Strut Valve Specification for New Design 3

[luket]

I want to spec a strut pressure filler valve. The spec numbers I have are AN6287-1 and MS28889L-2. The MS s/s the AN, however, as of 12-1-95, MS28889L is inactive for new design, but no replacement is listed. Can anyone suggest a current, valid replacement?

Thanks for the help.

 

[WKTaylor]

luket...

The part # You need is [SAE] AS28889. Regards, Wil Taylor

 

[i278]

wktaylor,

This is going a little off topic, but your post pretty much ended the point of this thread anyway...

Do you know for how long MS numbers have been superceded with these SAE AS numbers? I'll be the first to admit that I'm not on the forefront of the industry, but AS numbers are a new one on me--I thought all the MS numbers were moving over to NASM equivalents.

I realize that this probably makes no difference in aquiring the parts themselves (what with parts that went MS in 1954 still being ordered by their AN number!), but it may affect where I get future documentation from.

 

[WKTaylor]

i278....

SAE [AS, AMS], AIA [NAS, NASM] and FED-STDs [IE: A-A-xxxx] appear to have divided-up the ANxxxx, ANDxxxxx and MSxxxxx specs.... and many of [but not all] MIL-X-YYYYY specs. This occured during the middle-to-very late 90's.
I am not sure that I fully understand the "logic-pattern" for how these specs were assigned to the various groups for custodial-ship, but here's my guess.

Most materials specs, or materials processing specs, went to SAE as "similar" AMS P/Ns [IE: AMS-QQ-A-250/xx, AMS-S-8802]... or were outright supersceded for equivalent AMSxxxx #s.

Hardware-type Items were reassigned to SAE using ASxxxxx P/Ns that closedly paralleled the original P/Ns... but still retained the "old" ANxxxx/MSxxxxx/etc P/Ns inorder to minimize transition confusion [IE: MS28889 now specified as AS28889.

AIA absorbed Fasteners [Bolts, Nuts, washers, pins, etc] using NASMxxxxx P/Ns that closedly paralleled the original P/Ns... but still retained the "old" ANxxxx/MSxxxxx/MIL-x-yyyyy/etc P/Ns inorder to minimize transition confusion [IE: AN3--AN20 are now specified as NASM3--NASM20].

FED-STDs absorbed and re-identified specialized-tools, maintenance chemicals and materials, etc.

and for good measure....

In some cases the MIL-x-yyyyy specs were retained as MIL-PRF-yyyyy specs.

OH yeah...

MOST (important) MIL-STD-xxxx's were canceled and re-identified as MIL-HDBK-xxxx [or similar #s]... or were supersceded by other industry stds, such as ASTM xyyyyy... but NOT ALL MIL-STDs were canceled.

Yahhhh... enough changes to drive a "gray-haired" engineer to drink!
Regards, Wil Taylor

 

[Kenneth]

Wil, you're right, "specification reform" is a nightmare, and I think you've described a very confusing situation pretty darn well.

One point is worth noting/clarifying.

Re:
"AIA absorbed Fasteners [Bolts, Nuts, washers, pins, etc] using NASMxxxxx P/Ns that closely paralleled the original P/Ns... but still retained the "old" ANxxxx/MSxxxxx/MIL-x-yyyyy/etc P/Ns in order to minimize transition confusion [IE: AN3--AN20 are now specified as NASM3--NASM20]."


The AIA (NASC Committee) has gone to great lengths to carry the identical part numbers forward to "new", replacement "NASM" Standards/Drawings. In general, only the prefix on the Specification/Drawing itself has changed (i.e. The "MS1234" Drawing/Standard "transitioned" to "NASM1234&quot. However this was/is not, in general, carried through to the hardware part numbers on that standard -- which remain exactly the same. (That is, even though the standard/drawing changed from “MS1234” to “NASM1234”, the part number remains exactly the same: “MS1234-1”; not “NASM1234-1”).

I get calls from people thinking that the "NASM" Standard/Drawing prefix automatically applies to the part numbers, and they need to revise hardware part number callouts to reflect this. It is hard for some people to accept that the part number format on the drawing does not necessarily have to reflect the format, or prefix, found on the drawing/standard controlling that part. We're very used to seeing it that way.

However, In the vast majority of cases (perhaps all) for AIA “NASM” Standards, the actual part number (hardware) callouts on the "replacement" drawing are unchanged from what they were on the "original" “MS” drawing. Check the drawing and any associated cancellation/supercession notice.

This is obviously not the case where a government part was “replaced/superceded” by an existing “industry” standard part. These parts, however, will not generally be found on “NASM” prefixed standards. Once again, check the drawing and any associated cancellation/supercession notice.

 

[i278]

That was probably the most concise explanation of a 'shotgun' spec redistribution possible with out the use diagrams. I'm embarrassed to admit that I've made that same MS/NASM part number mistake--it pays to actually read the specs we're referencing!

I guess I generally just work with fasteners; I had no idea the situation was so tangled. Now I think I would've preferred to labour in ignorance.

At least now I have some new places to start looking when I get into that frustrating "but all I want is another screw just like this one" situation! Thank you gentlemen.