Description: Plan 52 is an
external reservoir, typically
NON‐PRESSURIZED or
maintained at a pressure less
than the pressure in the seal
chamber. Provides BUFFER
fluid for the outer seal of an
Arrangement 2 dual seal.
Circulation provided by an
internal pumping ring.
Objective: To reduce human
and environmental contact
in the event of a primary
seal failure. Lubricate outer seal.
Advantages: No process
contamination. Enhanced cooling
available using cooling coils in the
reservoir. Best for hazardous
fluids, light hydrocarbons and
vapors which are contained by a
safety backup seal.