API St 622:2011 specifies the requirements for comparative testing of valve stem packing for process applications where fugitive emissions are a consideration. Packing(s) shall be suitable for use at service temperatures –29 °C to 538 °C (–20 °F to 1000 °F). Factors affecting fugitive emissions performance that are considered by this standard include temperature, pressure, thermal cycling, mechanical cycling, and corrosion.
This standard is not intended to replace type testing of valve assemblies or valve production testing.
This standard establishes requirements and parameters for the following tests:
a) fugitive emissions,
b) corrosion, and
c) packing material composition and properties.
Test methods apply to packing for use in on-off valves with the following stem motion(s):
a) rising stem, and
b) rotating stem.
The test for fugitive emissions is based upon elements of EPA Method 21, providing comparative values of packing performance.
