But the idling vertical acid-alkali-resisting pump a wide variety of different models, but the leak, there are five main office:
( L ) between the sleeve and the shaft seal;
( 2) the moving ring and the shaft sleeve seal;
( 3) dynamic, static inter-ring seal;
( 4) of the static ring and the static ring seat seal;
( 5) the sealing end cover and the seal between the pump body.

In general, sleeve projecting shaft, sealing end cover and a pump body leakage is relatively easy to detect and resolve, but be careful observation, especially when the working medium for the liquefied gas or high pressure, toxic and harmful gas, relatively more difficult. The rest of the leak is an intuitive and judgment, should be in the long-term management of repair, on the basis of practice, the leakage symptoms were observed, analysis, judgment, we can draw a correct conclusion.

One, leakage reason analysis and judgement
1 installation of static test of leakage. Good mechanical seal installation, generally try to be quiet, observation of leakage. Such as leakage of smaller, more dynamic or static ring ring ring problems; leakage is large, then the dynamic, static ring friction pairs of problems. The preliminary observation of leakage, judgement leakage based on the site, and then turning observation, if leakage without significant changes in the static, dynamic ring seal problem; such as disk when there are significant changes in leakage can be concluded is dynamic, static friction ring problems; such as the leakage medium along the axial injection, then dynamic ring seal problems are, the leakage medium sprays or from the water cooling hole leakage, mostly static seal ring failure. In addition, leakage passage can also exist at the same time, but in general the primary-secondary distinction, as long as the careful observation, familiar with the structure, can judge correctly.

2 leakage occurs when commissioning. Pump with mechanical seal after static test, the operation of high-speed rotation of the centrifugal force generated, can inhibit the leakage of media. Therefore, when the mechanical seal leakage test run in the exclusion of shaft and the end cover sealing failure, basically are due to dynamic, static friction ring caused by the destruction. Cause friction sealing failure are the main factors:
( L ) operation, because of time, cavitation, such as hold pressure anomaly, the axial force caused by the larger, so that dynamic, static ring contact surface separation;
( 2) the installation of mechanical seal when compressed amount is too large, resulting in friction face serious wear, abrasion;
( 3) dynamic tight ring seals, spring can not adjust the axially movable ring float;
( 4) static seal ring too loose, when the dynamic axial floating ring, a static ring from a static ring seat;
( 5) the working medium in the granular material, into the functioning of friction, dynamic testing, static seal face;
( 6) design and selection is not correct, the low pressure end seal or sealing material such as shrinkage of the larger. The above phenomena in the test run frequently, sometimes it is possible to adjust the static ring seat to be eliminated, but the majority of the need to disassemble, replace the seal.

3 normal operation all of a sudden leakage. Centrifugal pump in operation all of a sudden leak a few because of normal wear and tear, or has reached the useful life, while the majority is due to large changes in operating conditions, caused by improper maintenance or operation.
( 1) time, or a longer period of time cavitation hold pressure, resulting in seal damage;
( 2) of the actual pump output too small, a large number of medium circulation pump, heat accumulation, caused by gasification medium, resulting in seal failure;
( 3) large back flow, leading to inhalation tube side of the container ( tower, kettle, pot, pool ) at the bottom of the surface sediment, damage to seal;
( 4) for a longer period of time to shutdown, restart without manual jigger, friction due to adhesion and brought bad sealing surface;
( 5) medium corrosion, polymerization, node number of plastic substances;
( 6) the environment temperature variation;
( 7) cases frequently change or adjustment;
( 8) a sudden power failure or breakdown. In the normal operation of centrifugal sudden leakage, if not in time, will often lead to an accident or loss of the larger, should be seriously and take effective measures.