Mss standard compared to astm a860 wphy 52 standard 3

[abdolmaleki1975]

Hello
Can the mss standard replace the astm a860 standard for a 16-inch tee as the base material standard?

 

[1503-44]

I've always specified MSS specs referencing the required yield stress and astm material, however IMO the ASTM material spec need not be mentioned, as long as the MSS spec states the required yield stress. In that case the manufacturer will select the appropriate material to deliver the required strength.

There is certainly nothing wrong with specifying both. ...

36" ELL 90 LR, BE, MSS SP-75 WPHY 60, ASTM A860

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[SJones]

It can, but it needs to be noted that A860 has more stringent requirements for chemical composition and Charpy toughness, for example. Thus, if the stipulated specification is A860, it is not a simple case to blindly replace it with MSS SP-75.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[GD2]

abdolmaleki1975,

What is your question exactly?

Simply put, MSS standard can't replace ASTM A860 standard and are not interchangeable.

The two standards are totally separate with separate scope and intent.
For example MSS-SP-75, is a fitting standard that specifies the design, material, dimensions, Inspection, test, marking etc of the fitting. It doesn't select material but specifies what material properties should be, thereby allowing a bunch of different materials that can comply to its requirements, whereas A860 is an specific ASTM material manufacturing standard that only relates to the manufacturing aspects of the material.

GDD
Canada

 

[abdolmaleki1975]

Dear GD2;
Hello
A seller uses the mss standard instead of the astm standard in his technical offer, claiming that there is no difference other than the difference in the amount of manganese, and demands that we accept his offer.
So my question is clearly whether it is acceptable without mentioning the astm a 860 standard and only with mentioning the mss standard.
It should be noted that I have mentioned both standards in the purchase specifications

 

[abdolmaleki1975]

Dear SJones;
Thank you very much for your kind comment, dear colleague

 

[1503-44]

That is exactly my point.

If you have a valid reason to use the ASTM A860 material, as you have apparently specified, then stay with your specification and demand that the item be made with ASTM A860. If you do not have a valid reason to use only A860, then you are apparently free to consider the alternative materials on offer. Many engineers believe that they must specify the particular material with MSS spec, when in fact only the yield strength should be specified. Usually the only requirement is a particular yield strength and any material that meets that yield strength will do very nicely. If that is the case, you can apparently delete the A860 requirement and accept alternates.

If you do not have a specific reason to use A860, but insist it be provided, then you may be subject to manufacturing delays and extra costs by not allowing the manufacturer to provide alternate materials that he has readily available in stock.




A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[GD2]

abdolmaleki1975,

Can you clearly state what was your purchase specification and what the vendor offered you? We can only help you based on the info you provide.
Manganese is one of the elements in determining the CE. Both MSS and A860 limits the CE to be below <0.42%. I would believe as long as the CE is below the limit specified, you should be fine.

GDD
Canada