Flange 600 test pressure

[johngladstone]

Hi gentelem

I discussed with my friend process engineer
Regarding test pressure of piping network
Its flange is 600

He give me equation
600* 2.4 * 1.5 = 2160

Is this equation is right ?
Is same rule apply for whole flange classes ??

Your valuable feedback is highly appresdiate

Warm regards
John

 

[LittleInch]

John,

You again!

Your friend is not coerect, but as a guide he's not that far away.

I assume you're talking about a class 600 ASME B16.5 flange?

The maximum non shock working pressure of the flange depends on the material and the working temperature. What that pressure is is in tables in asme B16.5, but you can often find the information on the internet or from vendors. It is NOT a fixed value like your friend suggests.

The x1.5 bit comes from the design code. For most process piping that is Asme b31.3 or 31.1.

In that code the test pressure is specified as 1.5 x design pressure. Other codes it can be lower so look at the code.

Many people make the design pressure the same as the maximum pressure the flange can take, but you can choose a lower pressure if you want.

Does that make sense?

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

 

[johngladstone]

Hi littlenech
I always like your valuable
replies .

Is there any guide text attachement pdf to understand pressure part calculations at normal , testing , upnormal situation for upstream oil industry such as pipes , vessels , etc issues to establish alarm limits.. Etc ??

Thank you littlenetch .

Warm regards
John

 

[LittleInch]

There are many guides, but that's too vague a topic.

You need to understand the definitions in the particular design code you have.

So typically for ASME B 31.3, your "normal" or Maximum operating pressure should be less than your design pressure to allow for alarms and trips / relief settings.

If you have a relief valve, typically these are only accurate to about 8-10% below the set point ( design pressure usually). Hence any alarms need to be below that.

B 31.3 allows short term increase in pressure up to 30% above design for a few hours per year ( read the code)

Vessels are different - They have no overpressure allowance as far as I am aware, other than 10% for the relief valves to fully open. But the MAWP is stamped on the vessel plate.

This needs some examples or particular instances.

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

 

[johngladstone]

Thank you littlenetch
I appreciate for your always help