1. The plane of the sealing end surface shall not be greater than 0.0009mm (i. e., three monochromatic optical interference zones); the Ra of the end surface of hard material is not greater than 0.2 μ m; the Ra of soft material is not greater than 0.4 μ m; the surface shall not be free of cracks, scratches, pores and loose defects
2. The parallelism of the sealing end surface of the sealing ring and the auxiliary sealing ring is specified according to the level 7 accuracy of GB1184-80.
3. The verticality of the sealing ring end surface and the inner (or outer) circular surface of the mounting auxiliary sealing ring shall be specified according to the level 7 accuracy of GB1184-80.
4. The surface roughness Ra value of the contact site with the auxiliary sealing ring is not greater than 3.2 μ m; the size tolerance of the outer circle or inner hole is hg or Hg.

The above requirements are for the ordinary pump mechanical sealing ring, for the lower speed kettle mechanical sealing can be appropriately relaxed or refer to the corresponding standard, and the high-speed mechanical sealing is higher.