API PLAN 75
A containment seal chamber leakage collection system for condensing or mixed phase leakage on arrangement 2 unpressurized seals with containment seals.
- This plan can be used with buffer gas (Plan 72) or without buffer gas (Plan 71).
- Avoids direct leakage of pumped media to the atmosphere.
- Liquid leakage is collected in the leakage collector and vapors pass to the collection system.
- Excessive leakage and the use of an orifice in the outlet line of the collector together leads to a pressure build-up in the collector and triggers a pressure alarm at 0.7 bar (10 PSI) with the help of a pressure transmitter.
Remarks, Checkpoints :
- Set the pressure transmitter alarm to a pressure of 0.7 bar (10 PSI) so as to trigger an alarm when the pressure in the leakage collector increases. This indicates inboard seal leakage.
- Ensure that the vent line is always open and an orifice is present to generate back pressure.
- Always mount the leakage collection system below the pump centerline.
- Use sloping lines from the CSD port to the leakage collector.
- Use the level gauge to ascertain if the leakage collector needs to be drained.
Recommended Application :
- For condensing media.
- For configurations utilizing an outboard containment seal – contacting or non-contacting type.
- Generally used in combination with a Plan 72 nitrogen purge.