If you are qualifying a welder on 1" pipe and thickness of the pipe is less than 13mm, then the welder is qualified a maximum of 2t, where t is the thickness of the pipe. no minimum thickness...
The welder MAYA be qualified for more than 1 WPS. It just depends upon the range the welder is qualified AND the range that the WPS is used for production.
A welder may be qualifiied to work within the range of a WPS but may not be able to work within the entire range. The term "Qualified for a WPS" can be misleading. A welder may be qualified for ranges that a WPS's does not yet exist for in the company. Or he may use a WPS but not be qualified for the entire range.
If trhat was not what you were referring to, forgive me.
Gerald Austin
Iuka, Ms