Pressure ratings of butt-weld fittings

[zakk]

We are designing pig receivers utilizing wrought butt-weld fittings (Reducing Tees manufactured to ASME B16.9). Would anyone know where I can find pressure/temperature ratings or burst pressure for these fittings? They are not found in B16.9.

 

[1969grad]

Pressure-temperature ratings are the same as the mating pipe.

Pig receivers should be designed as fabricated piping assemblies per B31.4 or B31.8 (or the DOT code) as applicable. Receivers are part of the pipeline so if they are in a B31.3 facility then the code break is downstream.

Forget burst pressure as you will not be anywhere near the ultimate tensile strength. The above codes limit the max operating pressure to below the yield strength.

 

[bvi]

I don't know why you would need burst pressure (see 1969grad answer), but if you need it for some reason, it should be about three times the burst pressure of matching straight seamless pipe. This is not something normally used in design.