Buttwelding Fittings Design Qualification

[Johnrem]

Hi every specialist;

I'm reading ASME B16.9 code and I found in paragraph 9 ''Design Proof Test'' this statement: ''Proof test shall be made when the manufacturer chooses proof testing to qualify the fitting design’’.
That means Manufacturer can choose another method to qualify the design of standardized fittings.
1) Can somebody explain what can be these alternative methods for qualifying the fitting design?
2) Being a client, can we oblige the manufacturer to apply only proof tests not alternative method?

Many thanks

 

[Johnrem]

Please don't forget my thrad....

 

[rneill]

You can use design calculations to validate fitting ratings when suitable design calculations are available.

The client can specify anything he likes with his purchase order. If you want to specify that all fittings shall be qualified based on proof testing, that is up to you. It may incur additional costs if the manufacturer has not previously proof tested them.

 

[Johnrem]

Thank U Rneill;

1) What do you mean by ''if design calculations are available''? Can you confirm that such design calculations are available for tees, elbows and reducers?
2) If your answer to (1) is yes, then I have this second question: Is design calculation based on the actual fitting dimensions or just mathematical formula using fitting's perfect dimensions?

 

[rneill]

I would recommend you read Para 2.2 of ASME B16.9.