<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://www.blogger.com/navbar.g?targetBlogID\x3d8968604820003269863\x26blogName\x3dChemical+%26+Process+Technology\x26publishMode\x3dPUBLISH_MODE_BLOGSPOT\x26navbarType\x3dBLUE\x26layoutType\x3dCLASSIC\x26searchRoot\x3dhttps://webwormcpt.blogspot.com/search\x26blogLocale\x3den\x26v\x3d2\x26homepageUrl\x3dhttp://webwormcpt.blogspot.com/\x26vt\x3d6505904876529004088', 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:



Chemical & Process Technology

A place to share knowledge, lesson learnt...

Monday, January 28, 2008

Display problem ?
Click HERE

Earlier post “Criteria for Requirement of Pressure Relief Device for Tube Rupture” has discussed the criteria for determination of creditability of tube rupture in heat exchanger. For a particular scenario where a Pressure Relief Device (PRD) is required to protect a heat exchanger from tube rupture, there is still issue on the type of PRD to be used.

It is always recommended to provide a Pressure Relief Valve (PRV) to minimize inventory lost to flare and drain disposal system. For a heat exchanger with gas in low design pressure (LPS) side, whenever tube rupture occurred, the gas may provide some “cushion” effect to minimize surge pressure. Thus, a pressure relief valve (PSV) is acceptable in this case.

However, in the event liquid in LPS side, sudden tube rupture may generate a huge surge pressure to the LPS within a mili-second and results the intermittent peak pressure exceeded design pressure of LPS, pressure relief valve (PRV) is NOT recommended in this case. Pressure relief valve is known to be a “slow acting device”, it may NOT response fast enough to relieve pressure. Thus, a rupture disk which known as “quick acting device” is always recommended in this case.

Nevertheless, there are some researches carried out by HSE UK and reported that there are rupture disks may NOT open quick enough as compare to the surge pressure built-up. Details may refer to :

Per API STD 521 (2007), section 5.19.3, one-dimensional dynamic modeling / analysis is recommended where there is a wide difference in design pressure between HPS and LPS (e.g. 70 barg and above). A one-dimensional dynamic model is to simulate the pressure profile and pressure transients developed in the exchanger from the time of the rupture which includes tube-rupture fluid dynamic and Pressure relief device response.

Related Topic

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, 1:00 PM


Post a Comment

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

Subscribe to Post Comments [Atom]


<< Home