Answer 1

As per API Std-598 the new valves maximum allowable leakage rates are as follows:

Valve   Type	Maximum Leakage Allowed, gpm (m3/sec)
Gate	0.0003 (1.9 X 10-8)
Globe	0.0003 (1.9 X 10-8)
Plug	0.0003 (1.9 X 10-8)
Metal Seated Check	0.0006 (3.8 X 10-8)