The mechanical seal is a mechanical part with higher precision, and its correct installation and operation have a great influence on its service life. We generally follow the standards set by the Ministry of Petroleum and Chemical Industry.
The technical requirements for the matching part of the pump with the mechanical seal and the mechanical seal are as follows:
1. Shaft curvature: no more than 0.05 mm;
2. Rotor vibration: the vicinity of the shaft sleeve at the sealing ring of the moving ring is not more than 0.06 mm;
3. The axial movement of the shaft is not allowed to exceed ±0.5 mm. If there is a shaft sleeve, no looseness of the shaft sleeve is allowed;
4. Coupling alignment error: for gear couplings, it is not more than 0.08～0.10 mm (P2008C), for elastic couplings, it is not more than 0.05～0.06 mm; (customary practice end jump <0.05, radial jump <0.10 )
5. The concentricity tolerance of the gland (stationary ring seat) and the seal fitting stopper to the shaft centerline is 0.05mm, and the perpendicularity value of the plane contacting the gasket to the centerline is 0.03～0.05mm, if it cannot be reached Requirements, the sealed cavity must be processed;
6. The end of the sleeve where the moving ring sealing ring is installed, and the end of the gland (or housing) where the static ring sealing ring is installed should be chamfered and smoothed.
(1) Be careful when installing and disassembling the mechanical seal. Hand hammers and flat shovel are strictly forbidden to avoid damage to the sealing elements. If the fouling cannot be removed, it should be cleaned and then removed.
(2) If mechanical seals are used at both ends of the pump, take care of each other during assembly and disassembly to prevent one from losing one another.
(3) For the mechanical seal that has been in operation, if the gland is loose and the seal moves, the dynamic and static ring parts must be replaced, and should not be re-tightened for continued use. Because the original running trajectory of the friction pair will change after loosening, the sealing of the contact surface is easily damaged.
