{"id":18522,"date":"2025-07-24T08:51:01","date_gmt":"2025-07-24T08:51:01","guid":{"rendered":"https:\/\/oudianvalve.com\/?p=18522"},"modified":"2025-07-24T08:53:17","modified_gmt":"2025-07-24T08:53:17","slug":"check-valve-introduction","status":"publish","type":"post","link":"https:\/\/oudianvalve.com\/pt\/2025\/07\/check-valve-introduction\/","title":{"rendered":"Check Valve \u2013 Introduction"},"content":{"rendered":"<p class=\"ds-markdown-paragraph\">UM\u00a0<strong>check valve<\/strong>\u00a0(also called a\u00a0<strong>non-return valve, one-way valve, or clack valve<\/strong>) is a mechanical device designed to allow fluid flow in\u00a0<strong>one direction only<\/strong>, automatically preventing backflow when the flow stops or reverses.<\/p>\n<figure id=\"attachment_18329\" aria-describedby=\"caption-attachment-18329\" style=\"width: 300px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-18329\" src=\"https:\/\/oudianvalve.com\/wp-content\/uploads\/2023\/09\/904l-swing-check-valve-pn25-dn80-flange-end-1-300x300.jpg\" alt=\"904L Swing Check Valve\" width=\"300\" height=\"300\" \/><figcaption id=\"caption-attachment-18329\" class=\"wp-caption-text\">904L Swing Check Valve- PN16 Flanged Connection &#8211; ASTM 904L<\/figcaption><\/figure>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_83 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/oudianvalve.com\/pt\/2025\/07\/check-valve-introduction\/#Key_Functions_of_a_Check_Valve\" >Key Functions of a Check Valve<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/oudianvalve.com\/pt\/2025\/07\/check-valve-introduction\/#Types_of_Check_Valves\" >Tipos de v\u00e1lvulas de reten\u00e7\u00e3o<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/oudianvalve.com\/pt\/2025\/07\/check-valve-introduction\/#How_Does_a_Check_Valve_Work\" >How Does a Check Valve Work?<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/oudianvalve.com\/pt\/2025\/07\/check-valve-introduction\/#Industry_Codes_and_Standards\" >Industry Codes and Standards<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/oudianvalve.com\/pt\/2025\/07\/check-valve-introduction\/#Common_Applications\" >Aplica\u00e7\u00f5es comuns<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/oudianvalve.com\/pt\/2025\/07\/check-valve-introduction\/#Key_Selection_Factors\" >Key Selection Factors<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/oudianvalve.com\/pt\/2025\/07\/check-valve-introduction\/#Conclusion\" >Conclus\u00e3o<\/a><\/li><\/ul><\/nav><\/div>\n<h4><span class=\"ez-toc-section\" id=\"Key_Functions_of_a_Check_Valve\"><\/span><strong>Key Functions of a Check Valve<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p class=\"ds-markdown-paragraph\">\u2714\u00a0<strong>Prevents Reverse Flow<\/strong>\u00a0\u2013 Ensures fluid moves only in the desired direction.<br \/>\n\u2714\u00a0<strong>Protects Equipment<\/strong>\u00a0\u2013 Prevents damage to pumps, compressors, and piping systems.<br \/>\n\u2714\u00a0<strong>Minimizes Water Hammer<\/strong>\u00a0\u2013 Reduces pressure surges caused by sudden flow stoppage.<br \/>\n\u2714\u00a0<strong>Operates Automatically<\/strong>\u00a0\u2013 No manual or external control needed; works based on flow dynamics.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"Types_of_Check_Valves\"><\/span><strong>Tipos de v\u00e1lvulas de reten\u00e7\u00e3o<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p class=\"ds-markdown-paragraph\">Check valves come in different designs, each suited for specific applications:<\/p>\n<div class=\"markdown-table-wrapper\">\n<table>\n<thead>\n<tr>\n<th><strong>Type<\/strong><\/th>\n<th><strong>Como funciona<\/strong><\/th>\n<th><strong>Usos comuns<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><a href=\"https:\/\/www.stvvalves.com\/wholesale\/check-valves\/cast-steel-check-valve\/\"><strong>Swing Check<\/strong><\/a><\/td>\n<td>A hinged disc swings open with flow and closes when flow stops.<\/td>\n<td>Water, wastewater, low-pressure systems.<\/td>\n<\/tr>\n<tr>\n<td><strong>Lift Check<\/strong><\/td>\n<td>A piston or disc lifts vertically with flow and drops back when flow stops.<\/td>\n<td>High-pressure steam, gas, and oil systems.<\/td>\n<\/tr>\n<tr>\n<td><strong>Ball Check<\/strong><\/td>\n<td>A ball moves with flow and seats when flow reverses.<\/td>\n<td>Pumps, fuel systems, small-diameter lines.<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/www.stvvalves.com\/wholesale\/check-valves\/wafer-check-valve\/\"><strong>Dual-Plate (Wafer) Check<\/strong><\/a><\/td>\n<td>Two spring-loaded plates open with flow and snap shut when flow reverses.<\/td>\n<td>Compact spaces, HVAC, oil &amp; gas pipelines.<\/td>\n<\/tr>\n<tr>\n<td><strong>Stop Check<\/strong><\/td>\n<td>Functions as both a check valve and an isolation valve (manual override).<\/td>\n<td>Boilers, power plants, critical processes.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"How_Does_a_Check_Valve_Work\"><\/span><strong>How Does a Check Valve Work?