3 Identical interchangeable PSVs on a P&ID dilemma

[Mous1747]

i have 3 Identical interchangeable PSVs on one P&ID, they are installed on the same line ( pump discharge line)
all 3 PSVs have the same size, class and set pressure. they are even the same manufacturer P/N

my problem is those 3 PSV's have 3 different tag numbers/Part number on the P&ID which causing major confusion to the operators and maintenance

my question is would it make more sense to have the same tag number/part number on all 3? to eliminate the confusion

 

[pennpiper]

Are these "Positive Displacement" Pumps?
What is the size of the Pump Discharge Line?
What is the commodity?
What is the Operating Pressure?
What is the Operating Temperature?
What is the set Pressure for the PSV's?
Does each PSV have an Inlet Block Valves?
Where does the PSV Discharge line go?
Does each PSV outlet Line have a Block Valve?
What is the size of the Inlet and Outlet nozzles of the PSV's?


Mous1747, Do you know anything else that might explain this unusual situation?

Sometimes its possible to do all the right things and still get bad results

 

[The Obturator]

My first thought is that these PRV's are installed to operate in parallel to discharge full capacity together. Why? The set pressure most probably could not be obtained with 1 larger PRV, so a series of PRV's capable of the pressure is a solution. Having stated that, they should have staggered set pressures to prevent initial chatter. Then again, some users don't follow (or know) that. As for marking, I would have thought that a simple A/B/C suffix of the same tagg would be appropriate. If more comments can be provided as pennpiper stated along with a data sheet, it may show a more positive answer.

Per ISO, only the term Safety Valve is used regardless of application or design.

 

[mk3223]

First, as avalveman states, the set pressures of three PSVs may need to be staggered. It's clearly each PSV should have its own tag for Engineering aa well as O&M for identification. If there are close to each other, the sequence of the PSVs on P&ID should clearly match PSV locations in the filed for clarity.

 

[MortenA]

Usually you have more than one PSV in parallel for maintenance reasons. But if you cant isolate the individual valves then thats not issue. However, i would not recommend that you give the 3 PSV the same tag no! How will you maintain the service record? I dont know your service but for many PSV you will have to be able to demonstrate that the valve has been tested etc. Also, its not a good idea to retag anything. There will be much old documentation that would need to be updated or would become obsolete.

You operators must learn to be more careful!

Best regards, Morten

PS: The other remarks re. set-p seems correct. Code requires staggerede set-p for parallel service (for capacity).