Fitting (weldolet) Material for A106 Gr. C Pipe 1

[gnem]

I'm trying to make a branch connection with the following specifications:

Header - 16 in., Sch. 160, A106 Gr. C
Branch - 4 in., Sch. 160, A106 Gr. C
Design Press. 3210 psig
Design Temp. 490 F
Needs to meet ASME B31.1 Branch Reinforcement Requirements

I'm wondering if anyone knows what type of fitting material (for a 4" weldolet) would have the same properties as A106 Gr. C pipe? I've been told to use A105 material but the mechanical properties aren't quite the same. Can a weldolet be made of A234 Gr. WPC? This material has the same mechanical properties as A106 Gr. C pipe and it is used for butt weld elbows in the same service. However, I've never heard of weldolets being made of A234 Gr. WPC.

Material Properties from ASME B31.1
A106 Gr. C Minimum Tensile = 70000 psi; Minimum Yield = 40000 psi; allowable stress @ 500 F = 20000 psi

A105 Minimum Tensile = 70000 psi; Minimum Yield = 36000 psi; allowable stress @ 500 F = 19600 psi

A234 Gr. WPC Minimum Tensile = 70000 psi; Minimum Yield = 40000; allowable stress @ 500 F = 20000 psi

Please advise.

 

[waskillywabbit]

AFAIK weldolets are SA105 material because they are a forged piece.

Brian

 

[ijzer]

Just use A 105 and in your reinforcement calculation multiply the area of reinforcement in the weldolet with a factor 19600/20000.

 

[BigInch]

Not to discourage curiosity, but this time do what you're told. As waskilly says, forged is the key. Use A105 for your flanges too. Save the 234 for your wrought fittings.

Going the Big Inch!

http://virtualpipeline.spaces.msn.com

 

[gnem]

If I use A105 and don't know which fitting manufacturer will supply the fitting when I'm doing my calcs, then I won't know the area of reinforcement. All the manufacturer's dimensions vary. I contacted a few weldolet manufacturers and was always told that the weldolet will have the same strength as the header material. When I told them that I had A106 Gr. C pipe they said they would use an A105 fitting but agreed that this material is not quite as strong as A106 Gr. C. They are able to supply the weldolet in A234 Gr. WPC and this will have the same properties as the pipe.

 

[GenB]

you can find mats with chrom-molly,
talk to bonnie forge to see if they make it???
genb

 

[BigInch]

This is getting a little too far away from reality now.

Going the Big Inch!

http://virtualpipeline.spaces.msn.com

 

[GenB]

your questions are not so perfect,
just weldolets have build-in reinforcing properties and what you need is to read the Code for your calculations, if you have a comp program will be better (if you can also figure out how to use too),
You need a lot of reading and consulting.

 

[BigInch]

Anybody who is designing new weldolets has too much time on their hands.

Going the Big Inch!

http://virtualpipeline.spaces.msn.com

 

[waskillywabbit]

Make sure you get the flanges you are going to weld on out of A234 Gr. WPC as well.

Brian

 

[gnem]

Flanges have defined pressure ratings at specific temperatures per ASME B16.5, so in this case an A105 flange definitely works. Olet manufacturers will not give pressure ratings for their fittings at specified temps. They just say that they will be as strong or stronger than the header pipe and that they provide the code required reinforcement. So in order to specify the proper weldolet material, one needs to find a material with the same mechanical properties as the header pipe. I didn't ask for any smart remarks, I just wanted to know what fitting material would be a good choice for a weldolet joining two pieces of A106 Gr. C pipe.

 

[BigInch]

The smartest remark was "use A105".

Going the Big Inch!

http://virtualpipeline.spaces.msn.com