(2), overheating due to the sealing surface will produce heat, so the rubber ring temperature should be below the design specifications. Fluorine rubber and polytetrafluoroethylene use temperature of 216 ℃, NBR use temperature of 162 ℃, although they can withstand higher temperatures, but the heat generated by high sealing surface, so there continues vulcanized rubber ring The danger, ultimately loses its elasticity and leak. (Considering the cold crisp cold zone) between the sealing surface but also because of the heat caused by the crystallization medium, such as a knot of carbon, causing the sliding member is stuck and the sealing surface is condensed. And some of the polymer due to overheating and coking, lose some fluid lubrication due to overheating or even a flash fire. Superheated medium except for status change, it will aggravate the corrosion rate. Causing deformation of the metal parts of mechanical seals, cracking of the alloy surface, as well as certain coating cracks, the design should be used in balanced mechanical seal, to reduce the specific pressure to prevent overheating. (3), the ultra-poor correct assembly tolerances, for the installation of the mechanical seal is necessary, the shaft (sleeve) must have a suitable surface roughness and the correct size, but manufacturers rarely provide tolerance data, installation terms are very critical. (Rely on experience and common sense) mechanical seal dimensional accuracy and geometric tolerances must comply with the requirements of the drawings, the ultra-poor will lead to early failure of the seal. 2. Failure Analysis seal sealing surface itself would provide evidence of seal failure ISW40-200A mechanical seals, such as vibration, there will be signs of wear and tear on the transmission parts, such as traces of obvious, it is generally caused by improper assembly. Must be checked before the pump starts:. A sealing system for all fittings connected ISW40-200 whether mechanical seals, the system is in working condition. Inhalation valve should be open, until the liquid (medium) and then open the motor into the sealed chamber. b. the pump and seal chamber is filled with liquid. c. the sealed chamber Have exhausted air. Especially with the double-end sealing liquid seal, it should be noted drained air. d. Turning examination should feel resistance, but should not have a heavy or wiring. 13, double mechanical seal work ISW40-250 mechanical seal, isolation seal chamber pressure than the fluid medium pressure high 0.05-0.2MPa. 14, the relevant parameters: mechanical seal installation shaft (or sleeve) to be chamfered at the step 3 × 10 °, and the smooth transition, its roughness Ra≤1.6. Axis (or sleeve) surface roughness Ra≤1.6, runout ≤0.04mm, dimensional tolerances h6. Installation of mechanical seals and sealing cover secondary seal contact area of ??the surface roughness of the stationary ring Ra≤1.6, dimensional tolerances for H8, locating the vertical face of the shaft ≤0.04mm. ISW40-200A mechanical seals, mechanical seals, pipeline pumps supplied by Anguo Shi Yuan Pumps Limited. Anguo Shi Yuan Pump Co., Ltd. (www.shiyuanbeng.com) strong, credible, in Baoding centrifugal pumps and other industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead you hand pumps and stone yuan into the brilliant, for a better future!