</a></li> <li><a href="/wiki/Bathtub" title="Bathtub">Bathtub</a></li> <li><a href="/wiki/Bidet" title="Bidet">Bidet</a></li> <li><a href="/wiki/Dehumidifier" title="Dehumidifier">Dehumidifier</a></li> <li><a href="/wiki/Dishwasher" title="Dishwasher">Dishwasher</a></li> <li><a href="/wiki/Drinking_fountain" title="Drinking fountain">Drinking fountain</a></li> <li><a href="/wiki/Electric_water_boiler" title="Electric water boiler">Electric water boiler</a></li> <li><a href="/wiki/Evaporative_cooler" title="Evaporative cooler">Evaporative cooler</a></li> <li><a href="/wiki/Flush_toilet" title="Flush toilet">Flush toilet</a></li> <li><a href="/wiki/Garbage_disposal_unit" title="Garbage disposal unit">Garbage disposal unit</a></li> <li><a href="/wiki/Hot_water_storage_tank" title="Hot water storage tank">Hot water storage tank</a></li> <li><a href="/wiki/Humidifier" title="Humidifier">Humidifier</a></li> <li><a href="/wiki/Icemaker" title="Icemaker">Icemaker</a></li> <li><a href="/wiki/Instant_hot_water_dispenser" title="Instant hot water dispenser">Instant hot water dispenser</a></li> <li><a href="/wiki/Laundry_tub" class="mw-redirect" title="Laundry tub">Laundry tub</a></li> <li><a href="/wiki/Shower" title="Shower">Shower</a> <ul><li><a href="/wiki/Water_recycling_shower" title="Water recycling shower">water recycling shower</a></li></ul></li> <li><a href="/wiki/Sink" title="Sink">Sink</a></li> <li><a href="/wiki/Storage_water_heater" title="Storage water heater">Storage water heater</a></li> <li><a href="/wiki/Sump_pump" title="Sump pump">Sump pump</a></li> <li><a href="/wiki/Tankless_water_heater" class="mw-redirect" title="Tankless water heater">Tankless water heater</a></li> <li><a href="/wiki/Urinal" title="Urinal">Urinal</a></li> <li><a href="/wiki/Washing_machine" title="Washing machine">Washing machine</a></li> <li><a href="/wiki/Washlet" title="Washlet">Washlet</a></li> <li><a href="/wiki/Water_dispenser" title="Water dispenser">Water dispenser</a></li> <li><a href="/wiki/Water_filter" title="Water filter">Water filter</a></li> <li><a href="/wiki/Water_heater" class="mw-redirect" title="Water heater">Water heater</a></li> <li><a href="/wiki/Water_softener" class="mw-redirect" title="Water softener">Water softener</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Specialized tools</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Basin_wrench" title="Basin wrench">Basin wrench</a></li> <li><a href="/wiki/Blowtorch" title="Blowtorch">Blowtorch</a></li> <li><a href="/wiki/Borescope" title="Borescope">Borescope</a></li> <li><a href="/wiki/Core_drill" title="Core drill">Core drill</a></li> <li><a href="/wiki/Drain_cleaner" title="Drain cleaner">Drain cleaner</a></li> <li><a href="/wiki/Driving_cap" title="Driving cap">Driving cap</a></li> <li><a href="/wiki/Flare-nut_wrench" class="mw-redirect" title="Flare-nut wrench">Flare-nut wrench</a></li> <li><a href="/wiki/Pipecutter" title="Pipecutter">Pipecutter</a></li> <li><a href="/wiki/Pipe_wrench" title="Pipe wrench">Pipe wrench</a></li> <li><a href="/wiki/Plumber%27s_snake" title="Plumber&#39;s snake">Plumber's snake</a></li> <li><a href="/wiki/Plumber_wrench" title="Plumber wrench">Plumber wrench</a></li> <li><a href="/wiki/Plunger" title="Plunger">Plunger</a></li> <li><a href="/wiki/Strap_wrench" title="Strap wrench">Strap wrench</a></li> <li><a href="/wiki/Tap_and_die" title="Tap and die">Tap and die</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Measurement<br />and control</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Control_valve" title="Control valve">Control valve</a></li> <li><a href="/wiki/Flow_sensor" class="mw-redirect" title="Flow sensor">Flow sensor</a></li> <li><a href="/wiki/Pressure_sensor" class="mw-redirect" title="Pressure sensor">Pressure sensor</a></li> <li><a href="/wiki/Water_detector" title="Water detector">Water detector</a></li> <li><a href="/wiki/Water_metering" title="Water metering">Water metering</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Professions,<br />trades,<br />and services</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Hydronic_balancing" title="Hydronic balancing">Hydronic balancing</a></li> <li><a href="/wiki/Hydrostatic_testing" class="mw-redirect" title="Hydrostatic testing">Hydrostatic testing</a></li> <li><a href="/wiki/Leak_detection" title="Leak detection">Leak detection</a></li> <li><a href="/wiki/Mechanical,_electrical,_and_plumbing" title="Mechanical, electrical, and plumbing">Mechanical, electrical, and plumbing</a></li> <li><a href="/wiki/Pipe_marking" title="Pipe marking">Pipe marking</a></li> <li><a href="/wiki/Pipefitter" title="Pipefitter">Pipefitter</a></li> <li><a href="/wiki/Pipelayer" title="Pipelayer">Pipelayer</a></li> <li><a href="/wiki/Plumber" title="Plumber">Plumber</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Industry <br />organizations <br />and standards</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/International_Association_of_Plumbing_and_Mechanical_Officials" class="mw-redirect" title="International Association of Plumbing and Mechanical Officials">International Association of Plumbing and Mechanical Officials (IAPMO)</a></li> <li><a href="/wiki/NSF_International" title="NSF International">NSF International</a></li> <li><a href="/wiki/Plumbing_%26_Drainage_Institute" title="Plumbing &amp; Drainage Institute">Plumbing &amp; Drainage Institute (PDI)</a></li> <li><a href="/wiki/Uniform_Plumbing_Code" title="Uniform Plumbing Code">Uniform Plumbing Code (UPC)</a></li> <li><a href="/wiki/World_Plumbing_Council" title="World Plumbing Council">World Plumbing Council (WPC)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Health and safety</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Plumbing_code" title="Plumbing code">Plumbing code</a></li> <li><a href="/wiki/Scalding" title="Scalding">Scalding</a></li> <li><a href="/wiki/Waterborne_disease" title="Waterborne disease">Waterborne disease</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">See also</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0;text-align: middle;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Fire_sprinkler_system" title="Fire sprinkler system">Fire sprinkler system</a></li> <li><a href="/wiki/Piping" title="Piping">Piping</a></li> <li><a href="/wiki/Template:HVAC" title="Template:HVAC">Template:HVAC</a></li> <li><a href="/wiki/Template:Public_health" title="Template:Public health">Template:Public health</a></li> <li><a href="/wiki/Template:Sewerage" title="Template:Sewerage">Template:Sewerage</a></li> <li><a href="/wiki/Template:Toilets" class="mw-redirect" title="Template:Toilets">Template:Toilets</a></li> <li><a href="/wiki/Template:Wastewater" title="Template:Wastewater">Template:Wastewater</a></li></ul> </div></td></tr></tbody></table></div> <!-- NewPP limit report Parsed by mw‐web.codfw.main‐f69cdc8f6‐qr4c8 Cached time: 20241122145150 Cache expiry: 2592000 Reduced expiry: false Complications: [vary‐revision‐sha1, show‐toc] CPU time usage: 0.285 seconds Real time usage: 0.551 seconds Preprocessor visited node count: 791/1000000 Post‐expand include size: 42538/2097152 bytes Template argument size: 603/2097152 bytes Highest expansion depth: 8/100 Expensive parser function count: 2/500 Unstrip recursion depth: 1/20 Unstrip post‐expand size: 41582/5000000 bytes Lua time usage: 0.180/10.000 seconds Lua memory usage: 4676242/52428800 bytes Number of Wikibase entities loaded: 0/400 --> <!-- Transclusion expansion time report (%,ms,calls,template) 100.00% 355.232 1 -total 45.88% 162.972 2 Template:Reflist 36.82% 130.813 2 Template:Cite_web 21.52% 76.436 2 Template:Navbox 21.27% 75.552 1 Template:Backflow 17.67% 62.763 1 Template:Short_description 11.88% 42.186 1 Template:Cleanup-rewrite 10.55% 37.489 1 Template:Ambox 9.82% 34.873 2 Template:Pagetype 5.07% 18.002 4 Template:Main_other --> <!-- Saved in parser cache with key enwiki:pcache:idhash:4634175-0!canonical and timestamp 20241122145150 and revision id 1181718267. Rendering was triggered because: page-view --> </div><!--esi <esi:include src="/esitest-fa8a495983347898/content" /> --><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Reduced_pressure_zone_device&amp;oldid=1181718267">https://en.wikipedia.org/w/index.php?title=Reduced_pressure_zone_device&amp;oldid=1181718267</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Plumbing_valves" title="Category:Plumbing valves">Plumbing valves</a></li><li><a href="/wiki/Category:Backflow" title="Category:Backflow">Backflow</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:Wikipedia_articles_needing_rewrite_from_June_2016" title="Category:Wikipedia articles needing rewrite from June 2016">Wikipedia articles needing rewrite from June 2016</a></li><li><a href="/wiki/Category:All_articles_needing_rewrite" title="Category:All articles needing rewrite">All articles needing rewrite</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 24 October 2023, at 20:05<span class="anonymous-show">&#160;(UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=Reduced_pressure_zone_device&amp;mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-f69cdc8f6-2d8xz","wgBackendResponseTime":144,"wgPageParseReport":{"limitreport":{"cputime":"0.285","walltime":"0.551","ppvisitednodes":{"value":791,"limit":1000000},"postexpandincludesize":{"value":42538,"limit":2097152},"templateargumentsize":{"value":603,"limit":2097152},"expansiondepth":{"value":8,"limit":100},"expensivefunctioncount":{"value":2,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":41582,"limit":5000000},"entityaccesscount":{"value":0,"limit":400},"timingprofile":["100.00% 355.232 1 -total"," 45.88% 162.972 2 Template:Reflist"," 36.82% 130.813 2 Template:Cite_web"," 21.52% 76.436 2 Template:Navbox"," 21.27% 75.552 1 Template:Backflow"," 17.67% 62.763 1 Template:Short_description"," 11.88% 42.186 1 Template:Cleanup-rewrite"," 10.55% 37.489 1 Template:Ambox"," 9.82% 34.873 2 Template:Pagetype"," 5.07% 18.002 4 Template:Main_other"]},"scribunto":{"limitreport-timeusage":{"value":"0.180","limit":"10.000"},"limitreport-memusage":{"value":4676242,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-f69cdc8f6-qr4c8","timestamp":"20241122145150","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Reduced pressure zone device","url":"https:\/\/en.wikipedia.org\/wiki\/Reduced_pressure_zone_device","sameAs":"http:\/\/www.wikidata.org\/entity\/Q7306333","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q7306333","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2006-04-05T05:45:57Z","dateModified":"2023-10-24T20:05:23Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/5\/50\/Reduced_pressure_zone_device_connected_to_a_fire_hydrant.jpg","headline":"type of backflow prevention device"}</script> </body> </html>

Pages: 1 2 3 4 5 6 7 8 9 10