Application of pump mechanical seal under high temperature medium:
Now, pump mechanical seals are developing towards high parameters (high temperature, high pressure, high speed and large shaft diameter). The high temperature direction is one of them. The viscosity and lubricity of most liquid media will decrease at high temperature, and the corrosiveness will increase. At the same time, the conventional auxiliary seal ring, end face seal pair and spring materials used will become unstable when the temperature is higher than 250°C. For example, rubber parts will lose elasticity, PTFE seals (the use temperature cannot be higher than 220 ℃) lose their original dimensional accuracy, the end face of the hard seal will be thermally deformed or cracked, and the end face of the carbon graphite soft ring will be blistered. The temperature of the sliding end surface will cause coking and solidification, which will seriously affect the normal operation of the seal.
According to the choice of pump mechanical seal material, under high temperature conditions, hot-pressed sintered SiC for antimony graphite or solid cemented carbide for copper graphite is recommended for the sealing pair; high nickel alloy is recommended for spring material; auxiliary seal ring material is recommended Inorganic materials.
For the sealing of high temperature and flammable media, it is recommended to use a tandem pump mechanical seal with an unpressurized quench fluid. On the atmosphere side, the quenching fluid can prevent the deposition of cracked products, and it can also prevent the direct leakage of the warm medium.