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<span>Examples</span> </div> </a> <ul id="toc-Examples-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Design_principles" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Design_principles"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Design principles</span> </div> </a> <button aria-controls="toc-Design_principles-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Design principles subsection</span> </button> <ul id="toc-Design_principles-sublist" class="vector-toc-list"> <li id="toc-Lap" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Lap"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Lap</span> </div> </a> <ul id="toc-Lap-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Lead" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Lead"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Lead</span> </div> </a> <ul id="toc-Lead-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Calculating_valve_events" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Calculating_valve_events"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.3</span> <span>Calculating valve events</span> </div> </a> <ul id="toc-Calculating_valve_events-sublist" class="vector-toc-list"> </ul> </li> </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">4</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 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data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For other applications of piston valves, see <a href="/wiki/Piston_valve" title="Piston valve">Piston valve</a>.</div> <figure typeof="mw:File/Thumb"><a href="/wiki/File:Cylinder_and_piston_valve_(New_Catechism_of_the_Steam_Engine,_1904).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Cylinder_and_piston_valve_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg/250px-Cylinder_and_piston_valve_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg" decoding="async" width="250" height="194" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Cylinder_and_piston_valve_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg/375px-Cylinder_and_piston_valve_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Cylinder_and_piston_valve_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg/500px-Cylinder_and_piston_valve_%28New_Catechism_of_the_Steam_Engine%2C_1904%29.jpg 2x" data-file-width="667" data-file-height="518" /></a><figcaption>Diagram of cylinder and piston valve. The valve is next opened by moving it to the right, allowing the clear space in the middle of the valve to align with the channel in the cylinder above it.</figcaption></figure> <p><b>Piston valves</b> are one form of <a href="/wiki/Valve" title="Valve">valve</a> used to control the flow of steam within a <a href="/wiki/Steam_engine" title="Steam engine">steam engine</a> or <a href="/wiki/Steam_locomotive" title="Steam locomotive">locomotive</a>. They control the admission of <a href="/wiki/Steam" title="Steam">steam</a> into the cylinders and its subsequent exhausting, enabling a locomotive to move under its own power. The valve consists of two piston heads on a common spindle moving inside a steam chest, which is essentially a mini-cylinder located either above or below the main cylinders of the locomotive. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Overview">Overview</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Piston_valve_(steam_engine)&action=edit&section=1" title="Edit section: Overview"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In the 19th century, <a href="/wiki/Steam_locomotive" title="Steam locomotive">steam locomotives</a> used <a href="/wiki/Slide_valve" title="Slide valve">slide valves</a> to control the flow of steam into and out of the <a href="/wiki/Cylinder_(steam_locomotive)" class="mw-redirect" title="Cylinder (steam locomotive)">cylinders</a>. In the 20th century, slide valves were gradually superseded by piston valves, particularly in engines using <a href="/wiki/Superheater" title="Superheater">superheated</a> steam. There were two reasons for this: </p> <ul><li>It is difficult to <a href="/wiki/Lubrication" title="Lubrication">lubricate</a> slide valves adequately in the presence of <a href="/wiki/Superheater" title="Superheater">superheated</a> steam</li> <li>With piston valves, the steam passages can be made shorter. This, particularly