Hydrotesting

1. depends on the code and what your company has as rule and/or what the customer says

2. no, regular inspections will not avoid the testing if testing is a statuary requirement but you can apply for an exemption and see how you go.

PS what industry is said industry?

You should ask Venus de Milo about statuary repair requirements....

In my time in oil and gas I've never heard of a client accepting inspection with no hydro test. Typically 1.5WP for an FAT the WP for other parts of the FAT/EFAT etc. After repair may be different because you will probably have already done a 1.5WP test at some time in the past so we would fall back on company guidelines, discussion with the client and our own engineering judgement (based on what the damage was and what the repair was).

An example I could give you is a HIPed duplex part which was in a workshop and fell over. It got repaired and came back to the workshop. This had already had all pressure tests done. We concluded full visual, UT, dye pen and a working pressure hydro was what would suffice in that instance. I submitted a formal non conformance report submitted to client which was accepted so job done. I also had meetings with the vendor who did the duplex part so it was a collaboration between me, vendor and client to resolve the issue. Remember, we don't want to expose parts to hydro testing above the working pressure needlessly.

1.-No, never. The test pressure (Hydro, Pnum ....), are not only checks to check welds. Its purpose is to check the behavior and integrity of the system. They are different concepts.

2.- Yes

WP

Question #1 - NO!

Question #2 - NO!

Dear Anonymous Poster #1,

Would you stand next to a pressurised assembly with a gas in it under pressure that had not passed through its burst liability insurance examination and hydraulic test to a greater pressure beforehand?

Yours etc.,

Crabtree.

Hi,

Q1: Is it an underground line? Are you going to have 100% NDT of the entire pipeline/vessel to avoid hydrotesting? This sounds much complex than industry standard/practice.

Q2: You are sure to miss some spots in your regular inspection one or other day and I dont need to explain further on the aftermath. Again, you cannot claim insurance in the evnet of any disaster including Force majure events unless you follow all statutory certifications.

Hope this makes you to go for the hydrotest in the next moment.

Regards,

Srijit

Hi and welcome to the industry, I have scanned some of the answers below and they are wide and varied from Yes to Never. Not very helpful but that is the nature of the beast. I have worked in Oil, Gas and Mining for over 35 years and this is my take on your issues.

Question 1

Yes it is possible to do 100% NDT in lieu of hydro, but this is as a last result only if hydro is totally impractical. Clients and insurers are not keen and I would not rely on it at a design stage of a project. Now that said and some of the other contributors may be interested to know. I am presently working on the Gorgan Gas Project in the North West of Australia and this project has been modulised and module to module hook up ( single weld hook up's SWHU) are full NDT in lieu of hydro. These are joints from 1" to 60" and above.

Question 2

Stat requirements are just that, a stretch of may be available but can not be deleted. This testing is to prove integrity of the vessel after cycling and over pressure over temp condition what have you through the period of use. So in short no.

Hi,

the importance of the hydrotest specialy in the Pressure vessels is to make sure that the equipment have the safty mechanical integrity and welding integrity aganist the MAWP "maximum allowable working pressure" of the equipment. Hence, if the equipment is new fabricate or either in the service and have some kind of repair (major or minor) done on it, it is highly recommneded to do the hydro test according to its constructed code.

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if the vessel was constructed according to ASME VIII Div.1, the API 510 " pressure vessel inspection code" and ASME PCC-2 "post construction code" have the alternatives to the pressure tests and the requirements of the NDE as the following clauses:

API 510 (5.5.8)

ASME PCC-2 (Article 5.2)

another final thing regarding the in service vessels, piping and storage tanks you should make FFS assessment calculation by (API 579) very interseted standard :)

according to the shape and kind of the flaws at the vessel.

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sorry for prelongation, but if it seem like you will like to perform the hydro test in lieu of these calculations and NDEs'. :) :)

Dear Sriji, 3E & Mahmoud,

Thanks for your excellent inputs made me clear on hydro testing