Rotary Seal
Advantages: simple structure, low cost, easy to install, suitable for multi-stage series pumps.
Disadvantages: high power consumption, severe shaft wear, easy to heat and smoke, not suitable for high temperature, flammable, explosive and corrosive media.
Mechanical seal (end face seal)
Advantages: less leakage, long life (up to 25,000 hours), suitable for high pressure, high temperature and media containing solid particles.
Disadvantages: complex structure, high cost, difficult maintenance.
The shaft seal is a friction seal or stuffing box, which is used to prevent liquid leakage between the shaft and bearing of the compressor or other fluid conveying equipment. It is also a sealing device set to prevent leakage between the pump shaft and the housing. Common shaft seal types include packing seals, mechanical seals and power seals.
The shaft seal of a reciprocating pump is usually a packing seal. When the medium that does not allow leakage is transported, a diaphragm reciprocating pump can be used. The shaft seals of rotary pumps (including vane pumps, rotor pumps, etc.) mainly include packing seals, mechanical seals and power seals.
Packing seals Packing seals have a simple structure, low price and easy maintenance. However, the leakage is large and the power loss is large. Therefore, packing seals are used to transport general media, such as water; they are generally not suitable for petroleum and chemical media, especially for precious, explosive and toxic media. Mechanical seals Mechanical seals (also called end face seals) have good sealing effect, small leakage and long life, but they are expensive, and the processing, installation, maintenance and maintenance requirements are higher than those of general seals. Mechanical seals are suitable for transporting petroleum and chemical media, and can be used for various media with different viscosities, strong corrosiveness and particles. The American Petroleum Institute standard API610 (8th edition) stipulates that unless otherwise specified by the user, a cartridge mechanical seal should be installed.
