Aged Fire piping hydrotest 1

[Nandaem]

A large high rise apt community in India following IS ( mostly follow British Stds) codes is facing corrosion of 110m high of 3 X 6" CS fire mains filled with untreated bore well water in storage tanks per original flawed design. Its only 2 yrs old.The builder wants to replace corroded portion and hydro test only replaced piping at max operating pressure of 14bar. But owners association wants test at Max OP times 1.5 which is based on ANSI B 31.1.Builder is afraid of risking rupture due to lost thickness if tested at 21bar and defends their position with an IS code that allows retest at OP not 1.5OP. Also cost is an issue as builder has to pay.Appreciate comments and suggestions that could help us resolve the issue. Does any international piping code allow less than 1.5OP for aged installations?

 

[KevinNZ]

What IS code is the builder quoting? They must have copies of the code they designed and built to.

 

[TugboatEng]

The purpose of hydro testing is to prove the system will work and will work for until the next test. If you want to reduce the hydro test pressure I can only suggest you also reduce the hydro test interval.

Also note that a failed hydro test is a successful result as the purpose of the test is to identify defective components.

 

[r6155]

2 years old is like new.
What was wrong?
What is the corrective action so that a new problem does not occur in the next 2 years?

Regards

 

[Nandaem]

Indeed ! We are considering many options among which changing the water source to Municipal supply is one / treat the bore well well water is another

 

[1503-44]

NFPA
The higher of a 200 psig (minimum test pressure), or the working pressure +50 psig

https://blog.qrfs.com/84-what-is-hydrostatic-testing-of-a-buildings-fire-protection-system/

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

What you seem to be talking about is replacement of part of a system with new piping.

This always causes an issue as the new piping needs to be tested to 1.5 times, but then do you test the whole system or not?

There is little in the codes on this and usually some sort of judgement that if the new portion is more than 30% or 50% of the system then re hydro the whole lot. but look up repair or replacement in the original design code and see if it says anything.

If not then I think you should do a "service" test or "leak" test at min 1.1 times the MOP. Basically a compromise between the two.

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

 

[0707]

IMO the system shall be tested according owners association at Max OP times 1.5 which is based on ANSI B 31.1

 

[1503-44]

B31.1 is a bit hard to justify for my taste. Firewater is not even close to being power piping.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[Dhurjati Sen]

The builder gives a pragmatic view. However, he is against the code.
Also, he must have procured poor quality piping hence, does not want to follow the code.
Ask him to submit material test certificates for the piping.
The situation is leading to a legal wrangle unless the builder toes the association line.

DHURJATI SEN
Kolkata, India

 

[EdStainless]

Surely there is an Indian Fire Protection Code similar NFPA.
As 1503-44 pointed out this would lead to a 17bar test pressure.
In any case the test pressure must be above the max system pressure or it doesn't test anything.
My guess is that the builder knows that here will be other failures and he is trying to delay doing what needs to be done.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[TugboatEng]

If you are not confident the pipe will pass a hydro test, a failure of the pipe can be catastrophic to the interior of the building. Consider doing non-destructive testing such as ultrasonic thickness measurement to condemn the pipe before doing a hydro test and prevent expensive damage to the rest of the building.

 

[Nandaem]

Thank you all for your highly valuable inputs ! Since it is fire piping, we can refer NFPA 13/25 which allows hydro testing at Max operating pressure plus 50psi which is 17bar as rightly suggested by 1503-44
The nearest Indian equivalent IS 13039 section 7.1 also calls for 1.5X OP. EdStainless you are spot on !
Durjati, you are right-we are trying to avoid legal wrangle. Hence looking for a compromise which is safe, based on code / best practices.....to the extent possible
Yes, UST is considered ahead of hydro. People are concerned whether the corroded slag or uneven surface of pipe inside will affect accuracy of measurement. I was told US pulse ignores slag..... we will check.
I found the below threads also useful :

https://www.eng-tips.com/viewthread.cfm?qid=415848

&

https://www.eng-tips.com/viewthread.cfm?qid=437187

PS: Can Eng-tips tweak this site to have comments below respective posts ;ile in WhatsApp ?

 

[LittleInch]

The site didn't work like that.

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

 

[TugboatEng]

Ultrasonic measurement does produce accurate results on corroded surfaces. We use it extensively in the maritime industry to detect wasted steel.