Pressure Test

The formula L = NDP^0.5 is somewhat rational, except that it lacks a constant for units conversion/consistency. If I wanted to be really sticky-wicket, I would set this constant (call it K) to zero. But what the hey, we can entertain other numbers..., depending on how toxic/corrosive/valuable the fluid is.

the fluid is WATER

And really i do not know if the test will pass or not with this reducing at pressure

my group had tighten all bolts as they can

Try it and see?

What are the criteria that determine whether the test is a pass or a fail?

that the test of pressure stay at value of 15 bar or may be less ?? but the range i do not know it ??? means does 13.7 bar is approved or not ?

1.- Did you see the leakage?

2.- Flanged valves could be checked? (it is possible to blind limit points?

3.- Wich was the change of temperature during the holding 8 hours?

4.- The 1,3 bars pressure decreasse is to much.

i was drops of water

and i had checked flanged all

temperature is a constant cause we are at pump room

do you know the equation of leakage

No sure, but may be MSS-SP-126- 200 can help.

what is that code ??

do you have a copy of it ?

"The maximun allowed leakeage rate on each seat of metal-seated valves for the duration of the test shall be 4/10 of the standard cubic foot of gas per hour per inch of nominal valve size, or a maximún of 2.44 cubic inches of hidrostatic test media per hour per inch valve size at the test pressure spicified"

Send me one E mail to give you a copy of this MSS-SP- 110

Regards, WP

my email is

and really thank you so much for your support

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OK, not possible, try to find Mss-SP-100, and go to point 7.

May be this way: joecollet88 ya oo. c-m

You guys can send each other personal messages by clicking on each other's name and use the CR4 personal messaging to email each other. It works great!

thank you

we did it ;)

Thanks

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The acceptable leakage rate is determined by the fluid and the local environment. If the working fluid were water at ambient supplied to water a garden, then the leak rate might be acceptable as it wouldn't matter too much. If the fluid were, oh, say a solution of a plutonium nitrate within a nuclear power station, then no leakage would be tolerable.

So there is insufficient information to make a recommendation in this case.

agree with you

but the floor will be wet and that not acceptable ,,

may be if a liter per hour will be acceptable but 8 liters is not ?? right ?

The acceptable leakage rate is still determined by the fluid and the local environment. The latter cannot be seen from here.

ok

thank you for your information

In new piping systems used in oil & gas and designed as per ASME code, no leakage is permitted, the only leakage accepted is in testing of valves as per API. And with test pressure 13.7 bar, the test is considered not passed unless it reach 15 bar as specified by the designer.

So, you are kindly requested to re-tight the stud bolts of flanged connections (as per the recommended procedure) until you reach the specified test pressure without any leakage, and may be you need to use a new gaskets.

dear engr. Abdel halim

Really your massage makes me happy that i found an egyptian here

and i had re-test the pipe after changing the gasket

and take approved :)

Thank you stylee_eng for your compliment.

It is a good sound to hear that you changed the gaskets and retest was passed.

Note. There are a lot of Egyptians here as members of CR4, and I invite yours for registration, see this link: http://cr4.globalspec.com/group/members/5/Egypt.

The "Allowable Leakage" equation that you're using is covered under:

ANSI/AWWA C600-10, AWWA Standard for Installation of Ductile-Iron Mains and Their Appurtenances

(Revision of ANSI/AWWA C600-05). Hydrostatic testing procedures are specifically covered in Section 5.0 of the standard.

You can purchase a copy of the standard at the American Water Works Association (AWWA) website:

www.awwa.org

Also, visit the Ductile Iron Producers Research Association (DIPRA) website for additional information:

www.dipra.org

NOTE: Please bear in mind that you can also take a "leakage allowance" for each closed valve you at hydrostatically testing against.

many thanks for your support