API 650 / Want to Change a Flange 2

[Abdolrahimi]

Hello Everyone
We want to change just a shell nozzle flange after hydrostatic test.
Can we do it without any subsequent hydrotest?
Our tank is made with the requirements of API650

 

[IFRs]

This does not seem to be mentioned in API 650, at least from my quick search. However, I would personally have no problem with it because the purpose of the hydrostatic test is to strength-test the shell and load the foundation (See 7.3.6), and as long as the nozzle in question is not a flush-type and the flange-to-neck weld is outside of the zone that contributes to reinforcement of the opening I don't see how it affects the hydrotest. My opinion only and you read it on the World Wild Web.

 

[LittleInch]

Drawing or sketch would help a lot.

But I agree with IFRS, this is really a piping thing not a tank thing unless the flange is part of the tank. Hence a drawing needed.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

"Shell nozzle" suggests it is on the tank.

 

[LittleInch]

It's quite a vague description which could mean different things to different people. A drawing would define it much better.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Abdolrahimi]

Dear IFRs & LittleInch
Thanks for your guides
We experimentally decided to "Service Test" the tank that contains just water.
But someone had a better opinion: Partial Test of the nozzle; however he didn't render any references.

 

[MJCronin]

Is this change necessary to meet some type of contract/ drawing requirement or is this a real problem ?

Explain specifically: The existing tank flange is "X" .... and we need "Y"

Can you change the flange with a short piping pup piece with different types of flanges on each end of the pup ?

By "change just a shell nozzle flange" do you really mean make the nozzle larger or smaller in diameter ???..... or are you not telling us ?.... Do you have an MBA ???

As always, graybeards on these fora need sketches, more details, materials, etc...etc etc

MJCronin
Sr. Process Engineer

 

[Abdolrahimi]

Dear MJCronin
Class of the flange changed from 150 to 300 pound, because of a change in the instrument that connect to the flange