Common forms of sealing for thermal oil pumps
1. Skeleton seal: It is a self tightening lip seal with a simple structure, small size, low cost, easy maintenance, and low resistance torque. It can prevent medium leakage, as well as external dust and other harmful substances from entering. It also has the ability to compensate for wear, but is not resistant to high pressure. Therefore, it is generally used in low-pressure thermal oil pumps, such as KCB series thermal oil pumps and 2CY series thermal oil pumps.
2. Gasket sealing: Gaskets are the basic components of centrifugal pump static sealing and have a wide range of applications. The selection of gaskets is mainly determined by factors such as the conveying medium, temperature, pressure, and corrosiveness of chemical pumps. Mainly used for sealing the pump body of Y-shaped centrifugal pumps, the material is mostly aluminum sheet.
3. Threaded seal: There are generally two forms of sealing on chemical pumps, one is the threaded gasket seal, and the other is the threaded filling seal, both of which are used for sealing small diameter threaded connections. The sealing element for the gasket seal of the threaded electric diaphragm pump is the gasket, while the thread only serves to provide clamping force. This seal is rarely used in the gear pump series and can be used for on-site emergency purposes.
4. Maze seal: When the design is reasonable, the processing is excellent, the assembly is complete, and the speed is high, the labyrinth seal effect is very good. However, in practical applications, there are many chemical pump leaks caused by this, so it is not commonly used in chemical pump sealing.
5. Packing sealing: It is the process of placing compressed and resilient packing into a packing box, and converting the axial compression force of the gland into radial sealing force to achieve a sealing effect. This sealing method is called packing sealing, and this packing is called sealing packing. Due to its simple structure, easy replacement, low cost, adaptability to speed, pressure, and wide range of media, packing sealing is widely used in the design of gear pumps. For example, YCB series products and so on
6. Power seal: When the chemical pump is in operation, the pressure head generated by the secondary impeller balances the high-pressure liquid at the outlet of the main impeller, thereby achieving sealing. When parking, the auxiliary impeller does not work, so a parking sealing device is also equipped to solve the possible chemical pump leakage during parking. The sealing structure of the secondary impeller is simple, reliable, and has a long service life. It can achieve zero leakage during the operation of chemical pumps, so it is often used in pumps that transport media containing impurities.
7. Mechanical seal: Nowadays, it is widely used as a sealing form in the chemical pump industry. Due to its advantages of low leakage and long service life, mechanical seal is the main shaft sealing method in these equipment in the world today. Mechanical seal, also known as end face seal, is defined in relevant standards as follows: "A device that prevents fluid leakage by keeping at least one pair of end faces perpendicular to the axis of rotation in contact and sliding relative to each other under the action of fluid pressure and compensation mechanism elasticity (or magnetic force), as well as auxiliary sealing. This seal can be used universally in gear pump series with skeleton seal and packing seal, and has significant characteristics such as no leakage and long service life.
