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Hydotest Prior to NDE
2

Hydotest Prior to NDE

Hydotest Prior to NDE

(OP)
Hi,

Anyone got experience doing hydrotest prior to NDE? Was informed this is violation of ASME B31.3.

In order to expedite the project, we plan to do hydrotest prior to NDE on selected services and pipe class.

Thanks

ppm

RE: Hydotest Prior to NDE

2
Well, I'd say its a little more than a violation,
its a FLAGRANT violation.

**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

Besides being a violation of Code, what would happen if you found defective welds (almost a certainty) and they had to be repaired? You would be required to hydrotest after making the repairs - not too expeditious!!  

RE: Hydotest Prior to NDE

I've really just got to say if I saw that proposal, I'd immediately go for the shotgun.

**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

As stated by many others, this is a major code violation. Essentially, not to put to fine a point on it, you could potentially be sacrificing safety for the sake of expediency in accelerating the project schedule.

RE: Hydotest Prior to NDE

(OP)
Depending on the service and pipe class, NDE may not be 100%, sometime only 5% or 10% prior to doing hydrotest. I presume this risk is also allowed by code?

RE: Hydotest Prior to NDE

Well, if its only 10%, then do it before hydrotest.
Remember that a 10% rate is a spot check and, if you happened to find 1 bad one, that 10% would be increased, so that increased percentage would have to come before hydrotest too.  

How do you think you're going to do 10% after hydrotest anyway?

**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

Look at the danger involved:  NDE is there BECAUSE some welds fail.   

(Not many of "mine" of course! - well, the ones that my crews actually so - but over time you will lose a certain number of welds.  So, what are going to do when (not if, but when) a weld or joint fails during the hydro test and you break parts of steel off into somebody's head, neck, or torso?)

RE: Hydotest Prior to NDE

I have a question about this.  I think that B31.3 allows for a hydrotest in lieu of NDE.  However, as you get to it depends on the situation whether this is wise or not.  If you were doing a relatively low pressure application with extremely low likelihood of failure on a piping system (low cost) where failure would likely result in little to no appreciable action, then why would a hydrostatic test not be done in lieu of an Xray or other test?   

RE: Hydotest Prior to NDE

The OP's question implied he had NDE requirements that he should have been putting before hydro, so we all assumed welding was the method he would use to make the joints.

The only escape clause I know of is, if you are NOT doing any welding, brazing on any joints in the system and of course not working with elevated temperatures or high cyclic stress, etc.  If you are clamping, or screwing pipe together or somehow otherwise making joints that require no welding and brazing, then only a leak test is required; see paragraph 345.  If that's the case, no NDE is required at all, so do the leak test before you do any NDE smile

If you had a piping system with such a low probability of failure as you describe (welded or not) and that little a chance of doing damage, or causing harm to persons, company, or property and repair cost would be insignificant, then why worry about any testing at all because its doubtful that your piping would be covered by any code or regulation anyway.  So if no code or requlation applies and the engineering specs don't specify NDE and, if the owner agrees with you, go for it.

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

Hydro test is a form of Non Destructive Examination.  Also, NDE covers the gammut from UT to RT to Dype Pen testing.  So my question to the OP is - what NDE is required on your system?  If it is RT or LPT or UT of the welds, then it must be done prior to hydro.

RE: Hydotest Prior to NDE

like a weld test.

  

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

BigInch,
Good one! We used to have at least one pipe blow up during hydrotest of new gas pipe line installations when pipe was shipped by rail - so much for the nondestructive part of hydrotesting.  

RE: Hydotest Prior to NDE

remember under B31.3, there is no strenght test, only a leak test.  B31.8 has a strenght test.

RE: Hydotest Prior to NDE

Hydrotest is NDE only when luck is on your side.
That's a vessel ... strength test.

Something about steel wheels rolling on rails.  Every crossing of an expansion joint must go straight to the pipe.

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

Reminder:  

The NDE and Pressure Vessel Code was written with (somebody else's) blood.   

 

RE: Hydotest Prior to NDE

so far anyway.

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

What is NDE?

"We don't believe things because they are true, things are true because we believe them."

RE: Hydotest Prior to NDE

Not Do Enything

Just kidding.  

Really, its kind of like Non-Destructive Testing, but some people think that if you only look at it, or don't actually perform a "test", then it should just be called "Examination".  Non-destructive Examination.

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

I see NDE and NDT used interchangeably. To my mind (maybe not the best reference point) NDE includes performing the actual test as well, otherwise how can you examine it?.

Cheers,
John

RE: Hydotest Prior to NDE

Ya. That was my point too.  IMO, its been called simply NDT up to very recent time.  At least I haven't seen NDE before last year or so.  Wonder where NDE came from?  Somebody wanted to distinguish "eyeballing" examination from an actual test I suppose.

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

does one 'examine' an x-ray or does one 'test' an x-ray. I reckon one 'examines'

RE: Hydotest Prior to NDE

Does one examine an X-ray, or examine the pipe by taking an X-ray.  Is a "test" only a test when something is broken in the process, or can test mean any "evaluation".  Is it an examination, or an evaluation that is really the object of the exercise.  Perhaps NDE really means Non Destructive "Evaluation"???

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/

RE: Hydotest Prior to NDE

I just had a random look in ASME VIII, and in UG-90 there is mention of "provision of records of nondestructive testing examinations performed....". Maybe we should therefore abbreviate it to NDTE to avoid confusion in some peoples minds? (Or NTE following this ASME example.)

RE: Hydotest Prior to NDE

Good idea.  Now that you mention it, NDTE was at one time pretty common as well.  3 letters is easier than 4 on the iPod perhaps.  In any case, all of them mean pretty much the same practically speaking.  Just goes to show how good we can be at splitting hairs sometimes.

**********************
"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/

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