JB/T 6619.1-2018Light mechanical seals - Part 1: Specification (English PDF)

4.1 Sealing ring

4.1.1

The flatness requirements of the sealing end face of the sealing ring: the flatness error of the hard sealing ring of the light mechanical seal shall not be greater than 0.0006 mm, and the flatness error of the soft sealing ring shall not be greater than 0.0009 mm.

4.1.2

Requirements for the surface roughness of the sealing end face of the sealing ring: the surface roughness Ra of the hard sealing ring for the mechanical seal of the automotive engine cooling water pump shall not be greater than 0.2 µm; the surface roughness Ra of the soft sealing ring shall not be greater than 0.4 µm. The surface roughness Ra of sealing ring of cemented carbide for light mechanical seal shall not be greater than 0.1 µm, and the surface roughness Ra of the soft sealing ring shall not be greater than 0.2 µm.

4.1.3

The sealing end face of the sealing ring shall be free from scratches, pores, cracks and other defects on the substrate.

4.1.4

The parallelism of the sealing ring with the sealing end face and the positioning end face in contact with the auxiliary seal shall meet the requirements of grade of tolerance 7 specified in GB/T 1184-1996.

4.1.5

The verticality of the sealing end of the stationary or rotating ring to the outer circle or inner bore in contact with the auxiliary seal of the ring shall meet the requirements of grade of tolerance 7 specified in GB/T 1184-1996.

4.1.6

The surface roughness Ra of the part where the sealing ring is in contact with the auxiliary seal shall not be greater than 1.6 µm.

4.1.7

Cemented carbide sealing ring, silicon carbide sealing ring, carbon graphite sealing ring and alumina ceramic sealing ring shall meet the requirements of JB/T 11959, JB/T 6374, JB/T 8872 and JB/T 10874 respectively.

4.1.8

The compensation ring assembly shall be able to move freely along the axial direction without blocking.

4.2 Springs

The size, precision and working load of springs shall meet the requirements of JB/T 11107. Rust spots are not allowed on the surface of the spring. For coated springs, the coating must not come off.

4.3 Rubber bellows

The design of rubber bellows shall ensure the reliability of sealing and torque transmission. The surface of rubber bellows and other rubber auxiliary seals shall be smooth and flat without any bubbles, slag inclusions or unevenness, and there shall be no flash in the sealing part. The physical and chemical properties of the rubber compound and appearance specifications of rubber components shall meet the requirements of JB/T 7757.2.

4.4 Rubber O-rings

The technical requirements of rubber O-rings shall comply with the provisions of JB/T 7757.2.

4.5 Stampings

Stampings shall not have burrs, wrinkles, rust spots, etc., and there must be no longitudinal stripes in the sealed part. Coated stampings are not allowed to peel off the coating.

5.1 Leakage

There shall be no visible air bubbles in the air tightness test.

Leakage of static pressure test and running test: the leakage rate of mechanical seal for electric submersible pumps shall not exceed 0.1 mL/h, the leakage of mechanical seal for automotive engine cooling water pump shall comply with the provisions of JB/T 11242, and the leakage of mechanical seal for other pumps shall not exceed 2 mL/h.

5.2 Abrasion loss

The abrasion loss shall meet the requirements of its service life, and the test shall be carried out in clean water. After running for 100 hours, the abrasion loss of the sealing ring of the soft material shall not be greater than 0.02 mm.

5.3 Service life

In the case of reasonable selection and correct installation and use, the service life of the light mechanical seal shall not be less than 8,000 h. When used in special conditions, the service life is determined by the buyer and the seller through negotiation.