following the work of <a href="/wiki/Andr%C3%A9_Chapelon" title="André Chapelon">André Chapelon</a>, reduces resistance to the flow of steam and improves efficiency</li></ul> <p>The usual locomotive valve gears such as <a href="/wiki/Stephenson_valve_gear" title="Stephenson valve gear">Stephenson</a>, <a href="/wiki/Walschaerts_valve_gear" title="Walschaerts valve gear">Walschaerts</a>, and <a href="/wiki/Baker_valve_gear" title="Baker valve gear">Baker valve gear</a>, can be used with either slide valves or piston valves. Where <a href="/wiki/Poppet_valve" title="Poppet valve">poppet valves</a> are used, a different gear, such as <a href="/wiki/Caprotti_valve_gear" title="Caprotti valve gear">Caprotti valve gear</a> may be used, though standard gears as mentioned above were used as well, by Chapelon and others. </p><p>Most piston valves are of the "inside admission" type, where fresh steam is introduced from the boiler via the space between the two piston heads of the valve, and exhaust steam leaves via the space between a piston head and the end of the steam chest. The advantage of this arrangement is that leakage, via the gland which seals the steam chest from the operating rod of the valve gear, is much less of a problem when the gland is subjected to low exhaust pressure rather than full boiler pressure. However, some locomotives, like Bulleid's <a href="/wiki/SR_Merchant_Navy_class" title="SR Merchant Navy class">SR Merchant Navy class</a>, used "outside admission" where the reverse was true, in Bulleid's case because of the unusual chain-driven valve gear arrangement. </p> <div class="mw-heading mw-heading2"><h2 id="Examples">Examples</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Piston_valve_(steam_engine)&action=edit&section=2" title="Edit section: Examples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:SwanningtonEngine_01.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/82/SwanningtonEngine_01.jpg/220px-SwanningtonEngine_01.jpg" decoding="async" width="220" height="157" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/82/SwanningtonEngine_01.jpg/330px-SwanningtonEngine_01.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/82/SwanningtonEngine_01.jpg/440px-SwanningtonEngine_01.jpg 2x" data-file-width="1000" data-file-height="714" /></a><figcaption>The <a href="/wiki/Leicester_and_Swannington_Railway" title="Leicester and Swannington Railway">Swannington incline</a> winding engine of 1833 incorporated a piston valve</figcaption></figure> <p>The Swannington incline winding engine on the <a href="/wiki/Leicester_and_Swannington_Railway" title="Leicester and Swannington Railway">Leicester and Swannington Railway</a>, manufactured by The Horsely Coal & Iron Company in 1833, shows a very early use of the piston valve.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> Piston valves had been used a year or two previously in the horizontal engines manufactured by <a href="/wiki/Taylor_%26_Martineau" class="mw-redirect" title="Taylor & Martineau">Taylor & Martineau</a> of London, but did not become general for stationary or locomotive engines until the end of the 19th century.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Design_principles">Design principles</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Piston_valve_(steam_engine)&action=edit&section=3" title="Edit section: Design principles"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Steam_engine_Lap_and_lead_diagram.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/44/Steam_engine_Lap_and_lead_diagram.png/220px-Steam_engine_Lap_and_lead_diagram.png" decoding="async" width="220" height="311" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/44/Steam_engine_Lap_and_lead_diagram.png/330px-Steam_engine_Lap_and_lead_diagram.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/44/Steam_engine_Lap_and_lead_diagram.png/440px-Steam_engine_Lap_and_lead_diagram.png 2x" data-file-width="794" data-file-height="1123" /></a><figcaption>Diagram showing lap and lead and their relation to valve travel</figcaption></figure> <p>When on the move, a steam locomotive requires steam to enter the <a href="/wiki/Cylinder_(engine)" title="Cylinder (engine)">cylinder</a> at precise times relative to the piston's position.<sup id="cite_ref-Garratt,C_3-0" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> This entails controlling the admission and exhaust of steam to and from the cylinders with a valve linked to the motion of the piston.