Water ring vacuum pump is compact in structure, reliable in working balance and uniform in flow. It is mainly used to transport or pump flammable, explosive and corrosive gases in chemical production. The efficiency of water ring vacuum pump is very low because of the loss of energy due to impeller stirring liquid. After using water ring vacuum pump for a period of time, we need to carry out certain maintenance. Among them, the maintenance of the cylinder is particularly important. The cylinder is formed by the space between two adjacent blades. The relative rotation moves, and the water moves up and down along the blade like a piston. Measure the roundness and cylindricity of the cylinder of water ring vacuum pump, and determine whether to bore or replace the cylinder according to its wear degree; the roundness and cylindricity of the cylinder shall meet the relevant regulations; the inner surface of the cylinder shall be free of defects such as cracks, sand holes, scars and grooves, and the surface roughness shall be 1.6; the water jacket of the cylinder shall not have cracks or leakage and other defects; the diameter of the cylinder after hammering the water ring vacuum pump shall not exceed the original The thickness of the cylinder wall should not exceed 1 / 12 of the original wall thickness. Correct maintenance of water ring vacuum pump cylinder will be more conducive to the use of the pump, but also to extend its life and improve the use efficiency.

There are two reasons for this phenomenon: water ring vacuum pump itself has a fault or due to the poor sealing of the pipeline system and gas leakage. In order to determine the cause of the fault, for the vacuum pump, cut off the suction system pipe, connect the inlet pipe of the water ring vacuum pump directly with the closed container for test, and for the compressor, cut off the pipeline of the compression system and connect the exhaust pipe of the pump directly with the closed container for test.

After the pump is connected with the closed container, start the water ring pump. If the pressure and vacuum do not change after 15 ~ 20 minutes, it indicates that the pump itself has a fault. If the pressure and vacuum gradually increase and reach the normal value, it indicates that the pipeline system is not well sealed and even leaks gas. If the pressure and vacuum degree are higher than before, but can not reach the normal value, it means the pump And the piping system. A simple test method in the field is: close the valve close to the suction port (for vacuum pump) or exhaust pipe (for compressor), start the water ring pump, and observe the change of vacuum gauge near the suction port or the pressure gauge of exhaust pipe, so as to find out the cause of failure. In this way, the reliability of valve sealing must be ensured.

If the problem is in the piping system, the leak can be found by pressurizing the pipe. The test can be carried out at 1.5-3 atmospheres. After tightening all the connecting bolts, coat the places prone to air leakage with soap solution, such as flange, threaded connection, welding joint and the places with air holes and cracks on the pipe. If these areas leak, the soap solution will produce large bubbles. For places with little air leakage, shellac (i.e. foreign dry paint), benzene resin paint, putty and other mortar or paint can be used to coat the air leakage. However, these are temporary emergency measures. The reliable and long-term method is to braze the metal at the leaking place. For places with large air leakage, it is better to replace them with new parts. If the condition is not allowed, repair measures must be taken. The place of air leakage often occurs at the flange connection of the pipe, and the candle can be close to the joint. If the candle is absorbed to the joint or shakes indefinitely, it indicates that there is air leakage. Because the connecting bolts have been tightened before the test, this kind of air leakage indicates that the gasket has been damaged or the number is not correct, so the gasket must be replaced or the thickness of the gasket must be adjusted.