API Plan 53B

• The barrier fluid and nitrogen are separated by a bladder which effectively prevents the nitrogen from mixing with the barrier fluid as in the case of a Plan 53A.
• The pumped medium generally does not leak to the atmosphere unless the bladder pressure is lost.
• High reliability as a stand-alone system without need for a permanent nitrogen source and external pressure.
• Heat removal by water or air cooler.
• Uses an internal circulating device to ensure barrier liquid circulation.
• Barrier liquid enters the process medium through the inner seal faces.

• 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 at required pressure.
• For applications with barrier pressures above 16 bar (232 PSI) where Plan 53A cannot be used.

• Check with the process engineer if product contamination is acceptable.
• Check barrier fluid compatibility with the media.
• Always pre-charge the bladder at the correct pressure to ensure the required barrier pressure at the operating temperature. Refer to the nameplate affixed to the accumulator.
• 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).
• Since there is less barrier fluid volume in the accumulator, heat dissipation is a function of the cooler efficiency.

• Suspended solids
• Polymerizing and contaminated media
• Poor lubrication properties
• Hazardous / environmentally harmful
• Leakage may form solids
• 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