Interpretation Response #PI-73-036
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
D. K. Greenwald, Ladish Company
Henry H. George, Tube Turns, Division of Chemetron Corporation
Robert V. Warrick, Manufacturers Standardization Society
Jean E. Lattan, Taylor Forge Group
SUBJECT: Butt-Welded prototype fittings
These gentlemen came to discuss our letter of August 10, 1973, to Mr. Robert V. Warrick with regard to our clarification of the word "prototype".
They said that the cost for testing each size and type fitting would be enormous. Now they test about 0.2 percent of their fittings and extrapolate test results to cover lines of fittings of many sizes.
They understood that compliance with the last part of the second sentence of paragraph 192.149(b) meant the prototype only had to be tested to a pressure equal to the test pressure for the pipeline to which it is added. (This would mean about 90 percent of SMYS for the pipe.)
They also understood that this was consistent with our letter of November 9, 1970, in comply to their letter of October 30, 1970.
We explained that the first part of the second sentence of paragraph 192.149(b) related to calculated bursting strength of pipe and to clarify the last part of this sentence they could think of the words "calculated bursting" as being ahead of "pressure required for the pipeline to which it is being added."
They pointed out that paragraph 192.505(d)(2) also upheld their argument that the pressure test for the prototype would be at least the pressure required for the pipeline to which the fittings are being added. This would mean 90 percent of SMYS. One of the representatives said that on this basis every fitting has been pressure tested each time the pipeline is tested.
Mr. DeLeon concluded by saying that we understand and appreciate their argument and that we would respond to their letter of August 10, 1973, regarding the interpretation of this section.
Assistant Chief, Tech. Div.