How to define the PSL, PR and material class for HP fittings, valves, pipes etc

[g30rg3]

Quick question, could someone give some light how to define the PSL, PR and material class for HP fittings, valves, pipes etc.

For PSL level I currently use the flowchart in API 6 A.( Figure A.14 — Recommended minimum PSL for primary parts of wellhead and christmas tree equipment) again this is for wellhead and christmas tree equipment. Am I doing the right thing? Design perspective its always better to design on the higher side, just wanted to know what is actually required.

Thank you for your time.

 

[jbeckhou]

Are you a seller or buyer?

Petrotrim Services, LLC

http://www.petrotrim.com

 

[g30rg3]

A buyer.
Working as a piping engineer, while placing an order would like to know the basic minimum requirements which should be specified.

This pertains HP mud, cement & the choke & kill systems.

 

[jaydeep29]

Customer should define working pressure and temperature class.
From that we can follow API 6A for material selection.

Rest material selection follow ASME B16.34.

My Motto: Keep calm and never give up.

 

[Gilmiril]

"Design perspective its always better to design on the higher side, just wanted to know what is actually required."

That's true if there's ambiguity. Ultimately, the best design is that which meets the client's specification at the best price. Designing "on the higher side" means designing product that exceeds the client's specification, which almost always increases the price, so the question becomes, "Is it worth it?"

API 6A is a specification (not a standard), so it a system for specifying equipment. But it's left to the client to specify what they want/need. The flow chart for determining PSL is a good starting point, and I would suggest never going with a higher PSL than that chart recommends unless you have a very good reason/need to do so (every time we've ever been asked for PSL4, it's been a mistake by a junior engineer).

The biggest challenge is probably material class. It's easy to decide on whether or not NACE compliance is required, but beyond that, it becomes a cost/benefit analysis. Material classes DD, EE, FF, and HH are all suitable for sour service, but each one is progressively more expensive, so you have to know your application and decide what level is really needed.

I know this isn't much help.

 

[jaydeep29]

All design term base work on pressure and temperature class.What kind a service you want to apply?
In API 6A wellhead & Christmas tree equipment as well Choke and kill API 16C standards.
Here PLS1,2,3,3G & 4 shows product specification level.
And PR1,PR2 show products performance level.
TIP:-If you go higher level that contain all lower criteria as well.

My Motto: Keep calm and never give up.

 

[g30rg3]

Thanks guys again for your time.

Yes i am aware that a higher spec is always better and safe. (by default meets the lower spec requirement)

like Gilmiril mentioned "Is it worth it? "
From a basic design perspective this is the something that can drill you down.

If i were to design the system for 15K /10k/5k psi & temp class PU (STD/sour service), what would be the PSL, PR and material class? The flowchart can be my guide Figure A.14 for PSL level ?

I work for firm that builds rigs and often reached a wall as to what to order when the client has not specified any spec for their systems. (hence the question) Yes like any junior level engineer i've been requesting for piping & related components on the higher side to save burns.

So what would be the actual requirement still remains a mystery.

veneeth george
piping engineer - offshore rigs