{"id":189,"date":"2015-09-02T14:17:00","date_gmt":"2015-09-02T14:17:00","guid":{"rendered":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/uncategorized\/basic-diagrams-and-systemsautomatic-venting-at-end-of-cycle\/"},"modified":"2015-09-02T14:17:00","modified_gmt":"2015-09-02T14:17:00","slug":"basic-diagrams-and-systemsautomatic-venting-at-end-of-cycle","status":"publish","type":"post","link":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/basic-diagrams-and-systemsautomatic-venting-at-end-of-cycle\/","title":{"rendered":"BASIC DIAGRAMS AND SYSTEMS:Automatic Venting at End of Cycle."},"content":{"rendered":"<div class=\"bugzt6a0dbd950d0ea\" ><script type=\"text\/javascript\">\n\tatOptions = {\n\t\t'key' : '61e5902552e2353963d8d2f1bd1f4a8f',\n\t\t'format' : 'iframe',\n\t\t'height' : 250,\n\t\t'width' : 300,\n\t\t'params' : {}\n\t};\n<\/script>\n<script type=\"text\/javascript\" src=\"\/\/www.highperformanceformat.com\/61e5902552e2353963d8d2f1bd1f4a8f\/invoke.js\"><\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.bugzt6a0dbd950d0ea {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.bugzt6a0dbd950d0ea {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.bugzt6a0dbd950d0ea {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.bugzt6a0dbd950d0ea {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.bugzt6a0dbd950d0ea {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<p align=\"justify\"><b><i>Automatic Venting at End of Cycle<\/i><\/b>  <\/p>\n<p align=\"justify\">In systems where it is not necessary to hold pressure at the end of a cycle, it is possi&shy;ble to unload the pump by automatically venting the relief valve. Figure 9-10 shows such a system using a cam-operated pilot valve to vent the relief valve.  <\/p>\n<p align=\"justify\"><a href=\"http:\/\/lh3.googleusercontent.com\/-nbjDPbsLXJU\/VecDDQsAXrI\/AAAAAAAB6go\/Z1zeMqPpgYc\/s1600-h\/FLUID-POWER-DYNAMICS-03762.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"FLUID POWER DYNAMICS-0376\" border=\"0\" alt=\"FLUID POWER DYNAMICS-0376\" src=\"http:\/\/lh3.googleusercontent.com\/-e1oSjjlt-0U\/VecDKowG4vI\/AAAAAAAB6hU\/KOKjkhGmUDY\/FLUID-POWER-DYNAMICS-0376_thumb.jpg?imgmax=800\" width=\"169\" height=\"244\" \/><\/a>  <\/p>\n<p align=\"justify\"><a href=\"http:\/\/lh3.googleusercontent.com\/-SACiFtlHJjc\/VecDOCFd9bI\/AAAAAAAB6hk\/p4KDFHt1pm8\/s1600-h\/FLUID-POWER-DYNAMICS-03772.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"FLUID POWER DYNAMICS-0377\" border=\"0\" alt=\"FLUID POWER DYNAMICS-0377\" src=\"http:\/\/lh3.googleusercontent.com\/-W2M7GhJ_Phw\/VecEQdflIwI\/AAAAAAAB6iE\/q6XUE5NcyTM\/FLUID-POWER-DYNAMICS-0377_thumb.jpg?imgmax=800\" width=\"177\" height=\"244\" \/><\/a>  <\/p>\n<p align=\"justify\"><i><strong>Midstroke Extending<\/strong><\/i>  <\/p>\n<p align=\"justify\">In view A of Figure 9-10, the machine cycle begins when the solenoid of the spring off&shy; set directional valve is energized. Pump output is to the cap end of the cylinder. The vent line from the directional control valve is blocked at the cam-operated pilot valve.  <\/p>\n<p align=\"justify\"><i><strong>Midstroke Retracting<\/strong><\/i>  <\/p>\n<p align=\"justify\">In view B of Figure 9-10, the limit switch has contracted the cam at the end of the extension stroke. This contact breaks the circuit of the solenoid. The directional  <\/p>\n<p align=\"justify\"><a href=\"http:\/\/lh3.googleusercontent.com\/-XT40TYDjF8g\/VecES0COpXI\/AAAAAAAB6iU\/kTXh1P032NA\/s1600-h\/FLUID-POWER-DYNAMICS-03782.