A "simulator" test is for tube welders. The simulator simulates
conditions encountered while welding water walls for a boiler. It
consists of three pieces of tube with the test coupon in the
center. This is a restrictive test. Restrictive means it is tight
welding on each side. It is done in the 4G position, usually. A 6G
simulator test would be very, very hard to accomplish
successfully.
Glad I could help.
olhand