Different type of SEAL FLUSH Plan

A mechanical seal of Cenrifugal pump requires flushing system to extend the life time. API 682 " Shaft sealing system for centrifugal and rotary pump" provide information of different type Flushing Plan system, as follow :

1. API Plan 01, recommended for clean fluids only.
2. API Plan 02, It is more common in the chemical industry in application with low seal chamber pressures and process temperatures. 
3. API Plan 11,The default seal flush plan for all single seals.
4. API Plan 13. The standard flush plan for vertical pumps that are not provided with a bleed bushing below the seal chamber.
5. API Plan 14. Combination of Plan 11 and Plan 13, it is most commonly used on vertical pump.
6. API Plan 21. Provides a cool flush to the seal.
7. API Plan 23. this plan of choice for all hot water services, particularly boiler feed water, and many hydrocarbon services.
8. API Plan 32. For application which a service containing solids or contaminants where a suitable cleaner or cooler external flush will improve the seal environment.
9. API Plan 41. Combination between Plan 21 and Plan 31 and specify for hot services containing solids.
10. API Plan 52. It is used in a service where no leakage to atmosphere can be tolerated.
11. API Plan 53a, 53b and 53c. Pressurized dual seal systems are used in services where no leakage to atmophere can be tolerated.
12. API Plan 54.Pressurized dual seal system with inner seal leakage into the pumped product.
13. API Plan 62. A quench stream is brought from an external source to the atmospheric side of the seal faces.
14. API Plan 71. Unpressurized dual seals, which utilize a dry containment seal and where no buffer gas is supplied but the provision to supply a buffer gas is desired.
15. API Plan 72. Unpressurized dual seals which also uses a dry containment seal.
16. API Plan 74. Dual pressurized seals, where the barrier medium is a gas.
17. API Plan 75. Unpressurized dual seals, which also utilize a dry containment seal and where the leakage from the inner seal may condense.
18. API Plan 76. Unpressurized dual seals which also utilize a dry containment seal and where leakage from the inner seal will not condense.

Continue with sketch drawings for each Flushing Plan type.