1) Shaft diameter:
The shaft diameter range of the pump mechanical seal is generally 6-200mm, and the special one can reach 400mm. The shaft diameter of the pump is usually determined by the strength requirements and is rounded or modulated by a shaft sleeve to meet the standard shaft diameter of the mechanical seal;
2) Speed:
Generally, the speed is the same as that of the pump. The speed of the general centrifugal pump is less than or equal to 3000r/min; the speed of the high-speed centrifugal pump is less than or equal to 8000r/min, and the speed of the special pump is less than or equal to 4000r/min;
3) Average peripheral speed of the sealing surface:
Refers to the circumferential speed of the average diameter of the sealing end face. The average linear velocity of the sealing surface will generate more heat and wear on the sealing surface (ie friction pair). Generally, the peripheral speed of the unloading seal is less than or equal to 30m/s; the peripheral speed of the spring static mechanical seal is less than or equal to 100m/s; the special can be less than or equal to 150m/s;
4) End face-specific pressure:
The end surface-specific pressure Pc is the contact pressure (MPa) on the sealing surface. The end-face-specific pressure of the end-face seal should be controlled within a reasonable range, if it is too small, the sealing performance will be reduced, and if it is too large, the heating and wear of the sealing surface will be aggravated. Reasonable specific pressure value of the end face of the pump mechanical seal: built-in mechanical seal, generally take Pc=0.3-0.6MPa; externally installed mechanical seal, take Pc=0.15-0.4MPa. When the lubricity is good, the specific pressure of the end surface can be appropriately increased. For liquids with high viscosity, the specific pressure of the end surface should be increased. Pressure, preferably Pc=0.3-0.45MPa.
