Chemical pump seal form

1. Oil seal seal
It is a self-tightening lip seal with simple structure, small size, low cost, convenient maintenance, and small resistance torque. It can prevent medium leakage and external dust and other harmful substances. It has a certain compensation ability, but it is not resistant to high pressure, so it is generally used in chemical pumps in low pressure situations.
2. Gasket seal
Gaskets are the basic components of centrifugal pump static seals and are used in a wide range of applications. The selection of the gasket is mainly determined by factors such as the medium, temperature, pressure and corrosion of the chemical pump.
3. Thread sealing
There are generally two forms on chemical pumps, one is threaded connection gasket seal, the other is threaded plus filler seal, both of which are used for sealing occasions with small diameter threaded connections. The seal of the threaded electric diaphragm pump connected to the gasket seal is a gasket, and the thread only plays the role of providing compression force.
4. Labyrinth seal
When the design is reasonable, the processing is excellent, the assembly is complete, and the speed is high, the labyrinth sealing effect is very good. However, in practical applications, the resulting chemical pump leaks a lot, so it is not commonly used in chemical pump seals.
5. Packing seal
It is to put the packing rich in compressibility and resilience into the stuffing box, and rely on the axial pressing force of the gland to convert into radial sealing force, so as to play a sealing role.
This sealing method is called packing seal, and this kind of packing is called sealing packing. Due to the simple structure of the packing seal, convenient replacement, low price, wide range of speed, pressure and medium, it is widely used in the design of chemical pumps.
6. Power seal
When the chemical pump is in operation, the pressure head generated by the auxiliary impeller balances the high-pressure liquid at the outlet of the main impeller, thereby achieving sealing. When the pump is stopped, the auxiliary impeller does not work, so it must be equipped with a parking sealing device at the same time to solve the chemical pump leakage that may occur when the pump is stopped.
The sealing structure of auxiliary impeller is simple, reliable and has a long service life. It can realize watertightness during the operation of chemical pumps, so it is often used in chemical pumps that transport impurities-containing media.
7. Mechanical seal
The most widely used sealing form in the chemical pump industry, because the mechanical seal has the advantages of less leakage and long life, so the mechanical seal is the most important shaft sealing method in these equipments in the world today. The mechanical seal is also called the end face seal, which is defined in the relevant national standards as follows: "At least one pair of end faces perpendicular to the axis of rotation are kept in contact with each other under the action of the fluid pressure, the elastic force (or magnetic force) of the compensation mechanism, and the cooperation of the auxiliary seal. A device that prevents fluid leakage by sliding relative to each other."