Pipe sewage pump mechanical seal before they go out to do the sealing performance test, and the certificate of approval. Mechanical seal after a long run, make ring and static ring wear, corrosion and wear spring on the shaft, o-ring seal wear, aging, deformation, etc., can lead to seal leak, to repair or replace a new one. Ring and static ring sealing surface can not have crack, fall off, scratches, pitting, flash and eccentric wear, scratch, pitting can't throughout the seal face. If use repair of dynamic and static ring, convex platform for static ring height not less than the sum of 3 mm, and a single convex platform height not less than LMM, lest affect heat dissipation. Ring after installation should guarantee can flexible movement, the shaft will ring should be free to bounce after pressure to the spring, vertical and parallel for static ring. Specifications conform to the requirement of drawings, for static ring gasket surface can not have the damage, and uneven thickness of the soft hard uneven phenomenon, to replace the o-ring seal during overhaul. The outer surface of the spring clean without rust, before use should be the length of the appearance test and stress test, each group of spring in the pressure difference between the compression length should comply with the prescribed requirements, compressed length of each group of spring under the error meets the requirements. Free length tolerance is not more than 0.5 mm, the compression quantity cannot be greater than small, error of plus or minus 2 mm. Gland and pump shaft can't use the same kind of material, on both sides of the end face of the parallelism tolerance and the perpendicular axis and tolerance is not more than + / - 0.20 mm. 

 

Second, the pipeline sewage pump to ensure adequate cooling and lubrication 

 

Adjust the cooling pipe valve opening, to ensure that the mechanical seal cooling pipe flow, open the drain valve when tank water pump to net gas inside the sealed cavity. 

 

Three, pipes, sewage pump to ensure the installation precision 

 

When disassembling the pump mechanical seal, dynamic and static ring to clean, and apply a small amount of cleaning on the surface of the friction pair of lubricating oil, to give attention to both high voltage and low voltage side, it is strictly prohibited to knock against. Static ring gland when installing the strength should be uniform, prevent partial pressure, with a feeler check, up and down or so position deviation is not more than 0.05 mm; Check the fit clearance of gland and shaft diameter, around wants even, the allowable deviation not more than 0.1 ram. Install the water pump mechanical seal parts of the pump shaft radial runout of not more than 0.05 mm. Before and pump cover and seal end cover, carefully check the mechanical seal installation location dimension, if positioning size does not conform to the requirements, can use GangDian adjustment between the shaft sleeve, but GangDian accuracy is higher, the thickness of not more than 0.01 mm. Measure the mechanical seal set of radial runout and seal face face runout meets the requirements. 

 

Mechanical seal, which had run for every gland loose moves in the sealing surface, the dynamic and static ring parts must be replaced, absolutely should not be to tighten the continue to use again. Because after such looseness, friction pair of the original trajectory change occurs, the sealing performance of the contact surface is easily damaged. 

 

Four, pipes, sewage pump end face specific pressure adjustment 

 

End face specific pressure is related to the sealing performance and service life of the important parameters, it and sealing structure, and the size of the spring and medium pressure. End face specific pressure overshoot and bad friction pair; Pressure is too small, easy to leak, often by manufacturer for a given range, face specific pressure usually take 3 ~ 6 kg/cm2. Size is adjusted pressure adjusting spring compression. Spring is expressed in A free length of spring stiffness of unit amount of compression under load for k, the required pressure with P, says these are the manufacturers of the given parameters. Compressed size in B, P/A - 13 = k, it is concluded that 13 = A - e/k, this is the size of the compressed spring installation. If the size of the spring after installation is too big, can increase the adjustment between the spring seat and spring cushion thickness, size is too small to reduce the thickness of the adjustment, adjust the thickness of the mat with micrometer measuring.