scope:

1 Scope

1.1 This standard covers the requirements for testing and evaluating the performance of valve stem packing when it is exposed to a fire as defined in this standard. Packing may be a combination or an arrangement of more than one material. The test procedure in this standard simulates circumstances that impose severe demands on valve stem packing.

1.2 The requirements described in this standard establish performance limits for evaluating valve stem packing acceptability.

Note: The maximum acceptable leakage rates given in this standard are for the test temperatures and pressures specified. Leakage rates of valves in service during and after an actual fire may be substantially different.