A gap in one or both end faces, this phenomenon indicates the distance separating the two end too, and when the two end slam tight, it will have gaps. Common causes of end face separation is medium flash evaporation. For example, water, especially in the hot water system or a liquid containing condensate, the expansion of the water evaporates, and thus separated from the end faces. Pump cavitation plus blocking seal so that the seal face may be chipped reasons. In this case, not because of vibration and couplings are not in the Champions League this cause, because it is not enough to produce the end face gap. Lower end surface temperature to prevent rapid evaporation of the medium caused damage to the end face of the commonly used methods. At the same time, the use of materials with good thermal conductivity group is also advantageous, such as nickel-based alloy and copper leaching Graphite Group direct cooling of the right, in addition, the use of balanced mechanical seals, gland or the use of special note was cooled from the outside, or seal chamber, etc., to reduce the temperature of the seal faces is very effective.

Failure of mechanical seals, friction face often leave very fine radial cracks or blisters on both radial cracks mark, even cracking. This is due to the sealing due to overheating, especially ceramics, carbide seal surface prone to such damage. Medium, poor lubrication, overload, high operating temperatures, line speed, improper matching material combinations, any one factor, or superposition of several factors, can generate excessive frictional heat, if frictional heat can not be distributed, It will produce hot cracking, which appears excessive wear and high leakage. Seal overheating problem solving, in addition to changing the area of ??the outer end surface, reducing the load, but also the use of static seals and plus diversion forced cooling circulating fluid guide sleeve sealing surface, or in the sealed end face of the open hydrodynamic grooves to be addressed. Friction end face of many of the small hot spots and discoloration isolated area, indicating that the seal under high pressure and heat affected become distorted. For the thermal deformation of the end face of the general method of calculation is not allowed, shall be calculated using the finite element method in order to improve the design of the sealing ring.

Surface coating of a hard material seal ring, whether it is sprayed ceramic or carbide, the heat load in the surface layer are likely to continue their scaly or flaking on the substrate. This phenomenon, described seal appears too dry friction. In order to eliminate this phenomenon, we should first check the seal of lubrication, cooling is adequate, whether the clogging cooling system, operate it properly, take appropriate measures according to the actual situation.