API Plan 53C

• A piston accumulator dynamically adjusts the barrier pressure which is based on the seal chamber pressure, thus maintaining a fixed, steady differential pressure across the inboard seal faces.
• Barrier liquid enters the process medium through the inner seal faces.
• Uses the seal chamber pressure as a reference pressure and accordingly magnifies the barrier pressure by a pre-defined ratio.
• Highly reliable since there is no need for an external pressure source.
• Heat is removed with the help of a water cooler or an air cooler.
• Uses an internal circulating device to ensure barrier liquid circulation.

• For services where product dilution is acceptable.
• For services where media is unsuitable for flushing the inner seal faces.
• For services where Plan 53A cannot be used due to non-availability of a permanent, reliable nitrogen supply.
• Ideal plan for applications with varying seal chamber pressures. Pressure ratio depending on stuffing box pressure range:
  • 4 bar (58 PSI) ... <10 bar (145 PSI) = piston ratio 1:1.5
  • 10 bar (145 PSI) ... <22 bar (319 PSI) = piston ratio 1:1.2
  • 22 bar (319 PSI) ... 40 bar (580 PSI) = piston ratio 1:1.1;
    For stuffing box pressures less than 4 bar (58 PSI) or above 40 bar (580 PSI) consult EagleBurgmann.
• Check with the process engineer if product contamination is acceptable.

• Check barrier fluid compatibility with the media.
• Vent the system before start-up. Later ensure that the vent line always remains closed.
• Sense the seal inlet and outlet line temperatures. Difference in the temperatures is an indication of proper flow.
• Ensure that the barrier pressure is always higher than the seal chamber pressure by at least 1.4 bar (20 PSI) (for piston ratio selection).
• Since there is less barrier fluid volume in the accumulator, heat dissipation is very much a function of the cooler efficiency.
• Ensure that the seal chamber reference line is not choked and that it is connected to the downstream of the accumulator.
• Ensure proper heating or cooling of the reference pressure line if necessary.
• Check the compatibility of the accumulator materials with the pump media.

• Non-polymerizing and clean media
• Poor lubrication properties
• Hazardous / environmentally harmful
• Close to vaporization point
• Can tolerate dilution with barrier media

• Between seals
• Barrier system (p_sealchamber < p_betweenseals)
• Lubrication, flushing and cooling for both inboard as well as outboard seals

3CW-FB, 3CW-BB, 3CW-FF