Pressurized barrier fluid circulation with bladder accumulator .
Fluid is circulated by a pumping ring in the dual seal
Isolate process fluid .
Zero process emissions .
Higher pressure than Plan 53A .
Used with dual pressurized seals .
High vapor pressure fluids ,light hydrocarbons .
Hazardous /toxicfluids .
Heat transfer fluids
Dirty /abrasiveor polymerizing fluids .
Piping loop must be fully vented before starting
Accumulator must be pressurized at all times ,usually by gas
charge .Barrier fluid must be compatible with process .
Regularly monitor barrier pressure manually add barrier
fluid when pressure decays