Parts of Valve 4" and below from A 479 Bar

[Cleandive]

If a specification states that the valve shall be made from A 182 Tp 316 L forging and if a manufacturer machines the valve components from A 479 SS 316L forged Bar is it OK, the valve is 3" flange rating 600 rating and is dimensioned to B 16.34, API 6D, .

Where as the clause 5.4 The material shall be forged as close as practicable to the specified shape and size. Except for flanges of any type, forged or rolled bar may be used without additional hot working for small cylindrically shaped parts

The manufacturer asserts that as per ASTM A 182 clause 5.4 it is permissble to machine the valve parts from rolled bar without the need for hot working.

Manufacturer claims that the statement in clause "5.4 is for flanges of any type" and not components that has flanged ends?

Does ASTM make such distinction? does the assertion have any merit?

 

[fshnvce]

None of the following standard or specification for valves mandates a particular product form for valve API 6A, API 6D, API 600, API 602, API API 603, B 16.34, ISO 17292

Generally this kind of restrictions to limit the product form creeps into the data sheet of the valve, when the piping engineer when doing the feed or preliminary data sheet includes the product form detail without knowing the consequence.

Notwithstanding the above reason, if you have specified in your specification or data sheet that the valves be made from A182, and if the valve is flanged, and if the manufacturer has machined the valve body that has the flanged portion from A 479 bar, he does not meet the intent of your specification. However, as per the limits that you have set he may supply valve body parts and or any other part from A 479 bar so long as it does not have flanged portion.

The assertion of the manufacturer to justify the use of flanged portion is not correct.

The manufacturer of the valve is taking you on a ride, when the standard says " Except for flanges of any type" this implies, even if an item has flange built in it, despite the fact that the item may be termed as adapter, or body of valve, it does qualify within scope of "any type"

 

[bmoorthy]

While what fshnvce says may be true in some cases, one should not generalize.

Inclusion of a particular product form for valves is not done without knowing the consequences. Some times it is better to have cast or Forged product form as compared to items made from rolled product.While the cast product may have discontinuities, it is good from corrosion point of view. In fact it is even better than forged product in some services (from corrosion point of view). It is also worth noting that cast product form has richer chemistry as compared to forged or rolled product form, in fact, most cast alloys do not even have the same UNS Number as that of other product forms. Hence to assert that while making feed Piping engineers seldom know the consequences of what they write in the data sheet portrays the piping material engineers in dim light, which i think is not justified.

I agree, purely/Literally speaking, the argument made by your vendor has some merit although it is contorted and although it sounds illogical, but there is a way to beat it

If he brings the argument down to definitions, this all comes down to definition of what is a flange, so one has to look at ASTM as to what the definition of flange is
As per ASTM A 961 clause 3.2.4 definition of Flange is "a component for bolted joints used in piping systems".

From the above definition i believe the debate gets settled provided the valve that you ordered is going to be installed in piping system. If you are procuring the valve to be installed on a vessel or on some instrument, and if you had informed this to your vendor, then you to deep further to find reason to counter his argument.