<sup id="cite_ref-Garratt,C_3-1" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>For timing and dimensioning of slide or piston valves where the valve opens and closes the steam and exhaust ports, a consideration of the "lap" and "lead" is required. </p> <div class="mw-heading mw-heading3"><h3 id="Lap">Lap</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Piston_valve_(steam_engine)&action=edit&section=4" title="Edit section: Lap"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Lap is the amount by which the valve overlaps each port at the middle position of each valve.<sup id="cite_ref-Garratt,C_3-2" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> There are two different types of lap. </p><p>The first kind is the steam lap, which is the amount by which the valve overlaps the steam port on the <a href="/wiki/Live_steam" title="Live steam">live steam</a> side of the piston or slide valve (i.e. the distance the valve needs to move to just begin to uncover the port).<sup id="cite_ref-Garratt,C_3-3" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>Secondly, the exhaust lap, which is the amount by which the valve overlaps the exhaust port on the <a href="/wiki/Exhaust_system" title="Exhaust system">exhaust</a> side of the piston or slide valve. Exhaust lap is generally given to slow-running locomotives.<sup id="cite_ref-Garratt,C_3-4" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> This is because it allows the steam to remain in the cylinder for the longest possible amount of time before being expended as exhaust, therefore increasing efficiency.<sup id="cite_ref-Garratt,C_3-5" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Shunter" class="mw-redirect" title="Shunter">shunter</a> locomotives tended to be equipped with this addition. </p><p>Negative exhaust lap, also commonly known as exhaust clearance, is the amount the port is open to exhaust when the valve is in mid-position, and is used on many fast-running locomotives to give a free exhaust.<sup id="cite_ref-Garratt,C_3-6" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> The cylinder on both sides of the piston is open to exhaust at the same time when the valve is passing through the mid-position, which is only momentary when running.<sup id="cite_ref-Garratt,C_3-7" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Lead">Lead</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Piston_valve_(steam_engine)&action=edit&section=5" title="Edit section: Lead"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Lead is the amount by which a port is open when the piston is at front or back "dead centre".<sup id="cite_ref-Garratt,C_3-8" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> In the case of the steam port this allows admission of steam to fill the clearance space between the cylinder and piston and ensures maximum cylinder pressure before the commencement of the stroke.<sup id="cite_ref-Garratt,C_3-9" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> This both cushions and assists the mass of the piston to slow down and change direction. At slow speeds no lead is ideal. For engines with pistons of 24 inches plus and masses of over 5 kilos and pressures under 500 psi then cushioning is beneficial. Lead is necessary on locomotives designed for high speeds.<sup id="cite_ref-Garratt,C_3-10" class="reference"><a href="#cite_note-Garratt,C-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Calculating_valve_events">Calculating valve events</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Piston_valve_(steam_engine)&action=edit&section=6" title="Edit section: Calculating valve events"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Given the valve's lap, lead, and travel, at what point in the piston's stroke does the valve open and close, to steam and to exhaust? </p><p>Calculating an exact answer to that question before computers was too much work. The easy approximation (used in <a href="/wiki/Gustav_Zeuner" title="Gustav Zeuner">Zeuner</a>'s and <a href="/wiki/Franz_Reuleaux" title="Franz Reuleaux">Realeaux</a>'s diagrams) is to pretend that both the valve and the piston have a sine-wave motion (as they would, if the main rod were infinitely long). Then, for instance, to calculate the percent of the piston's