Pipe Pressure Test Failure
Pipe Pressure Test Failure
(OP)
A portion of 8" dia pipe failed a pressure test. Failure was along the longitudinal welded seam. It is my understanding that ASTM does not permit welding within an 1" of the seam. Is this correct? and is it possible under some other regulation that the seam, with a proper welding procedure, can be rewelded to repair the damage.
Dik
Dik





RE: Pipe Pressure Test Failure
I have not heard of the 1" seam rule, but am aware of branch connections through seams, which are allowed - however there are also specific provisions in the ASTM (ASME) specifications that provide for repair welding for certification (approved by the purchaser, of course) With general reference to A-530.
RE: Pipe Pressure Test Failure
Is this new pipe or has in been inservice?
RE: Pipe Pressure Test Failure
I have never heard of an ERW seam failing in a test (these seams are prone to MIC and other types of cathodic corrosion when they are standing in water, but that failure is always some time after the test). I've had hydrotest failures, but never at the seam or at a girth weld. I would get the mill data on the pipe and trace back to why a bullet proof weld failed. This had to be a manufacturing defect that could have affected the entire mill run.
David
RE: Pipe Pressure Test Failure
Dik
RE: Pipe Pressure Test Failure
RE: Pipe Pressure Test Failure
I would recommend that somebody check the design before re-testing and make sure the pipe wall is thick enough for the application.
Also I would be in contact with the pipe supplier particulary if the pipe failed at a pressure it should have withstood.
I know that in some pressure vessel specifications that some welds are restricted as to how close they can be to a main seam weld but I am not familiar with ASTM
desertfox
RE: Pipe Pressure Test Failure
You are sure it wasn't made of bubblegum?
Greetings
RE: Pipe Pressure Test Failure
How long is the failure?
What is the ASTM designation of this pipe?
RE: Pipe Pressure Test Failure
The 1"-rule makes no sense. ERW pipe can and is routinely welded...wherever necessary for the connections.
There is a 1" proximity reduction in allowable stress for welded aluminum, but not carbon steel.
RE: Pipe Pressure Test Failure
RE: Pipe Pressure Test Failure
ASTM A53, states:
12.2.2 Type S pipe and the parent metal of Type E pipe, except within 1⁄2 in. [13 mm] of the fusion line of the electric-resistance-weld seam, are permitted to be repaired in accordance with the welding provisions of 12.5. Repair welding of Type F pipe and the weld seam of Type E pipe is prohibited.
RE: Pipe Pressure Test Failure
Dik
RE: Pipe Pressure Test Failure
8" Sch. 40 Grade A: 1340 psi !!!!!!
Grade B: 1570 psi !!!!!!
10" Sch 40 Grade A: 1220 psi !!!!!!
Grade B: 1430 psi !!!!!2
I don't have access to the ASTM standards right now, but I am looking at the ASME SA-53, which is identical to the ASTM except for insertion of test practices in 11.1.1 and editorial correction to Table X4.1
And there is no mention of the clause you have stated , in fact - it states "14.5 Weld repair shall be permitted only subject to approval of the purchaser and in accordance with Specification A 530/A 530M."
RE: Pipe Pressure Test Failure
I would not attempt to repair the weld but put in a new spool piece where the failures were.
I would seek some compensation from manufacturer.
RE: Pipe Pressure Test Failure
Can you get pictures and post them...???
They might be very informative and enable you ( and us) to learn more...
"brimmer" is spot on...... you have been sold un-inspected Chinese "crap pipe" and deserve compensation.
Now ... lets all repeat that new millenia business mantra:
"freemarkets....freemarkets....freemarkets...freemarkets.."
This fine forum has many other previous posts about defective Chinese piping, pressure vessels and components.
-MJC
RE: Pipe Pressure Test Failure
I don't know where the actual failure was, but was in the same line as the ERW joint. See note to MJC
MJC:
No pix... the pipe was re-welded prior to us being informed.
AllHandlesTaken:
My quote from A53 was a direct 'cut and paste'; if you cannot locate this, has this been changed?
RE: Pipe Pressure Test Failure
Like I mentioned I was looking at the ASME SA-53; 2007 ed.
What year is the ASTM spec that you are looking at?
RE: Pipe Pressure Test Failure
Regardless, I would still replace it all with different QUALITY pipe and take it up with your purchaser's/supplier.
RE: Pipe Pressure Test Failure
I will have to check the ASTM standard later for that clause (or just take your word for it).
