I want to know the method of calculation for selection and sizing of PSV including design of spout

Umesh,

Sizing of PSV depends on various factors or scenarios. You should know if it is for liquid or gas. Crossby's handbook on pressure relief valve and API 520 is good to start with.

Thank You
Jay A&M (2006)

umeshdesh,

Grab and study the following standards and articles and jump start from there :

i) API RP 520 Part I
ii) API RP 520 Part II
iii) API RP 526

There are many articles link in

iii) Useful Documents Related to Pressure Relief Valve (PRV) - Part 1 (included Crosby handbook)
iv) Useful Documents Related to Pressure Relief Valve (PRV) - Part 2
v) Useful Documents Related to Pressure Relief Valve (PRV) - Part 3


Hope this help.

First, this should have been posted in the Relief Devices Forum.

If you are going to get involved in relief systems then you need the proper reference library:

1. API RP520, Latest edition currently 7th Edition, January 2000

2. API Standard 521, Latest edition currently 5th Edition, January 2007

3. ASME Section VIII, Div 1 (or your location's pertinent Codes)

4. "Guidelines for Pressure Relief and Effluent Handling Systems", Center for Chemical Process Safety (CCPS) for the American Institute of Chemical Engineers (AIChE), (1998) New York

5. Fisher, H. G., Forrest, H. S., Grossel, S. S., Huff, J. E., Muller, A. R., Noronha, J. A., Shaw, D. A., and Tilley, B. J. (1992). "Emergency Relief System Design Using DIERS Technology: The DIERS Project Manual. AIChE, New York.

6. Fauske, H. K. "Revisitng DIERS Two-Phase Methodology for Reactive Systems Twenty Years later", Process Safety Progress, (AIChE; Vol. 25, No. 3), September 2006

7. "Easily Size Relief Devices and Piping for Two-Phase Flow", J. Leung, CEP, December 1996

8A. Darby, R., Self, F. E., and Edwards, V. H. "Properly Size Pressure-Relief Valves for Two-Phase flow", Chemical Engineering Magazine, June 2002
8B. Darby, R. "Size Safety-Relief Valves for Any Conditions", Chemical Engineering Magazine, September 2005

9. Simpson, L. L. "Estimate Two-Phase Flow in Safety Devices", Chemical Engineering Magazine, August 1991

10. Ouderkirk, R. "Rigorously Size Relief Valves for Supercritical Fluids", CEP, August 2002

11. Leckner, P. Six Part Series on Rupture Disks, Chemical Engineers' Resourece Page

Various Websites including:
(1) The Chemical Engineers' Resource Page Forum on Pressure Relief Devices
(2) www.fauske.com

Is this extensive? You bet it is! Will you have time to read and understand all of this? NO WaY!!!! I've been doing this stuff for 20 years and still haven't gotten it all down. But I consider these to be MUST HAVES in any library if you are indeed serious about pressure relief system design. If you only are doing this occasionally, then References 1 thru 3 will be good enough as long as there is someone around that has the rest and is over-seeing your work.

There are two parts in this document but have been revised in different month & year.

1a. API RP 520 PI (SIZING & SELECTION) - Ed 7 - Jan 2000 RP Sizing, Selection & Installation of Pressure-Relieving Devices in Refinery

1b. API RP 520 PII (INSTALLATION) - Ed 5 Aug 2003 Sizing, Selection & Installation of Pressure-Relieving Devices in Refinery

I am new to the relief valve world, and have obtained and read several of the sources recommended by pleckner and Joe. I have am having two problems. First, knowing when I actually have a two-phase situation (and which of the omega calcs to use). Can someone point me to a good set of examples that might help. I do have the 1995 and 1998 Symposium documents on order.

Second, the API 520 calcs for below critical conditions / low BP delta P situations require that I know Xo, the quality or vapor mass fraction at stagnation conditions. Is this simply based on the vapor pressure at relief pressure for a single-componenet system? VLE for multi-component?

I am checking RV's in an Ammonia plant. Thanks in advance for any help.

Bill,
Welcome.

I know you question somehow related to the main topic. Your question could be specific to 2-phases relief. If could be a very interesting discussion. I would suggest you open your own new thread for easy searching in future.

Joe, it was not immediately evident to me how to start a new thread. A quick primer on starting new post?

Also, was trying to give some positive feedback to you and pleckner.

You may start a new thread with "NEW TOPIC" button.

If your feedback related to topic of the topic, well...it can always continue in this thread...

Good luck.