<body><script type="text/javascript"> function setAttributeOnload(object, attribute, val) { if(window.addEventListener) { window.addEventListener('load', function(){ object[attribute] = val; }, false); } else { window.attachEvent('onload', function(){ object[attribute] = val; }); } } </script> <div id="navbar-iframe-container"></div> <script type="text/javascript" src="https://apis.google.com/js/plusone.js"></script> <script type="text/javascript"> gapi.load("gapi.iframes:gapi.iframes.style.bubble", function() { if (gapi.iframes && gapi.iframes.getContext) { gapi.iframes.getContext().openChild({ url: 'https://draft.blogger.com/navbar.g?targetBlogID\x3d8968604820003269863\x26blogName\x3dChemical+%26+Process+Technology\x26publishMode\x3dPUBLISH_MODE_BLOGSPOT\x26navbarType\x3dBLUE\x26layoutType\x3dCLASSIC\x26searchRoot\x3dhttp://webwormcpt.blogspot.com/search\x26blogLocale\x3den\x26v\x3d2\x26homepageUrl\x3dhttp://webwormcpt.blogspot.com/\x26vt\x3d6402931565399164945', where: document.getElementById("navbar-iframe-container"), id: "navbar-iframe" }); } }); </script>

Chemical Process Technology

Continue to learn tips, knowledge and experience about Chemical Process Technology...

Enter your email address:


CLOSE WINDOW


 

Chemical & Process Technology

A place to share knowledge, lesson learnt...

Monday, April 21, 2008

Display problem ? Click HERE

Shutdown Valves (SDV) are commonly use in oil and gas production system for safe and proper isolation purpose to minimize escalation of hazardous from one system to another system.


In "12 Features required for Shutdown Valve (SDV)", one of the requirements of SDV is Fast Action.
A shutdown valve shall act fast to minimize the escalation of hazards. Generally a quarter ball valve is the excellent device in quick action. As rule of thumb, shutdown valve shall be capable of begin it closing action within 10 seconds of activation, and time taken from Full open to Full Close is within 1-2 seconds per inch of shutdown valve size. However, this shall be compliant to overall safety philosophy.


What is the maximum allowable time from shutdown initiation to SDV fully closed ? Any code or standard can be referred ?

According to API RP 14C, 7th Edition, March 2001, "Recommended Practice for Analysis, Design, Installation, and Testing of Basic Surface Safety Systems for Offshore Production Platforms" Appendix C - Support Systems C.2.1.4. "The time it takes for any safety device (e.g. PSH, BSL, ESD station, etc.) to effect component or platform shutdown should not exceed 45 seconds."

Thus, the upper limit is 45 second. However, quick closing SDV would also lead to transient surge. It is recommended the closing time should be minimum 3-5 second. This is just a recommendation. For a piping which is long, low ductility, carrying incompressible fluid, etc, it increases the potential of pipe failure due to surge. A proper surge analysis may be conducted if it is deem necessary.

Related Post:

WebWorm
Continue receive FREE stuff & Update.......Subscribe by Email OR RSS
Any comments / advices ?..........Drop it in comment field (below) or send a private email to me...

Labels: ,

posted by Webworm, 3:21 PM

0 Comments:

Post a Comment

Let us know your opinion !!! You can use some HTML tags, such as  <b>, <i>, <a>

Subscribe to Post Comments [Atom]

Links to this post:

Create a Link

Home:

<< Home