Issuing body
API
Latest edition
4th Edition (2014, R2020)
Region
USA, Global
Equipment items
1
Scope
Mechanical seal designs and seal piping/flushing plans (Plans 11, 13, 21, 23, 32, 52, 53A/B/C, 54, 62, 75, 76).
Key requirements (8)
- Mechanical seal categories: Cat 1 (general), Cat 2 (refinery medium), Cat 3 (refinery severe).
- Seal types: Type A (pusher), Type B (metal bellows), Type C (metal bellows hi-temp).
- Arrangements: 1 = single seal, 2 = dual unpressurized (tandem), 3 = dual pressurized (double).
- Standard piping plans: Plan 11 (flush from discharge), 13 (return to suction), 21 (cooler in flush), 23 (cooler in seal chamber pumping ring), 32 (external clean flush), 52 (unpressurized buffer), 53A/B/C (pressurized barrier), 54 (external pressurized barrier), 62 (quench).
- Plan 53B: pressurized bladder accumulator instead of nitrogen-pressurized pot.
- Plan 53C: piston accumulator referenced to discharge pressure.
- Seal chamber dimensions standardized for 25/40/50/80/100 mm shafts.
- Default qualification testing: 100-hour test on each seal series.
Related standards (2)
Applied to 1 equipment item
Rotating Equipment