A welder shall be requalified whenever a change is made
in one or more of the essential variables listed for each
welding process.
Where a combination of welding processes is required
to make a weldment, each welder shall be qualified for the
particular welding process or processes he will be required
to use in production welding. A welder may be qualified
by making tests with each individual welding process, or
with a combination of welding processes in a single test
coupon.