I see you've caught my posts before... if I don't like a standard... I make one up and give it a number <G>.
Dik
RE: Pipe Pressure Test Failure
There are several runs of several hundred feet of the material already installed. The work was almost finished and failed the pressure testing part of the specification. The structure is enclosed and it would be difficult (not impossible) for the pipes to be removed and replaced.
RE: Pipe Pressure Test Failure
Radiography would work, but would be expensive.
RE: Pipe Pressure Test Failure
Dik
RE: Pipe Pressure Test Failure
you might be able to test with internal ultrasonic tool, should detect these types of defects, I don't know what your scenario is
RE: Pipe Pressure Test Failure
Rip it out - DEMAND your money back.
Look - pipe that is failing at 80 psi is tissue paper.
On an offshore rig, are YOU going to live UNDER it 24/7 for 30 years with anything "important" or flamable inside? Tell that rig's crew what happened: See how of them stay on board.
RE: Pipe Pressure Test Failure
That was my original thought, but there is a lot of it installed and it is difficult to remove and re-install and I was wondering if there was another solution.
Dik
RE: Pipe Pressure Test Failure
Regards BrianC
RE: Pipe Pressure Test Failure
Dik
RE: Pipe Pressure Test Failure
Consider that a single R/T of a circum. weld takes 1 hr setup (in a powerplant at least) and an exclusion area of around 100 ft radius. 45-75 some-odd minutes per weld (36 inch circle) then 1/2 hour take down time. Move to the next weld, repeat.
Now image that much time for a linear distance of "several hundred feet". The R/T might work if it (the souorce) were dragged down the inside of the pipe with the film tapes continuously to the outside over the weld. But you'd need calibration points on the pipe and film to track down defect locations. Add thousands more dollars for exam time, rip out and replacement of the bad/suspect pipe anyway. Scaffolding. Insulation takeut, hangers in the way of the exams.
Worse: he has had catastrophic failure at low pressure in one pipe. How many other pipes from that supplier has he got installed? The supplier is overseas, behind a protective (and corrupt) local and national government. Replacement pipe is expensive, but imagine trying to collect billions to pay for the burned out rig PLUS medical liability claims for the killed workers.
Faced with that bill, the Chinese company will likely simply "disappear" - nobody will be be there to be liable.
1) UT/MT might show extent of what pipe needs to be replaced.
2) Get the repair records of what was re-welded. DON'T trust the re-welded pipe.
RE: Pipe Pressure Test Failure
Whatever you decide to do further inspection will be required and the results past up the chain to ensure root cause and corrective action.
Regards Brian
RE: Pipe Pressure Test Failure
ASTM A53, states:
12.2.2 Type S pipe and the parent metal of Type E pipe, except within 1⁄2 in. [13 mm] of the fusion line of the electric-resistance-weld seam, are permitted to be repaired in accordance with the welding provisions of 12.5. Repair welding of Type F pipe and the weld seam of Type E pipe is prohibited.
is there any means of re-welding to effect a repair? 'Prohibited' seems to be a pretty strong word.
Dik
RE: Pipe Pressure Test Failure
RE: Pipe Pressure Test Failure
It might well be that a repair can be justified pwht.
I take it you have found no more defective pipe on your or other projects and the supplier has had no other reports of similar failures?
Regards Brian
RE: Pipe Pressure Test Failure
One run of pipe was tested during one hydro test: That run failed at only 80 psig.
"Somebody" weld-repaired that (one run) of pipe at that failed location: so he had to heat up the failed (burst out and deformed) section and beat it back into a "sort of round" shape in order to get the original edges back near enough together to weld them manually. So now you have a heat-affected (low strength) zone around the weld, a low strength (yellow-or-dull red-heat) "manually forged" section and an out-of-round (stress -induced failure) section AND a retest-required weld that must be itself tested at full hydro pressure.
BUT, the rest of the pipe has NEVER been tested to anything past 80 psig: the original failure point of the first pressure test. Why do you assume that the rest of the pipe will even get up to 100 psig, much less 120, 140, or full hydro pressure. (As noted above it "should" have passed the 1250 pressure test at the factory - but we know that it could not have.)
RE: Pipe Pressure Test Failure
As a minimum, I recommend removal and replacement of the burst pipes and perform the A-53 required tests thereon. Welds should additionally be examined using magnetic flux leakage and UT methods.
