Issuing body
API
Latest edition
3rd Edition (2018)
Region
USA, Global
Equipment items
3
Scope
Type testing of valve stem packing material for fugitive emission performance (low-E packing).
Key requirements (7)
- Type testing of process valve packing for fugitive emissions.
- Test temperature: 260 °C (500 °F) typical.
- Test cycles: 1510 mechanical cycles + 5 thermal cycles.
- Leakage acceptance: ≤ 100 ppmv methane (or per spec).
- Materials qualified: graphite, PTFE, flexible-graphite die-formed.
- Mating shaft surface finish: typically Ra ≤ 0.4 µm (16 µin).
- Drives selection of low-emission packing for VOC service.