tig nozzle diameter 8

[sixxerxxre]

is there anyone knowing about TIG welding ceramic nozzles diameter parameter ?
what is the result if the welder changes the diameter from 10 mm in WPS to 12 mm or more ? or 9 mm and less ?
is it possible to qualify a TIG weld without recording this parameter ?
thanking you
serge

 

[DekDee]

tbuelna,
You are correct - the welder must follow the WPS.
But, and this is a big but - the person writing the WPS must use common sense.
PQR's record actual, WPS's (are supposed to) give a range for the welder to work within.
Listing a single cup size on the WPS and then classifying welds as non-conforming because a different cup size was used is classic overkill.
Changing the gas cup size is a non-essential variable so the code committee has deemed that the chemical and metallugical properties of the weld will not be affected by a change in cup size.
However, then you have corrosion resistant alloys - this is where a change in gas cup size may affect the corrosion resistance of the completed weld.

In your industry it may be common to weld the same thing over and over in a controlled environment - then it is perfectly acceptable to nominate exactly what must be complied with.
But your industry is only a drop in the ocean and there are thousands and thousands of engineering companies world wide who couldn't possibly stay financially viable if they followed your recommendations.

The project I am currently on has 54 GTAW WPS's (C/S,S/S,DSS,SDSS, Monel & Inconel). These list under cup size #6, #7 or #8.
If I had to have a WPS for 3 different cup sizes I now need 162 WPS's.
15 of these are C/S so do I have a separate one for stringer bead and another for weave ?
That's now 177 WPS's.

Where do you stop ?

Regards,
DD