QQ-P-35, type 11 vs QQ-P-35C, type 11

[daxmann]

Does anyone know the difference between passivate per QQ-P-35, type 11 verses passivate per QQ-P-35C, type 11? Some of the parts came in looking kind of a gray-black and others the standard silver. I have done some research and found that the specs have been updated and cancelled and updated and cancelled again but I guess I'm just needing to know if the parts are still usable. Thanks for the help.

 

[WKTaylor]

daxmann...

QQ-P-35A [1968] Lists Type I, II and III...
Type I Low Temperature.
Type II Medium Temperature.
Type III High Temperature
NOTE. Subsequent revisions added more roman numerals for specific passivation treatments for various SSTL [CRES] and HRA materials.

Perhaps what appears to be Type 11 is actually Type II???

I actually prefer to specify AMS2700 Method 2 - Passivation in Citric Acid ... which is applicable to virtually all SSTL/HRA metals...and is "eco-green" for storage/waste disposal.

Regards, Wil Taylor

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o We believe to be true what we prefer to be true.
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o Unfortunately, in science what You 'believe' is irrelevant. ["Orion"]
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[tbuelna]

If your PO specified QQ-P-35, type 11, which as wktaylor noted is a process that doesn't exist, where did you find a vendor to perform this work? Even though QQ-P-35 is no longer current or used for new design, there are still vendors qualified to perform the process for legacy applications. As for the difference between QQ-P-35 and QQ-P-35C, the vendor should use the latest spec revision unless otherwise instructed.

If your PO specified passivation per QQ-P-35 type II, use of this obsolete process is acceptable for your application, you have a vendor qualified to perform this process, and the vendor supplies a CoC and/or certs stating they performed the work in accordance with the standard, then you can probably go ahead and use the parts.