Golden Welds and Pressure Test
Golden Welds and Pressure Test
(OP)
So I understand the application of Golden Welds. Let's say I am replacing a 10' long damaged segment of 3" ips piping in a 600 psi Liquefied Natural Gas system. There is no feasible way to pressure test the 2 buttwelds required to perform this task. Am I required to separately pressure test the new 10' long piping segment prior to welding into the system? This has been a topic of discussion around the office for the last couple of days, and needs to be put to rest. We have ourselves in a situation similar to the above.





RE: Golden Welds and Pressure Test
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
Mfgenggear
if it can be built it can be calculated.
if it can be calculated it can be built.
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
Out of curiosity, where is the requirement stated ?
B31.3 Cl 345.9.1 states " Welds, including those used in the manufacture of welded pipe and fittings,which have not been subjected to hydrostatic or pneumatic leak tests in accordance with this Code,shall be examined as follows:"..... 100% RT or UT.
So, in accordance with B31.3 if you have ERW pipe you either hydrotest/pneumatic test the section of pipe or you perform 100% NDT on the longitudinal seam.
What if cadiehl has seamless pipe - what are you actually testing ?
IMHO it is a good idea to put caps on the end and pressure test if only to confirm the integrity of the pipe but again IMHO there is no code requirement for it to be performed,
Regards,
Kiwi
RE: Golden Welds and Pressure Test
But now that is unimportant, as codes represent the MINIMUM requirements, it is the engineer's opinion that sets the requirements. Your opinion has already superceeded code minimum requirements and now the system must be tested.... according to YOU, regardless of what is stated in the code, or anywhere else.
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
Your post has absolutely lost me ?
Your initial post stated "It is REQUIRED"
I asked for confirmation of where this requirement is ?
You came back with 345.1 which makes no reference at at all to piping, it talks about piping systems and ensuring "tightness".
Then you have a comment with YOU which completely lost me ?
Cheers,
Kiwi
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: Golden Welds and Pressure Test
Thank you, everyone.
CD
RE: Golden Welds and Pressure Test
flying blind is no excuse, someone there needs to be a qualified engineer.
Mfgenggear
if it can be built it can be calculated.
if it can be calculated it can be built.
RE: Golden Welds and Pressure Test
Mfgenggear
if it can be built it can be calculated.
if it can be calculated it can be built.
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
345.4.2 Test pressure in every point in a metallic piping system shall be as follows:
Not less than 1.5 x design pressure.
Is there any doubt that a piping system includes pipe, fittings and flanges?
I don't think there is any more experienced engineer than Dr. Becht.
Dr. Charles Becht's opinions;
Pressure Testing
ASME B31.3 requires leak testing of all piping systems other than Category D systems. For piping in Category D fluid service, the piping may (at the owner’s option) be put in service without a leak test and examined for leakage during the initial operation of
the system. This is an initial service leak test. For all other piping, the following options are available:
(1) hydrostatic test,
(2) pneumatic test,
(3) hydropneumatic test, and
(4) alternative leak test.
An alternative leak test is only permitted by ASME B31.3 when:
(1) exposure of the piping to water via a hydrostatic test would damage the linings or internal insulation, or contaminate a process that would be hazardous, corrosive, or inoperative
in the presence of moisture; and
(2) a pneumatic test is considered by the owner to entail an unacceptable risk due to the potential release of stored energy in the system (the danger of a pneumatic test ncreases with the pressure and contained volume); or
(3) a hydrostatic test or pneumatic test would present the dan-ger of brittle fracture due to low metal temperature during the test.
Hydrostatic Test
"A hydrostatic test is generally the preferred alternative because it is conducted at a higher pressure, which has beneficial effects such as crack blunting and warm prestressing, and entails sub-stantially less risk than the pneumatic test (alernative). These reduce the risk of crack growth and brittle fracture after the hydrotest when the pipe is placed in service. The test is generally conducted at a pressure of 1.5 times the design pressure times a temperature correction factor.
