How to Size a Full Flow PSV/PRV

[MechEng176]

Hi,

I'm working on a job where I'm pumping oil into a pipeline using a positive displacement pump. I need to install a PRV downstream of the pump to kick in at the pipes MOP and divert the product upstream of the pump in an overpressure situation.

When calling the valve people we work with, they just asked me if the fluid was sour, what size (NPT) PRV I wanted, and what is the max pressure. Do I just have to wait until they set the valve to the pressure rating to see what the flow rate would be?




Thanks!

 

[Latexman]

No, don't wait. The PRV must relieve the flow capacity of the PD pump.

Btw, the Safety Relief Valve engineering (PSV) forum may have been a better choice for your post.

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

 

[MechEng176]

Thanks, I'll call them up and make sure they can get me the flow rate I want. When I told them about it first, they were like they don't use flowrate to size the valve. Guess I have to talk to someone who has been there longer.

 

[Latexman]

What they may mean is they expect you to size the PRV and tell them what size you need. That's normally how I do it.

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

 

[LittleInch]

Do the "the valve people we work with" have a website or catalogue? If so then whilst they should be a bit more helpful if they want to seel things to you, you can look this up yourself. When ever I call a vendor I always ask for "technical sales" - you then have more of a chance of getting someone who knows what they're talking about.

Of course you should also complete and issue a data sheet to make sure you get what you want, at which point you give them the data without it being misunderstood and allows for proper review and approval by others in your company as well....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way