FCI 70-2 :

The standard was revised in 2003 to add the option to permit low pressure gas testing to
determine Class V leakage. During the canvass of the 2003 version, one respondent asked for
the standard to be modified to specifically exclude on/off valves used for tight shut-off. The FCI
Control Valve and Regulator Section notes that FCI 70-2 has been intended to apply to control
valve seat leakage. If line isolation and/or absolute tight shut-off is a normal expectation of the
valve application, the FCI Control Valve and Regulator Sections recommend specifying another
standard, such as API 598, “Valve Test and Inspection.”

So, FCI seems not to be the correct reference standard for on/off valves.