Seal Selection, What Is The Common Sense Of Mechanical Seals?

The selection of seals must consider the working conditions, so as to choose the appropriate form of seals and materials, installation structure. The working conditions to be considered generally include temperature, pressure and medium. Others also need to be combined with the characteristics of the equipment itself to consider the selection. About the temperature, such as the working temperature of NBR material, the mechanical seal circumference is generally -40 ~ +120℃. That is beyond 120℃ to consider the use of FKM, or even PTFE material. Low temperature is relatively rare, generally speaking, in the case of -20 ~ -40℃ to consider the use of cold-resistant NBR, general NBR materials in low temperature environment will lead to material hardening, resulting in leakage, such as railway locomotives in the northern winter often appear such problems. As for pressure, it affects the form of seals to be used.

Generally speaking, low and medium pressure rubber or PU seal will not be too big a problem. But to consider the problem of impact pressure, such as construction machinery in the start, close when its impact pressure is much greater than the normal working pressure, so will often choose the pressure up to 70MPA impact anti-squeeze HBY mechanical seal or SPGW as the main seal. PTFE combination seals are also a common option. The medium problem is simpler. There are only a few special issues that need to be noted, such as water-glycol and phosphate ester hydraulic fluids used in cylinders in the metallurgical industry. Sometimes although the working temperature is not high, but the choice of material or very careful, hydraulic oil when using the latter or choose FKM. The selection of seals is very important, or must be combined with the situation of the equipment itself. For example, if you want responsive, precise control, of course you want steffengelet. In order to have high reliability, HONgel's GD1000K series or NOK's SPGW are often selected. For example, when the field work of engineering machinery often has impact and low temperature weather, its dust ring will choose exposed metal skeleton to avoid falling off. Cylinders, compressor rings, high-pressure oil seals, and oil pumps in various scientific instruments all require special seals to meet the requirements.

Mechanical seals belong to one of the precise and complex mechanical basic components, and are the key components of various pumps, reaction synthesis kettle, turbine compressor, submersible motor and other equipment. Its sealing performance and service life depend on many factors, such as type selection, machine accuracy, correct installation and use, etc.