RE: Pipe Pressure Test Failure
So,
1) Remove the pipe that has burst. Unbolt the flanges and fittings (it will be less expensive than rebiulding the pieces). Pull it out of the racks and overheads and put the pieces 9each spool) on the deck. Put blanks on each section - leave the long welded sections in the rack only if you have too. Hydro each section. As more and more break - if they break - demand your money back plus damages plus cost of testing plus delay time.
2) Use the separated spools as templates for the replacement sections: Weld brackets (dead or dummy flanges temporarily attached to the deck or brackets) at each flanged end of each spool. From each of these dead flanges, rebuild the replacement spools back towards the template at the other end - that way, the replacement spools will fit the original location with little problem.
As you find out how many spool sections are breaking, you can begin to identify the limits of your problem. Use NDE properly: to verify the fabrication welds at fittings and flanges, not to check the full length resistance welds down every length of pipe. Field NDE isn't accurate enough to do that job. Field welding isn't accurate enough (economical enough and fast enough) to rebuild pipe lengthwise welds.
Right now, all you have is a deathtrap of unknown pressure rating.
RE: Pipe Pressure Test Failure
----------- Start of Quote -----------
"...Joint 001 welded by 'Welder A' failed the radiograph. Joints 002 and 003 the (sic) films were not able to be used. These joints are required to be re-tested.
Testing Co has reviewed all of the three pipes that, the weld seam has cracked (6" pipe that had visually bad seam - V groove; this one also offshore but from India). It is our recommendation that samples of these pipes be sent for Chemical and Mechanical testing to verify that they meet the requirements of ASTM A53 standard for pipe grade B.
The Client has requested that Testing Co perform ultrasonic inspection to the piping throughout the Project, to insure the pipe weld joint is sound. Testing Co has requested pipe samples several times from the contractor, for calibration purposes.
Once we have these samples from the different nominal pipe diameters we can begin the random spot checks of the heat numbers that have failed the hydrostatic testing as will (sic) as some additional testing of other piping that has passed the hydrostatic testing..."
----------- End of Quote -----------
It seems to be moving slowly... and will keep you posted on the end results. I haven't been involved with this, but it seems that there is some difficulty in obtaining samples from the contractor. Some of the pipes carry water at about 160F while others have cold water.
RE: Pipe Pressure Test Failure
Keith Cress
kcress - http://www.flaminsystems.com
RE: Pipe Pressure Test Failure
UT could show "depth" problems inside a deep piece of metal, but not across a seam that thin. (Pipe wall is less than 1/2 thick.)
RE: Pipe Pressure Test Failure
Dik
RE: Pipe Pressure Test Failure
I know ive come to this late, but yeah id have gottent eh lawyers involved a long time ago, replace all the pipe that came from that supplier.
Ive worked in Offshore and i know the kind of service life that is expected in alot of this stuff, and the usual quality standrds, this pipe ahs failed miserably. the sad thing is no matter how this works out its a lose lose situation, your losing fab time, its going to cost you money to rebuild it all and to source new pipe, things are bad all around really.
RE: Pipe Pressure Test Failure
This is an interesting thread, and I think everyone here can empathize with your situation. One encounters such ethical-economic dilemmas in the supposedly objective world of engineering with surprising frequency.
That being said, I find myself agreeing to most of the statements made by racookpe1978. Would like to hear more as the situation evolves, and wish you the best.
RE: Pipe Pressure Test Failure
What was the outcome of the pipe in question
RE: Pipe Pressure Test Failure
Dik
RE: Pipe Pressure Test Failure
We have had several hydrotest failures in CS piping over the years and If I recall correctly all were of the ERW variety slated for use in non hazardous service. We did have inservice failure of 10" Sch 80 welded pipe from fatigue, thermal, in 75 psig steam service. The origin of the failure was an area of LOF and LOP in the seam weld. All our failures were in domestic made pipe.
The same problem is found in SS piping. Take a look at the following thread to see what you can run into with such a failure. Since this thread was posted two other sticks of SS pipe, one SCH 40 and one SCH 80 have been found to contain LOF defects by the pipe fitters while prepping for welding. These pipe were by two different manufacturers. I don't have the spec for the pipe. This has resulted in the requirement that all end preps on SS pipe are to be PT tested..
thread378-70822: Stainless Steel Pipe
The reference URL in the above thread has changed to the one below.
htt
In my previous post I mentioned that the same problem had occurred at Vandenberg Air Force Base and I have sense learned that the same problem was found at the NASA Site in Mississippi except on a larger scale. I have heard that NASA wasn't very happy about the problem.
RE: Pipe Pressure Test Failure