ASME B16.9 - factor f for proof test

[bck2ftr]

My query is regarding consideration of factor f as stated in Table 9.3.1-1 of ASM B16.9

One of our supplier submitted proof test records wherein he has used an assembly of two equal tees, two 90 deg elbows and two caps of 4" size 10 mm thickness.

In proof test calculations, he considered factor of 1. I had observed that factor shall be 1.05 if he had used two numbers of geometrically identical fittings.

To this, our supplier's argument is as following:

For the selection of the test factor, we have ensured consistency in the following parameters:
• Same size
• Same wall thickness
• Same material grade
• Same heat lot
Additionally, three or more geometrically similar fittings, manufactured using the same method, were considered. We have conducted three mechanical test specimens accordingly.

Request veterans in the fittings industry to throw light on the above argument.

 

[goutam_freelance]

If two specimens of each type are tested, the factor should be 1.05 as per Table 9.3.1-1. This is to have additional security as the number of specimens is less than 3.

But if the manufacturer has actually performed three or more tests (partly outside your contract) then this may be considered, subject to providing the documents as proof.

 

[bck2ftr]

If two specimens of each type are tested, the factor should be 1.05 as per Table 9.3.1-1. This is to have additional security as the number of specimens is less than 3.

But if the manufacturer has actually performed three or more tests (partly outside your contract) then this may be considered, subject to providing the documents as proof.

@goutam_freelance Our supplier mentioned here that "We have conducted three mechanical test specimens accordingly" .

I understand that when code is saying three or more tests, it is talking about proof tests, and not mechanical tests.

But supplier says that he carried out three tensile tests and considered maximum tensile value for the calculation of Proof test pressure. He submitted the three tensile test reports along with calculations. He has also submitted assembly drawing, wherein two equal tees, two 90 deg elbows and two caps are seen.

And my argument is that he should consider factor f = 1.05 based on two sets of fittings used, and NOT factor f = 1 based on three mechanical tests.

Please correct me.

 

[goutam_freelance]

We have conducted three mechanical test specimens accordingly"

You are right! Three proof tests are required for f=1 (three mechanical tests are not enough).