API Plan 53 mechanical seal auxiliary system

PI Plan 53 mechanical seal auxiliary system is designed for dual - pressurized mechanical seals, which provides clean, cooled barrier fluid at a pressure higher than that of the pump seal chamber to ensure zero - emission of process fluids. It mainly includes the following three subtypes:

- API Plan 53A: It uses an external gas - pressurized isolation reservoir to supply clean isolation fluid to the seal chamber. The reservoir is pressurized by inert gas (usually nitrogen), and the pressure of the isolation fluid is controlled by an external gas regulator. The pressure of the external seal chamber should be 0.14 - 0.17 MPa higher than that of the sealed medium. It has a simple external pipeline system and is widely used, but the pressurized gas directly acts on the isolation fluid, which may cause gas to dissolve into the liquid and affect the operation of the seal.

- API Plan 53B: It pressurizes the seal fluid circulation system through a bladder - type pressure - increasing device, and then circulates it through a pump. At the same time, heat is removed by air - cooling or water - cooling. The pressure of the bladder - type pressure - increasing device is provided by an internally - inflated bladder. It solves the problem of gas - isolation fluid dissolution in Plan 53A, and can compensate to a certain extent when the isolation fluid leaks.

- API Plan 53C: The isolation fluid is indirectly pressurized by the medium through a pressure - increasing tank, which is used in the working conditions where the medium pressure fluctuates greatly. The pressure - increasing tank is a piston - type accumulator. The integrated - design flushing system uses the pumping ring at the seal to provide power to automatically pressurize the isolation fluid. The split - design flushing system cools the isolation fluid in a cooler and then circulates it into the seal chamber for cooling and flushing, and realizes automatic pressurization of the isolation fluid through a branch pipe connected to the upper part of the pressure piston.