scope:

This API Standard specifies the requirements for comparative testing of block valve stem packing for process applications where fugitive emissions are a consideration. Packing(s) shall be suitable for use at -20°F to 1000°F (-29°C to 538°C). Factors affecting fugitive emissions performance that are considered by this Standard include temperature, pressure, thermal cycling, mechanical cycling and corrosion.

This standard does not provide acceptance criteria for valve packing, nor is it intended to replace proof testing of valve assemblies or valve production testing.

This standard establishes requirements and parameters for the following packing tests.

a. Fugitive emissions

b. Corrosion

c. Packing material

Test methods apply to valve packing for use with the following stem motion(s):

a. Rising stem (eg: gate valves)

b. Rotating stem (eg: ball valves)

The test for fugitive emissions is based upon elements of EPA Method 21, providing comparative values of packing performance.

Suitability of packing tested to this standard for use in a manufacturer's valve may be confirmed by re-testing the packing in the actual valve in accordance with Section 4 of this Standard. Acceptance criteria shall be by mutual agreement between the valve manufacturer and purchaser.