IPSO DR30SLG Owner's Manual page 19

Gas Piping Installation (Illustration)
The dryer and it's individual shutoff valve must be disconnected from the gas supply piping system
during any pressure testing of that system at test pressures in excess of 1/2 psi (3.5 kPa).
The dryer must be isolated from the gas supply piping system by closing it's individual manual shutoff
valve during any pressure testing of the gas supply piping system at test pressures equal to or less
than 1/2 psi (3.5 kPa).
Page 19