Painted cut threads - ASME Pipe Suppliers

[JGH405]

Currently we are asking our pipe suppliers to cut threads deeper on painted pipe. Is this covered on a ASME spec.

 

[japayson]

Look at
ASME
Pipe Threads, General Purpose, Inch
B1.20.1 - 2013

I don't have access, but table of contents lists guidance for coated threads.

 

[JGH405]

Thanks. I will try to get the spec from an Engineer. We have disbanded the Quality Department and I now report to the Manufacturing Manager. No budget for Quality our mandate is support on time delivery for the Value Stream

 

[Miner]

Currently we are asking our pipe suppliers to cut threads deeper on painted pipe. Is this covered on a ASME spec.

Is the pipe painted before or after the threads are cut?

 

[JGH405]

Pipe is painted post threads and then assembled. The theory is make up for the painted threads by cutting them deeper. My stance is the threads are covered by the ASME spec. I found a B1.20.1 -1983 and am trying to get a current spec.

 

[Miner]

I have some experience with e-coated automotive fasteners. In that situation, the customer expected the threads to meet the dimensional specifications after coating, so the threads were cut deeper to allow for the coating thickness. Otherwise the fasteners would not assemble. That may not be as much of an issue with tapered threads.

 

[David-D]

Does the requirement (drawing) state that dimensions are before or after coating/ painting? ASTM Y14.5 on GD&T says yo uh should specify of dimensions are before/after. There are clear reasons to specify one way or the other (strenght, assembly, etc) but if it isnt specified...

Also, are there min/max paint thickness requirements and verifications?

David