stroke at which steam admission is cut off: </p> <ul><li>Calculate the angle whose cosine is twice the lap divided by the valve travel</li> <li>Calculate the angle whose cosine is twice the (lap plus lead), divided by the valve travel</li></ul> <p>Add the two angles and take the cosine of their sum; subtract 1 from that cosine and multiply the result by -50. </p><p>As built the <a href="/wiki/Pennsylvania_Railroad" title="Pennsylvania Railroad">Pennsylvania</a>'s <a href="/wiki/Pennsylvania_Railroad_class_I1s" class="mw-redirect" title="Pennsylvania Railroad class I1s">I1s</a> 2-10-0 had lap 2 inches, lead 1/4 inch and valve travel 6 inches in full gear. In full gear the two angles are 48.19 deg and 41.41 deg and the maximum cutoff comes out 49.65% of the piston stroke. </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=Piston_valve_(steam_engine)&action=edit&section=7" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Slide_valve" title="Slide valve">Slide valve</a></li> <li><a href="/wiki/Steam_locomotive_components" title="Steam locomotive components">Steam locomotive components</a></li> <li><a href="/wiki/Valve_gear" title="Valve gear">Valve gear</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=Piston_valve_(steam_engine)&action=edit&section=8" 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"> <div class="mw-references-wrap"><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">Clinker, C.R. (1977) <i>The Leicester & Swannington Railway</i> Bristol: Avon Anglia Publications & Services. Reprinted from the Transactions of the Leicestershire Archaeological Society Volume XXX, 1954.</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">Information plaque on the Swannington engine, <a href="/wiki/National_Railway_Museum" title="National Railway Museum">National Railway Museum</a>, <a href="/wiki/York" title="York">York</a>.</span> </li> <li id="cite_note-Garratt,C-3"><span class="mw-cite-backlink">^ <a href="#cite_ref-Garratt,C_3-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-6"><sup><i><b>g</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-7"><sup><i><b>h</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-8"><sup><i><b>i</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-9"><sup><i><b>j</b></i></sup></a> <a href="#cite_ref-Garratt,C_3-10"><sup><i><b>k</b></i></sup></a></span> <span class="reference-text">Garratt, C. & Wade-Matthews, M.: <i>The Ultimate Encyclopedia of Steam & Rail</i> (London: Hermes Publishing Company, Ltd., 1998) <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><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/1-84038-088-8" title="Special:BookSources/1-84038-088-8">1-84038-088-8</a></span> </li> </ol></div></div> <div class="navbox-styles"><style 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engines</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Operating cycle</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/Newcomen_atmospheric_engine" title="Newcomen atmospheric engine">Atmospheric</a></li> <li><a href="/wiki/Watt_steam_engine" title="Watt steam engine">Watt</a></li> <li><a href="/wiki/Cornish_engine" title="Cornish engine">Cornish</a></li> <li><a href="/wiki/Compound_steam_engine" title="Compound steam engine">Compound</a></li> <li><a href="/wiki/Uniflow_steam_engine" title="Uniflow steam engine">Uniflow</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Valve" title="Valve">Valves</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em">Valves</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Slide_valve" title="Slide valve">Slide</a> <ul><li><a href="/wiki/Slide_valve#Murdoch's_D_slide_valve" title="Slide valve">D slide</a></li></ul></li> <li><a class="mw-selflink selflink">Piston</a></li> <li><a href="/wiki/Double_beat_valve" title="Double beat valve">Drop</a></li> <li><a href="/wiki/Corliss_steam_engine" title="Corliss steam engine">Corliss</a></li> <li><a href="/wiki/Poppet_valve" title="Poppet valve">Poppet</a></li> <li><a href="/wiki/Sleeve_valve" title="Sleeve valve">Sleeve</a></li> <li><a href="/wiki/Bash_valve" title="Bash valve">Bash</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Valve_gear" title="Valve gear">Valve gear</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Gab_valve_gear" title="Gab valve gear">Gab</a></li> <li><a href="/wiki/Stephenson_valve_gear" title="Stephenson valve