Butt Weld Fitting Questions

You must order materials according to the material you need, not what the supplier wants to send to you. You must know the properties of the base materials you need and be sure that the base materials are supplied accordingly.

Specifications are organized primarily into catagories of

MATERIALS
OBJECT STANDARDS - can be made from various materials
DIMENSIONAL STANDARDS

But some standards overlap a bit, giving both dimensional criteria for flanges and fittings above 24", where ANSI B16 don't go, and actually specify yield strengths required of the worked and treated base materials.

This tender has a number of well organized material requisitions. See pages 5 and 18 for examples

Some typical base materials for WPHY grades 42-70 can be seen on these pdfs here,

**********************
"The problem isn't finding the solution, its trying to get to the real question." BigInch

1. You will receive MSS SP-75 material since that is the specification you appear to be using. It may be feasible to get dual certification as per 3 below.

3. There is no 'MSS SP-75 approval'. Since ASTM A860 is more restrictive than MSS SP-75 in such things as chemical composition, Charpy requirements, and so on, it could be that, on an unamended basis, compliance with ASTM A860 means that materials comply with MSS SP-75 but then there are weldability supplementary requirements that can be invoked in MSS SP-75 but not in A860.



Steve Jones
Materials & Corrosion Engineer

MSS SP-75 is a standard that does specify materials. It is possible and likely that the material will also meet alternative ASTM standards (be dual graded) but not always the case and not necessary unless you specify this.