Closure Welds
In the 1996 edition, addenda c (1998), closure welds were added [para. 345.2.3(c)] as an acceptable exemption from leak testing. A closure weld is a final weld connecting piping system or component that has been successfully leak tested. The closure weld does not require leak testing if it passes 100% radiographic or ultrasonic examination and is in-process examined. Closure welds are not used in the Code in the context of a con-nection to an existing pipe, since that weld is considered to be outside of the scope of ASME B31.3 (although you could look to the closure weld requirements for guidance). Rather, it is a con-nection between new components. For example, consider a large diameter vapor line, for which providing additional support for the fluid weight in a hydrotest is impractical, and for which a pneumatic test would entail undue hazard. The line could be pres-sure tested, as a subassembly, at grade, erected, and connected to equipment with a closure weld. "
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
The above said, with B31.3 the decision ultimately resides with the OWNER of the installation, but at least now WE know how to advise him and that if he thinks differently, he should contact his insurance company and his lawyer.
Note that the pipeline codes B31.4 & 8 differ. Code & USA regulated pipelines must be pressure tested. Fortunately the pipeline codes B31.4 & 8 are specific. The applicable CFRs are law. The owner has no options.
Furthermore, the pipeline codes/CFRs define maximum allowed operating pressure as test_pressure / test_pressure_multiplier, so if not pressure tested, pipelines will not have an operating pressure ... and therefore cannot be operated. A pipeline designed for 1460 psig, but only tested to 1250 psig can only be operated to a maximum pressure of 1250/1.25 = 1000 psig.
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
Just to throw a spanner in the works.
Excerpt below from Dr Becht's commentary states that
"Closure welds are not used in the Code in the context of a con-nection to an existing pipe, since that weld is considered to be outside of the scope of ASME B31.3 (although you could look to the closure weld requirements for guidance). Rather, it is a con-nection between new components."
As cadiehls piping is new connecting to existing it is outside the scope of B31.3 - see also Clause 300 (2).
So what code would it fall under ?
Cheers,
Kiwi
RE: Golden Welds and Pressure Test
IMO ... it is saying that "golden" welds are considered as a connection between two new components, so that even though one component is actually old and would not otherwise be included under the code, a golden weld is.
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
In the example above, pretesting the pipe is meaningless if you have documentation on the pipes process of manufacturing. The weld is the weakest link and a 100% inspection is where the integrety of the piping system is assured. If you apply B31.3 you would only have to xray 10% of the total weld lenght, why do 100%?
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
Pipeline tests are 4 hours minimum and many companies specify 24.
It's not like pipe itself (away from joints) hasn't ever burst during a real hydrotest.
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
If it's welded pipe, they do check the joint, so they are reasonably sure that the welds are OK before testing, so it seems that it is to try to catch those occasional laminations and inclusions that get into the pipe walls... somehow.
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
RE: Golden Welds and Pressure Test
The B31.3 Code requires leak testing for all components. This test does not assess the structural integrity of the components. The Code leak test is performed at pressure levels that do not challenge the ultimate strength required by the Code. In most cases the component is subjected to the leak test after being installed in the field. All components should be reviewed to insure that their pressure/temperature rating is acceptable for the test conditions.
EXAMINATION FOR LEAKS
1) Test personnel shall ensure the hydrostatic pressure is maintained for sufficient time to determine if there are any leaks. A minimum time of 10 minutes is required by Code. After the hydrostatic pressure time has been satisfied, all joints shall examined visually for leaks.
where does it say the pipe must be strenght tested?
RE: Golden Welds and Pressure Test
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
Was waiting to see if you could help me out with an earlier question.
"As cadiehls piping is new connecting to existing it is outside the scope of B31.3 - see also Clause 300 (2).
So what code would it fall under ?
Not trying to be argumentative - even at 51 I still like to learn.
Cl 300 (2) (b) states the code is not intended to be used for piping that has been put in service - so what code would cadiehls piping fall under ?
Regards,
Kiwi
RE: Golden Welds and Pressure Test
... "If you read it (Becht's wording), changing it to a positively framed statement ...
IMO ... it is saying that "golden" welds are considered as a connection between two new components, so that even though one component is actually old and would not otherwise be included under the code, a golden weld is."
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In other words, as I read all of this, his pipe plus the two connecting joint welds are new. He is connecting new pipe to old pipe.
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What I would do personally in this situation is, not worry about the technical details of if only one joint of pipe really needs to be leak tested, or hydrotested, or not. I've seen pipe bust at the center, so I'd just agree with Dr Becht, there's benefits to doing it, there's safety in doing it, so I'd just do it, wash my hands and be done with it, but I'm a die-hard pipeliner and that's what we do ... To paraphrase Robert Frost, "There's (1000) miles to go before I sleep."
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Golden Welds and Pressure Test
Kevin