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"FLUID POWER DYNAMICS-0378\" border=\"0\" alt=\"FLUID POWER DYNAMICS-0378\" src=\"http:\/\/lh3.googleusercontent.com\/-SIwCemFCR8Q\/VecEZDVhuiI\/AAAAAAAB6jA\/bFaROeTNIBk\/FLUID-POWER-DYNAMICS-0378_thumb.jpg?imgmax=800\" width=\"169\" height=\"244\" \/><\/a>  <\/p>\n<p align=\"justify\"><a href=\"http:\/\/lh3.googleusercontent.com\/-_68NrnnvLHQ\/VecEbdPfb9I\/AAAAAAAB6jU\/zAQqQ8v0nfc\/s1600-h\/FLUID-POWER-DYNAMICS-03792.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"FLUID POWER DYNAMICS-0379\" border=\"0\" alt=\"FLUID POWER DYNAMICS-0379\" src=\"http:\/\/lh3.googleusercontent.com\/-1Wv0yVpICkA\/VecEhRgSUlI\/AAAAAAAB6kE\/7-H4eHogaqM\/FLUID-POWER-DYNAMICS-0379_thumb.jpg?imgmax=800\" width=\"244\" height=\"225\" \/><\/a>  <\/p><div class=\"mgqki6a0dbd950d322\" ><script type=\"text\/javascript\">\n\tatOptions = {\n\t\t'key' : '0c1eb4c533eaedb7b996f49a5a4983a9',\n\t\t'format' : 'iframe',\n\t\t'height' : 300,\n\t\t'width' : 160,\n\t\t'params' : {}\n\t};\n<\/script>\n<script type=\"text\/javascript\" src=\"\/\/www.highperformanceformat.com\/0c1eb4c533eaedb7b996f49a5a4983a9\/invoke.js\"><\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.mgqki6a0dbd950d322 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.mgqki6a0dbd950d322 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.mgqki6a0dbd950d322 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.mgqki6a0dbd950d322 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.mgqki6a0dbd950d322 {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<div class=\"gmnwh6a0dbd950d221\" ><script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-0778475562755157\"\n     crossorigin=\"anonymous\"><\/script>\n<!-- 300x600 hydraulics-and-pneumatics -->\n<ins class=\"adsbygoogle\"\n     style=\"display:inline-block;width:300px;height:600px\"\n     data-ad-client=\"ca-pub-0778475562755157\"\n     data-ad-slot=\"3735577695\"><\/ins>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.gmnwh6a0dbd950d221 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.gmnwh6a0dbd950d221 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.gmnwh6a0dbd950d221 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.gmnwh6a0dbd950d221 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.gmnwh6a0dbd950d221 {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n\n<p align=\"justify\">control valve has shifted to retract the cylinder. The relief valve vent connection is still blocked.<\/p>\n<p align=\"justify\"><i><strong>Automatic Stop<\/strong><\/i>  <\/p>\n<p align=\"justify\">View C of Figure 9-10 illustrates the circuit at the end of the retraction stroke. The cam on the cylinder opens the venting pilot valve. The relief valve vent port is thus connected to the line from the cap end of the cylinder and the valve is vented through the inline check  <\/p>\n<p align=\"justify\"><a href=\"http:\/\/lh3.googleusercontent.com\/-kmb2uhkaFQI\/VecEjhMtJSI\/AAAAAAAB6kU\/SwRtJh1w1iU\/s1600-h\/FLUID-POWER-DYNAMICS-03802.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"FLUID POWER DYNAMICS-0380\" border=\"0\" alt=\"FLUID POWER DYNAMICS-0380\" src=\"http:\/\/lh3.googleusercontent.com\/-gzCWlZxR3Cw\/VecEotqwdZI\/AAAAAAAB6k8\/xDjHo4iG5kw\/FLUID-POWER-DYNAMICS-0380_thumb.jpg?imgmax=800\" width=\"147\" height=\"244\" \/><\/a><a href=\"http:\/\/lh3.googleusercontent.com\/-48N3fKtX6Ck\/VecEqkWDlxI\/AAAAAAAB6lM\/K74hCFOkySM\/s1600-h\/FLUID-POWER-DYNAMICS-03812.