Presser Reducing Valves (PRV)

[buffer72]

Hi all please help me with a question. I am vary much junior to the industry so please bare with me if I am annoying.

I would like to know something about Presser Reducing Valves (PRV). What is or where can I find the criteria or calculations for selecting one?

Sincerely

 

[MortenA]

Buffer

I assume that you mean "pressure" reducing valve. First of all i would like to say that a valve is a valve is a valve.

Some valves are better at just on/off whereas some allow a more gradual opening.

A good control valve is selected based opun many factors. If you are at the side of the table where you buy vlaves then your job is to specify the process parametres (e.g. what is the upstream pressure what downstram pressure). This is a quite broad subject. The Crane Handbook will give you a good introduction to the subject and there are also many other good refernces on the subject printed and on the internet. Try visiting sites from the big manufactors such as TYCO, CRANE, Neles Jamesbury, Mockveld etc. And if your need more info try to talk your boss into giving you a course.

Best regards

Morten

 

[jte]

Buffer -

Are you sure it's a "pressure reducing valve" and not a "pressure relief valve" which you are talking about? Where is this PRV in the system?

jt

 

[JLSeagull]

Self-contained pressure regulators are sometimes called pressure reducing valves or pressure control valves. This is likely the case here. A steam letdown valve could also be a pressure reducing valve.

Search the web for the "Fisher Control Valve Handbook". Someone here may post the link. Fisher is not the only supplier but offers a broad line of control valves and regulators. Fisher also publishes lots of good stuff. You can find them on the web somewhere under Emerson Process - Fisher-Rosemount.

When sizing or selecting any control valve consider the pressure, temperature and materials in addition to the flowing capacity requirements. This is not covered in a single thread but a career. If in the USA obtain some piping standards such as ASME B16.5 to learn about flanges. Other standards apply in the EU countries and Asia.

Do not appologize for being a cub. All of us were cubs once. Most of us are still learning.

 

[Ashereng]

In my neck of the woods, PRV is a pressure regulator (letdown, or back pressure control). Yes, Fisher makes many. I would also like to poin out that their library is really well laid out. Here is a link to regulators:

http://www.spartancontrols.com/library/library_doctree.asp

A pressure control valve, where I am, is usually tagged as a PV (some people also use PCV).

A pressure relief vale, and pressure safety valve, are usually both tagged PSV (PVRV for pressure and vacuum relief valve). Again, this is the convention where I work.

Hope this helps buffer.



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Albert Einstein
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[buffer72]

Thanks for the help all

Many lessons learned

Sincerely