gear">Stephenson link</a></li> <li><a href="/wiki/Joy_valve_gear" title="Joy valve gear">Joy</a></li> <li><a href="/wiki/Walschaerts_valve_gear" title="Walschaerts valve gear">Walschaerts</a></li> <li><a href="/wiki/Stephenson_valve_gear#Allan_straight_link_valve_gear" title="Stephenson valve gear">Allan</a></li> <li><a href="/wiki/Baker_valve_gear" title="Baker valve gear">Baker</a></li> <li><a href="/wiki/Corliss_steam_engine" title="Corliss steam engine">Corliss</a></li> <li><a href="/wiki/Hugo_Lentz" title="Hugo Lentz">Lentz</a></li> <li><a href="/wiki/Caprotti_valve_gear" title="Caprotti valve gear">Caprotti</a></li> <li><a href="/wiki/Gresley_conjugated_valve_gear" title="Gresley conjugated valve gear">Gresley conjugated</a></li> <li><a href="/wiki/Southern_valve_gear" title="Southern valve gear">Southern</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Mechanism_(engineering)" title="Mechanism (engineering)">Mechanisms</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Beam_engine" title="Beam engine">Beam</a></li> <li><a href="/wiki/Cataract_(beam_engine)" title="Cataract (beam engine)">Cataract</a></li> <li><a href="/wiki/Centrifugal_governor" title="Centrifugal governor">Centrifugal governor</a></li> <li><a href="/wiki/Connecting_rod#Steam_engines" title="Connecting rod">Connecting rod</a></li> <li><a href="/wiki/Crank_(mechanism)" title="Crank (mechanism)">Crank</a></li> <li><a href="/wiki/Crankshaft" title="Crankshaft">Crankshaft</a></li> <li><a href="/wiki/Tusi_couple" title="Tusi couple">Tusi couple</a> <a href="/wiki/Hypocycloidal" class="mw-redirect" title="Hypocycloidal">hypocycloidal</a> <a href="/wiki/Straight_line_mechanism" class="mw-redirect" title="Straight line mechanism">straight line mechanism</a></li> <li><a href="/wiki/Link_chain" class="mw-redirect" title="Link chain">Link chain</a></li> <li><a href="/wiki/Parallel_motion" class="mw-redirect" title="Parallel motion">Parallel motion</a></li> <li><a href="/wiki/Roller_chain" title="Roller chain">Plate chain</a></li> <li><a href="/wiki/Beam_engine#Rotative_beam_engines" title="Beam engine">Rotative beam</a></li> <li><a href="/wiki/Sun_and_planet_gear" title="Sun and planet gear">Sun and planet gear</a></li> <li><a href="/wiki/Watt%27s_linkage" title="Watt's linkage">Watt's linkage</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Boiler" title="Boiler">Boilers</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em">Simple boilers</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Haystack_boiler" class="mw-redirect" title="Haystack boiler">Haystack</a></li> <li><a href="/wiki/Wagon_boiler" class="mw-redirect" title="Wagon boiler">Wagon</a></li> <li><a href="/wiki/Egg-ended_boiler" class="mw-redirect" title="Egg-ended boiler">Egg-ended</a></li> <li><a href="/wiki/Box_boiler" class="mw-redirect" title="Box boiler">Box</a></li> <li><a href="/wiki/Flued_boiler" title="Flued boiler">Flued</a></li> <li><a href="/wiki/Cornish_boiler" class="mw-redirect" title="Cornish boiler">Cornish</a></li> <li><a href="/wiki/Lancashire_boiler" class="mw-redirect" title="Lancashire boiler">Lancashire</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Fire-tube_boiler" title="Fire-tube boiler">Fire-tube boilers</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Locomotive_boiler" class="mw-redirect" title="Locomotive boiler">Locomotive</a></li> <li><a href="/wiki/Scotch_marine_boiler" title="Scotch marine boiler">Scotch</a></li> <li><a href="/wiki/Launch-type_boiler" title="Launch-type boiler">Launch</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Water-tube_boiler" title="Water-tube boiler">Water-tube boilers</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Babcock_%26_Wilcox_boiler" class="mw-redirect" title="Babcock & Wilcox boiler">Babcock & Wilcox</a></li> <li><a href="/wiki/Field-tube_boiler" title="Field-tube boiler">Field-tube</a></li> <li><a href="/wiki/Sentinel_boiler" title="Sentinel boiler">Sentinel</a></li> <li><a href="/wiki/Stirling_boiler" title="Stirling boiler">Stirling</a></li> <li><a href="/wiki/Thimble_tube_boiler" title="Thimble tube boiler">Thimble tube</a></li> <li><a href="/wiki/Three-drum_boiler" title="Three-drum boiler">Three-drum</a></li> <li><a href="/wiki/Yarrow_boiler" title="Yarrow boiler">Yarrow</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">Boiler feed</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Feedwater_heater" title="Feedwater