Pressurized barrier fluid circulation with piston accumulator .
Fluid is circulated by a pumping ring in the dual seal
Isolate process fluid .
Zero process emissions .
Higher pressure than Plan 53A .
Dynamic tracking of system pressure ...
Used with dual pressurized seals .
High vapor pressure fluids ,light hydrocarbons .
Heat transfer fluids
Piping loop must be fully vented before starting
Reference line must tolerate process contamination without
plugging .Barrier fluid must be compatible with process .
Reservoir level indicator indicates both inboard and outboard
seal leakage .