Welder Qualification with HDPE electro fusion weld

[thandion]

Good morning,

I have a question regarding welder qualification (performance records) procedures for HDPE pipe electrofusion butt weld. I couldnt find any reference in ASME standards for;

- After welder test, qualified diameters, thickness range
- Qualified materials (I will use HDPE PE 100 SDR 11)
- Which destructive tests should I send to qualify welders

Which standard reference should I follow? (ASTM D3261 maybe?)


Ps. Welders already have certificate that required by the country I am in. All I need is to test them like we do in steel piping.

Thanks&Regards,

 

[metengr]

The ASME B&PV Code, Section IX 2013 publication will have requirements for HDPE pipe welding procedure and performance qualification. For now, I would perform an internet search and try to locate information.

 

[LittleInch]

From your questions you're looking at this from a steel welding point of view. PE is different in many ways from steel and butt fusion (not really welding) is one of those. The best way is use an automatic butt fusion device to do these welds as once you programm in the size, SDR, PE grade etc, it just does it all itself. Manual butt fusion devices need training from the supplier of the machine, but become very operator dependant in terms of quality.

Physical tests, if you really want them, can be to ISO 13593 for pipe butt fusion and 13951 for fittings. Machines are to ISO 12176-1.

Site NDT is very limited and is only a printout from the auto machine or remove the weld bead and test is physical (does it bend without snapping) and then retain the weld bead for each butt fusion.

Look at few vendor websites such as

http://www.fusionprovida.com/products/butt-fusion

Also I've fouind these free downloads very useful in presenting PE technology and instaltions issues -

http://www.gpsuk.com/literature-downloads/

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[thandion]

Thanks for the responses,

The thing is our HDPE welding machine is not automatic (butt fusion type), welder is cutting and heating the surfaces by himself. And our client considers them as a welder not as an operator. I couldnt find anything related to this in internet.

And they want to destructive test on every diameter, which will cost us a lot. If there is a welder qualification standard for HDPE welder, it should include some diameter/thickness range.

Thanks,

 

[LittleInch]

Your client is unfortunatley still in metal welding mode, whereas, as you've discovered, PE works differently. Different sizes and thickness vary the procedure only by the length of time you leave the hot plate on both ends before fusing the two together. The best you're probably going to get is a vendor training course from the fusion machine supplier and a "certicate" at the end of that for the particular person.

Either that or go the fully auto route. Depends how many sizes and welds you've got to do, but could easily be worth it for productivity alone, never mind quality of the weld and traceability / QA if the client is that nervous about this strange PE stuff....

PS - Also look at the testing issue. At test pressure, you often get a pressure decay on PE as it "creeps". This perfectly normal, but can freak out client reps who have only seen steel piping and hence like to see a nice steady pressure. If you keep adding water to maintain a steady presusre, you might end up with a bigger PE pipe than you started with...

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[thandion]

Thanks for the tips, I argued with them about this because our welders already have certificates from third party company about what material or SDR they can weld. I think what they really mean is first production test.

Regards,

 

[LittleInch]

It's their money and time, but I have never heard of it for PE butt fusion. Maybe tell them how much it will cost and how long it takes and then maybe they'll change their mind. The other way is simply to do a test on a scrap piece of pipe and then test to destruction, or 2 x DP. So long as the weld doesn't fail then what are they worried about....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[LittleInch]

Whilst looking for something else I came across the requirements in ASME B 31.3, section A328, which provides for a BPS (Bonding Procedure Specification) which lists required tests, limits on sizes etc. whilst it permits use of a BPS used elsewhere and still seems (IMHO) a bit metal pipe orientated, it does give you something a little better to work to.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[GenB]

You may be looking for fusion pipe mfg instead of ASME PV qualification. There find the required tests. Then certify the pipe to the ASTM specification Or ASME if you get the required certs. Look into A/SA53 Gr F pipe specification. Genblr.