What are the effects of temperature on the use of mechanical seals for slurry pumps

There are many reasons for the failure of mechanical seals for slurry pumps, such as seal end face wear, corrosion, high temperature, errors in installation, operation or the equipment itself, which lead to seal failure. Among them, the reasons for the failure of seals due to high temperature are more critical. In this regard, we will introduce and understand them in detail.

(1) Thermal cracking is a common failure phenomenon of mechanical seals for slurry pumps, such as residual oil pumps, oil return pumps, atmospheric and vacuum tower bottom pumps, etc. Due to dry friction at the sealing surface, sudden interruption of cooling water, impurities entering the sealing surface, evacuation, etc., radial cracks will appear on the annular surface;

(2) Graphite carbonization is one of the main reasons for the failure of the seal when using carbon-graphite rings. Since in use, if the graphite ring exceeds the allowable temperature (generally -105 ~ 250 ℃), resin will precipitate on its surface, The resin near the friction surface will be carbonized. When there is a binder, it will foam and soften, which will increase the leakage of the sealing surface and cause the sealing to fail;

(3) Auxiliary seals (such as fluorine rubber, ethylene-propylene rubber, all rubber) will rapidly age, crack, harden and lose elasticity after exceeding the allowable temperature. The flexible graphite currently used is resistant to high temperature and corrosion. Good, but its resilience is poor. And it is brittle and easy to be damaged during installation.

The poor welding quality of the piping system of the sealing device seriously affects the safety of the feed pump. The temperature of the sealing fluid of the feed pump is designed to alarm at 80°C, and the pump jumps at 90°C. The leakage of the piping system of the sealing device will cause the temperature of the sealing liquid to rise sharply, and the sealing dynamic ring, the static ring and the contact surface cannot be well cooled, which will cause the dynamic and static rings to overheat and be damaged.

To sum up, according to the influence of temperature on the use of mechanical seals for slurry pumps, its use failures can be greatly reduced, thereby effectively prolonging its service life.