PSV on loading rack terminal

[iahmed09]

I have a design for metering skid for loading trucks at a terminal. flow is 500 gpm, with 50 psig and medium is Diesel.
Do I need a PSV if customer P&ID didn't specified it.

Thanks,

 

[BigInch]

What's the line size and velocity of flow?
Many loading applications need a psv, due to fast opening and closing times of valves.

I assume you are the equipment vendor, so you will more than likely be at fault if you think you need a psv, but you don't bring that "oversight" of the failure to include a psv on the PID to the customer's attention.

You could always do a surge analysis to see if you need one or not.


**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[iahmed09]

4" line size with 13 feet per second, with pneumatic butterfly valve as control valves.

I did bring it to the attention to customer about adding, but since now I have two choices only, either to include (2) Kunkle 2x3 PSV staggered with 10% less set pressure downstream than the one at upstream OR go with (1) Crosby 3x4 valve.

I spoke to another expert who has done few of these systems for loading tank truck at terminal, according to him he hasn't included any ever.

I don't have a program or expertise to do surge analysis.

thanks,

 

[dcasto]

Do everything you can to keep from putting on a relief valve. Think about where you will have to relieve to, back to the tank of course, then think about where is the best place, back at the pump. There should be enough compressibility in the diesel that will keep the surge below ANSI 150, if not, go to ANSI 300, it only costs a few bucks more.

 

[BigInch]

If your design is the same as your expert's, you will probably have no troubles.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/