Seal Support System

API PLAN 53B

API Plan 53B is a modified version of API Plan 53A. API Plan 53B has only the piping and an air or water cooled heat exchanger within the closed loop circuit. The barrier pressure shall be generally 2Kg/Cm2 to 6Kg/Cm2 above box pressure. It consists of a bladder type accumulator, heat exchanger, either air cooled, finned tubing on water coolers, and instruments like pressure gauge, pressure switch / transmitters and temperature gauges / transmitters.

Objective

It is used in services where the process fluid leakage is eliminated.
Successfully used where the box pressure exceeds 10.0 Kg/Cm2 and temperature above 50 Deg C.
It is used where safety is of utmost importance and the media being sealed is extremely hazardous.
Preferably used where the margin between the box pressure and the vapour pressure at the pumping temperature is less.
Used in critical high pressure applications where use of plan 53A would allow nitrogen to become vapour and cause cavitation near the seal faces.
Used in applications where additional heat removal is required from the inner seal.

Advantages

Enhanced seal life at higher pressure and temperature as mixing of nitrogen with the barrier liquid is eliminated
There is no chance of the hazardous process liquid to leak provided barrier pressure is maintained.
Enhanced cooling of the inner and the outer seals
Make up of nitrogen pressure in the bladder accumulator using nitrogen charging kit is possible.
Monitoring of both inner seal leakage and outer seal leakage is possible.

Technical Features

Bladder accumulator in either carbon steel or SS316L and bladder material in nitrile for temperature up 120 Deg C & Viton for higher temperature
Capacity of bladder accumulator : 20 Liters 35 Liters 50 Liters Others as per requirement.
Heat Exchangers - Air Cooled either natural or forced circulation type - Finned tubes Heat Exchanger- Water cooled
A decrease in pressure indicates either inner seal or outer seal has leaked
Circulation is provided with the help of internal circulating devices line pumping ring, pumping screw.
Designed in accordance with ASME Section VIII Division 1 and API Standard
Bladder is pre-charged with 90% of working pressure
Based on API 682 4TH edition, pressure alarm is being set considering maximum and minimum temperature of site location.
Transmitters are either HART or foundation fieldbus (FF) protocol