This article provides information about A number in welding procedure specification based on requirement of ASME Code Section IX.

1. Asme Sfa Numbers
2. Asme Sfa Numbers Chart

A number gives a similar chemical composition in a “as weld”condition. The A number is essential variablein most of welding process in ASME Code Section IX. The Table QW-442 in ASMECode Section IX provides the list of A number. Please note the A number inWPS does not refer to the filler wire or electrodechemical composition; it refers to the deposited weld metal chemical composition.The filler metal and deposited weld metal have different chemical compositions.

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How Do You Determine the A number in Welding ProcedureSpecification?

Asme Sfa Numbers

Asme Sfa Numbers Chart

1. This requirement may be fulfilled by the manufacturer or vendor labeling each container with a statement that the material conforms to the appropriate ASME SFA or AWS specification. If material containers are not labeled, the vendor or manufacturer shall supply a written Certificate of Compliance.
2. Shall be purchased to ASME Section II (SA, SB, SFA) specifications. The ‚Ordering Information’ of the specification (even if it is not mandatory), should be used to prepare a P/O. Requirements of the applicable ‚General Specification’ shall be considered. 4.1 It is the purchaser’s responsibility.

It can be obtained from procedure qualification coupon. The smallpiece of welding can be removed and chemical analysis test to be performed. Thenthe obtained chemical composition must be compared against the table QW-422 andA number to be selected.

Alternatively if your welding process is one of SMAW, GTAW,LBW and PAW processes you may use the filler metal specification or test reportof filler metal manufacturer.

Similarly you can do same assessment for GMAW and EGWprocesses but the shielding gas should be as the same of welding procedure specification.

Again, similarly you can do the same for SAW but the fluxshould be as the same of welding procedure specification.

As mentioned in above, the A number like P number and F number is an essential variablein most welding processes. It means if you have a WPS and you need to use thatin other job with different A number (it means you are using different fillermetal) then you need to re-qualify your WPS because it is essential variable.The A number 1 and 2 are exceptions. You can consider it as nonessentialvariables.

The ASME Section IX Training Course is 2 days video training course and available online and the student that successfully pass the exam, receive I4I academy certificate with 16 hours training credit.

Related Articles:

Group Number, Supplementary Essential Variable, Welding Performance Qualification, Pressure Vessel Inspection

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