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"FLUID POWER DYNAMICS-0381\" border=\"0\" alt=\"FLUID POWER DYNAMICS-0381\" src=\"http:\/\/lh3.googleusercontent.com\/-2kTl-gvnPSY\/VecEuW2n1AI\/AAAAAAAB6lo\/P2DHDvPMYx4\/FLUID-POWER-DYNAMICS-0381_thumb.jpg?imgmax=800\" width=\"149\" height=\"244\" \/><\/a>  <\/p>\n<p align=\"justify\">valve, the directional control valve, and the right-angle check valve. Pilot pressure for the directional valve is maintained at a value determined by the spring loads in the balanced piston of the relief valve, the vent line check valve, and the tank line check valve.  <\/p>\n<p align=\"justify\"><i><strong>Push-Button Start<\/strong><\/i>  <\/p>\n<p align=\"justify\">When the start button (view D) is depressed, it energizes the solenoid, and the direc&shy; tional valve shifts to direct pump output into the cap end of the cylinder. This causes the check valve in the vent line to close and prevent the relief valve from venting. Pressure again builds up and the cycle is repeated.  <\/p>\n<p align=\"justify\"><a href=\"http:\/\/lh3.googleusercontent.com\/-v8VAHU0iaMU\/VecEw_E4hmI\/AAAAAAAB6l4\/pUpv5FRflOc\/s1600-h\/FLUID-POWER-DYNAMICS-03805.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"FLUID POWER DYNAMICS-0380\" border=\"0\" alt=\"FLUID POWER DYNAMICS-0380\" src=\"http:\/\/lh3.googleusercontent.com\/-uA3Qbrawps4\/VecEzBLsUNI\/AAAAAAAB6mI\/aWdhXRCmoJI\/FLUID-POWER-DYNAMICS-0380_thumb1.jpg?imgmax=800\" width=\"147\" height=\"244\" \/><\/a><a href=\"http:\/\/lh3.googleusercontent.com\/-gyPCdImd5cM\/VecE1FzdvCI\/AAAAAAAB6mY\/JMtukYI07ik\/s1600-h\/FLUID-POWER-DYNAMICS-03815.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"FLUID POWER DYNAMICS-0381\" border=\"0\" alt=\"FLUID POWER DYNAMICS-0381\" src=\"http:\/\/lh3.googleusercontent.com\/-kdH_1wau_Og\/VecE3VPW5PI\/AAAAAAAB6mg\/5mslttwHilI\/FLUID-POWER-DYNAMICS-0381_thumb1.jpg?imgmax=800\" width=\"149\" height=\"244\" \/><\/a>  <\/p>\n<p align=\"justify\">\n<p align=\"justify\"><i><\/i> <\/p>\n<p align=\"justify\">\n","protected":false},"excerpt":{"rendered":"<p>Automatic Venting at End of Cycle In systems where it is not necessary to hold pressure at the end of a cycle, it is possi&shy;ble to unload the pump by automatically venting the relief valve. Figure 9-10 shows such a system using a cam-operated pilot valve to vent the relief valve. Midstroke Extending In view [&hellip;]<br \/><a href=\"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/basic-diagrams-and-systemsautomatic-venting-at-end-of-cycle\/\" class=\"more-link\" >Continue reading&#8230;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/posts\/189"}],"collection":[{"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/comments?post=189"}],"version-history":[{"count":0,"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/posts\/189\/revisions"}],"wp:attachment":[{"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/media?parent=189"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/categories?post=189"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/hydraulics-and-pneumatics\/wp-json\/wp\/v2\/tags?post=189"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}