Welding Requirements

[macmet]

I work in Canada on hot water systems. These systems are all indoors and isolated from the outdoor conditions. The pipework is also easily accessible throughout the lifetime of the units (well they're supposed to be).

A few people have told me lately that our welding procedures are extremely strict and that there are two common welding standards for hot water systems in Canda. What I'm told is the one we currently request is more appropriate for steam. The problem is that no one seems to know what this other standard is. I'm not even convinced it exists.

I am not too familar with welding standards, but I believe the one we currently request is CSA B51, or ASME B31.1 s-127.5. Can anyone point me to this other welding standard that is apparently more appropriate for our operating conditions?

Our systems are carbon steel pipe, water design temp is 95C. Pressure is less than 100psi. We are using pipe sizes typically between 1.5" and 4".

Let me know what other relevant information may be useful. Our installation costs are extremely high and I'm looking to get out costs down.

 

[macmet]

In an effort to get this thread going, I believe the more lenient standard is ASME B31.9, but I cannot say for sure.

Is anyone familiar with B31.1 and B31.9 and if so, are you able to point me to a good reference comparing the two?

Any help is very much appreciated.

 

[Ron]

B31.9, Building Services Piping, is likely more appropriate to your application.

 

[ColonelSanders83]

I routinley work with B31.1, B31.3, B31.5 and B31.9.

Heres the skinney as far as welding is concerned. All four codes require an ASME section IX weld procedure. No if's and's or but's. The welding procedure for a B31.1 system is the same as the welding procedure for a B31.9 system. Complaints regarding a procedure being to stringent are invalid.

Now, that being said, the accepance criteria for the welds vary substantially code to code. If you have an installation where B31.9 is really applicable (and it sounds like this may be the case) B31.9 acceptance criteria should be used as it has wider tolerance for defects.

Buy your copy here and see if it applies.

http://catalog.asme.org/Codes/PrintBook/B319_Building_Services_Piping.cfm

Just my two cents worth.

A question properly stated is a problem half solved.

Always remember, free advice is worth exactly what you pay for it!

http://www.ap-dynamics.ab.ca/

 

[macmet]

I would like to post some information I've found since posting this question. I think someone in the future who may have a similar question might find this link useful.

http://www.engineeringtoolbox.com/asme-b31pressure-piping-d_39.html