i agree that variable 21 is basically a branch to variable 19, that's how i see it, however i don't know why the information is given that particular way. these particular variables ( 19 and 21) only pertain to a PQR as i see it. and variable 20 pertains to both PQR's and prequalified WPS's per 3.6, if i am correct than why wouldn't a prequalified WPS need to be revised or a new one produced if a change in shielding gas mix percentage has taken place? i'm tryin to stay caught up, but i'm learnin, learnin, learnin.
thanks,
JJ