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol start=\"1\">\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>Forward Flow<\/strong>\u00a0\u2013 Fluid pressure pushes the disc\/ball open.<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>Flow Stops\/Reverses<\/strong>\u00a0\u2013 Gravity\/backpressure forces the disc\/ball back into the seat, sealing the valve.<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>Prevents Backflow<\/strong>\u00a0\u2013 The valve remains closed until forward flow resumes.<\/p>\n<\/li>\n<li>\n<h4><span class=\"ez-toc-section\" id=\"Industry_Codes_and_Standards\"><\/span><a href=\"https:\/\/www.piping-world.com\/check-valve-introduction\">Industry Codes and Standards<\/a><span class=\"ez-toc-section-end\"><\/span><\/h4>\n<ul>\n<li>API 6D &#8211; Specification for Pipeline valves<\/li>\n<li>BS 5152 &#8211; Cast Iron globe and globe stop and check valves (withdrawn)<\/li>\n<li>BS 5352 &#8211; Cast and forged steel gate, globe,check and plug valves, screwed and socket welding ends (&lt;= 50mm)<\/li>\n<li>BS 1868 &#8211; Specification for steel check valves (flanged and butt-welding ends)<\/li>\n<li>MSS SP 61 &#8211; Pressure testing of steel valves<\/li>\n<li>MSS SP 25 &#8211; Standard marking system for valves, fittings, flanges &amp; unions<\/li>\n<li>MSS SP 45 &#8211; Bypass and drain connections<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"Common_Applications\"><\/span><strong>Aplica\u00e7\u00f5es comuns<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p class=\"ds-markdown-paragraph\">\u2714\u00a0<strong>Pump Systems<\/strong>\u00a0\u2013 Protects pumps from reverse flow damage.<br \/>\n\u2714\u00a0<strong>Water &amp; Wastewater<\/strong>\u00a0\u2013 Prevents contamination in pipelines.<br \/>\n\u2714\u00a0<strong>Oil &amp; Gas<\/strong>\u00a0\u2013 Controls flow in refineries and pipelines.<br \/>\n\u2714\u00a0<strong>HVAC Systems<\/strong>\u00a0\u2013 Maintains refrigerant and water flow direction.<br \/>\n\u2714\u00a0<strong>Processamento Qu\u00edmico<\/strong>\u00a0\u2013 Avoids mixing of incompatible fluids.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"Key_Selection_Factors\"><\/span><strong>Key Selection Factors<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p class=\"ds-markdown-paragraph\">When choosing a check valve, consider:<\/p>\n<ul>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>Flow Rate &amp; Pressure<\/strong>\u00a0\u2013 Ensures proper opening\/closing.<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>Compatibilidade de materiais<\/strong>\u00a0\u2013 Must resist corrosion\/erosion.<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>Installation Orientation<\/strong>\u00a0\u2013 Some types (e.g., swing checks) require horizontal\/vertical mounting.<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>Cracking Pressure<\/strong>\u00a0\u2013 Minimum pressure needed to open the valve.<\/p>\n<\/li>\n<\/ul>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span><strong>Conclus\u00e3o<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p class=\"ds-markdown-paragraph\">Check valves are essential for maintaining\u00a0<strong>unidirectional flow<\/strong>\u00a0and protecting systems from backflow damage. The right type depends on\u00a0<strong>pressure, flow conditions, and industry requirements<\/strong>.<\/p>\n<p class=\"ds-markdown-paragraph\">Would you like details on\u00a0<strong>API 594 (check valve testing standards)<\/strong>\u00a0or\u00a0<strong>common failure modes<\/strong>?<\/p>","protected":false},"excerpt":{"rendered":"<p>A\u00a0check valve\u00a0(also called a\u00a0non-return valve, one-way valve, or clack valve) is a mechanical device designed to allow fluid flow in\u00a0one direction only, automatically preventing backflow when the flow stops or reverses. Key Functions of a Check Valve \u2714\u00a0Prevents Reverse Flow\u00a0\u2013 Ensures fluid moves only in the desired direction. \u2714\u00a0Protects Equipment\u00a0\u2013 Prevents damage to pumps, compressors, [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[632,631,633],"class_list":["post-18522","post","type-post","status-publish","format-standard","hentry","category-industry-news","tag-lift-check-valves","tag-swing-check-valve","tag-tilting-disk-check-valves"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/posts\/18522","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/comments?post=18522"}],"version-history":[{"count":1,"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/posts\/18522\/revisions"}],"predecessor-version":[{"id":18523,"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/posts\/18522\/revisions\/18523"}],"wp:attachment":[{"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/media?parent=18522"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/categories?post=18522"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/oudianvalve.com\/pt\/wp-json\/wp\/v2\/tags?post=18522"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}