Plan 53B

In Piping Plan 53B, there is an external barrier fluid system pressurized by a bladder accumulator supplying clean liquid to the barrier fluid seal chamber. The accumulator and barrier liquid are maintained at a pressure greater than seal chamber pressure. [API 682; G.19]. The pressure is maintained in the system by a bladder-type accumulator. The bladder prevents contact between the pressurized gas and the barrier fluid.

Standard Features

  • Bladder accumulator, non-code, CS construction
  • Shell and tube heat exchanger, non-code, CS shell, copper tubes
  • Pressure indicator
  • Pressure switch with instrument valve
  • CS valves
  • 316SS tubing and fittings


  • API 682 compliant
  • ASME U stamp, ASME VIII, Div. 1 2015 for vessels
  • SS valves and vessel
  • All instrument types, ranges, and certifications
  • Custom design