heater">Feedwater heater</a></li> <li><a href="/wiki/Boiler_feedwater_pump" title="Boiler feedwater pump">Feedwater pump</a></li> <li><a href="/wiki/Injector" title="Injector">Injector</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Cylinder_(engine)" title="Cylinder (engine)">Cylinder</a></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/Cylinder_(locomotive)" title="Cylinder (locomotive)">Locomotive</a></li> <li><a href="/wiki/Oscillating_cylinder_steam_engine" title="Oscillating cylinder steam engine">Oscillating</a></li> <li><a href="/wiki/Single-_and_double-acting_cylinders" title="Single- and double-acting cylinders">Single- and double-acting</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Condenser_(heat_transfer)" title="Condenser (heat transfer)">Condenser</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Condensing_steam_locomotive" title="Condensing steam locomotive">Condensing steam locomotive</a></li> <li><a href="/wiki/Jet_condenser" class="mw-redirect" title="Jet condenser">Jet</a></li> <li><a href="/wiki/Kirchweger_condenser" title="Kirchweger condenser">Kirchweger</a></li> <li><a href="/wiki/Watt_steam_engine#Separate_condenser" title="Watt steam engine">Watt's separate</a></li> <li><a href="/wiki/Thomas_Newcomen#After_Newcomen" title="Thomas Newcomen">"Pickle-pot"</a></li> <li><a href="/wiki/Surface_condenser" title="Surface condenser">Surface</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</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/Blowback_(steam_engine)" title="Blowback (steam engine)">Blowback</a></li> <li><a href="/wiki/Crosshead" title="Crosshead">Crosshead</a></li> <li><a href="/wiki/Cutoff_(steam_engine)" title="Cutoff (steam engine)">Cutoff</a></li> <li><a href="/wiki/Expansion_valve_(steam_engine)" title="Expansion valve (steam engine)">Expansion valve</a></li> <li><a href="/wiki/Hydrolock" title="Hydrolock">Hydrolock</a></li> <li><a href="/wiki/Piston" title="Piston">Piston</a></li> <li><a href="/wiki/Reciprocating_engine" title="Reciprocating engine">Reciprocating engine</a></li> <li><a href="/wiki/Return_connecting_rod_engine" title="Return connecting rod engine">Return connecting rod engine</a></li> <li><a href="/wiki/Six-column_beam_engine" title="Six-column beam engine">Six-column beam engine</a></li> <li><a href="/wiki/Return_connecting_rod_engine#Steeple_engines" title="Return connecting rod engine">Steeple engine</a></li> <li><a href="/wiki/Safety_valve" title="Safety valve">Safety valve</a></li> <li><a href="/wiki/Steeple_compound_engine" title="Steeple compound engine">Steeple compound engine</a></li> <li><a href="/wiki/Stroke_(engine)" title="Stroke (engine)">Stroke</a></li> <li><a href="/wiki/Working_fluid" title="Working fluid">Working fluid</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/History_of_the_steam_engine" title="History of the steam engine">History</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/History_of_the_steam_engine#Precursors" title="History of the steam engine">Precursors</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Thomas_Savery" title="Thomas Savery">Savery Engine</a> (1698)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Newcomen_atmospheric_engine" title="Newcomen atmospheric engine">Newcomen engine</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Newcomen_Memorial_Engine" title="Newcomen Memorial Engine">Newcomen Memorial Engine</a> (1725)</li> <li><i><a href="/wiki/Fairbottom_Bobs" title="Fairbottom Bobs">Fairbottom Bobs</a></i> (1760)</li> <li><a href="/wiki/Elsecar_Engine" class="mw-redirect" title="Elsecar Engine">Elsecar Engine</a> (1795)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Watt_steam_engine" title="Watt steam engine">Watt engine</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8em"><a href="/wiki/Beam_engine" title="Beam engine">Beam</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Kinneil_Engine" class="mw-redirect" title="Kinneil Engine">Kinneil Engine</a> (1768)</li> <li><a href="/wiki/Old_Bess_(beam_engine)" title="Old Bess (beam engine)"><i>Old Bess</i></a> (1777)</li> <li><a href="/wiki/Wheal_Busy" title="Wheal Busy">Chacewater Mine engine</a> (1778)</li> <li><a href="/wiki/Smethwick_Engine" title="Smethwick Engine">Smethwick Engine</a> (1779)</li> <li><a href="/wiki/Resolution_(beam_engine)" title="Resolution (beam engine)"><i>Resolution</i></a> (1781)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8em"><a href="/wiki/Beam_engine#Rotative_beam_engines" title="Beam engine">Rotative beam</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Soho_Manufactory#Steam_engines" title="Soho Manufactory">Soho Manufactory engine</a> (1782)</li> <li><a href="/wiki/John_Wilkinson_(industrialist)#Boring_machine_for_steam_engines" title="John Wilkinson (industrialist)">Bradley Works engine</a> (1783)</li> <li><a href="/wiki/Whitbread_Engine" title="Whitbread Engine">Whitbread Engine</a> (1785)</li> <li><a href="/wiki/Beam_engine#Preserved_beam_engines" title="Beam engine">National Museum of Scotland engine</a> (1786)</li> <li><a href="/wiki/Lap_Engine" title="Lap Engine">Lap Engine</a> (1788)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/History_of_the_steam_engine#High-pressure_engines" title="History of the steam engine">High-pressure</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Richard_Trevithick#High-pressure_engine" title="Richard Trevithick">Richard Trevithick</a> <ul><li><a href="/wiki/Richard_Trevithick#Puffing_Devil" title="Richard Trevithick"><i>Puffing Devil</i></a> (1801)</li> <li><a href="/wiki/Richard_Trevithick#London_Steam_Carriage" title="Richard Trevithick">London Steam Carriage</a> (1803)</li> <li><a href="/wiki/Richard_Trevithick#Coalbrookdale_Locomotive" title="Richard Trevithick">"Coalbrookdale Locomotive"</a> (1803)</li> <li><a href="/wiki/Richard_Trevithick#"Pen-y-Darren"_locomotive" title="Richard Trevithick">"Pen-y-Darren" locomotive</a> (1804)</li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Compound_steam_engine" title="Compound steam engine">Compound</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Arthur_Woolf" title="Arthur Woolf">Woolf's compound engine</a> (1803)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Matthew_Murray" title="Matthew Murray">Murray</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Murray%27s_Hypocycloidal_Engine" title="Murray's Hypocycloidal Engine">Murray's Hypocycloidal Engine</a> (1805)</li> <li><a href="/wiki/Salamanca_(locomotive)" title="Salamanca (locomotive)"><i>Salamanca</i></a> (1812)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/High-speed_steam_engine" title="High-speed steam engine">High-speed</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Porter-Allen_engine" class="mw-redirect" title="Porter-Allen engine">Porter-Allen</a> (1862)</li> <li><a href="/wiki/Ljungstr%C3%B6m_turbine" title="Ljungström turbine">Ljungström</a> (1908)</li></ul> </div></td></tr></tbody></table><div></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"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Glossary_of_steam_locomotive_components" class="mw-redirect" title="Glossary of steam locomotive components">Glossary of steam locomotive components</a></li> <li><a href="/wiki/History_of_steam_road_vehicles" title="History of steam road vehicles">History of steam road vehicles</a> <ul><li><a href="/wiki/Nicolas-Joseph_Cugnot#The_first_self-propelled_vehicle" title="Nicolas-Joseph Cugnot">Cugnot's <i>fardier à vapeur</i></a> (1769)</li> <li><a href="/wiki/William_Murdoch#Steam_powered_locomotion" title="William Murdoch">Murdoch's model steam carriage</a> (1784)</li></ul></li> <li><i><a href="/wiki/Lean%27s_Engine_Reporter" title="Lean's Engine Reporter">Lean's Engine Reporter</a></i></li> <li><a href="/wiki/List_of_steam_technology_patents" title="List of steam technology patents">List of steam technology patents</a></li> <li><a href="/wiki/Advanced_steam_technology" title="Advanced steam technology">Modern steam</a></li> <li><a href="/wiki/Stationary_steam_engine" title="Stationary steam engine">Stationary steam engine</a></li> <li><a href="/wiki/Timeline_of_steam_power" title="Timeline of steam power">Timeline of steam power</a></li> <li><a href="/wiki/Water-returning_engine" title="Water-returning engine">Water-returning engine</a></li></ul> </div></td></tr></tbody></table></div>    </div><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=Piston_valve_(steam_engine)&oldid=1250117056">https://en.wikipedia.org/w/index.php?title=Piston_valve_(steam_engine)&oldid=1250117056</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:Locomotive_valve_gear" title="Category:Locomotive valve 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