water pump machine seal against dynamic and static ring fitting anti-leakage by dynamic ring stationary seal ring and other common leakage failure source

Definition and Principle

Pump seal, also known as mechanical seal, is a precision component used in pump products. It relies on a pair of end faces (the moving ring and the static ring) perpendicular to the rotating axis to adhere and slide relative to each other under the action of fluid pressure and compensating mechanical external force, preventing fluid leakage.

Structure and Material

It is mainly composed of dynamic rings, static rings, springs, seals, etc. The material selection is diverse, such as graphite with good self-lubrication and small expansion coefficient; silicon carbide alloy ceramic is wear-resistant and corrosion-resistant, often selected according to the working condition for soft - hard combinations, and when there are particle media, hard - hard combinations are selected.

Common Problems and Their Causes

- Leakage: Installation static leakage may be due to seal ring or friction pair problems; trial operation leakage is often caused by the destruction of the dynamic and static ring friction pairs, such as abnormal operation, improper installation compression, medium with particles, or incorrect selection.

- Failure: including the absence of lubrication film leading to dry friction, media flash evaporation, corrosion (pitting, intergranular corrosion, etc.), high-temperature effects (thermal cracking, graphitization, etc.), seal face wear (poor wear resistance of the material, the entry of particles, etc.).

Maintenance Points

Guarantee the quality of parts, conduct sealing performance tests before installation; Ensure sufficient cooling and lubrication, and the smoothness of the piping; Ensure installation accuracy, avoid knock-offs and pressure deviations; Reasonably adjust the face pressure ratio. Hardware tools.