How to correct and reasonable selection of lining of ceramic valves has always been very concern of the chemical industry and chemical industry design institute, there are dense company of ceramics of technology department according to the customers for many years field application experience, put forward the following matters needing attention for how to choose the lining ceramic valve, for your reference.
Lined ceramic valve in the petroleum, chemical industry, medicine, metallurgy, electric power industries strong corrosive medium such as acid-base device, has been widely used, but on how to choose the right, with a good lining of ceramic valves, many users unit was not very understanding, based on our thousands of users over the years field application experience, the transform ceramic valve selection, user unit dealing with medium temperature, pressure, pressure conditions of use pay attention to the following items:
1. The lining of ceramic valves use medium conditions unfavorable are hard particles, crystallization, impurities and so on, in order to avoid the valve in the open and closed torn in the operation of the valve core, the seat four ceramic lining of ceramic layer or bellows.Of medium hard particles, crystallization, impurities, when selected, valve core and valve seat can convert ceramic lining.
2. The lining of ceramic valves use medium temperature: my company's all kinds of lining of ceramic valve, ceramic plastic PTFE, using the medium temperature should not exceed 150 ℃ (medium to short time to a temperature of 180 ℃), otherwise, the valve components of PTFE lining of softening, deformation, the valves are closed tightly, big leakage.If use the medium temperature under 180 ℃ temperature for short periods of time, temperature under 160 ℃ for a long time, can choose another ceramic plastic - PFA, but plastic lining PFA ceramics than PTFE lining some more expensive in price.
3. Pressure, differential pressure should be controlled within the scope of the permit.Especially bellows seal lined ceramic regulator, lining of ceramic globe valve.For corrugated pipe is made of four ceramic material, pressure, differential pressure big, easy to cause the corrugated pipe burst.Bellows seal lined ceramic valve, use conditions of pressure, differential pressure big, can be changed to four ceramic packing seal.
4. Lined ceramic valve should be properly according to the flow (Cv) of the need to use valve size.When choose, should according to the need of traffic (Cv) and other technical parameters are calculated lined ceramic valve should choose the size and the opening of the valve, such as valve's size too big, is bound to make the valve in the case of small opening operation for a long time, and a medium pressure, so easy to make valve core and valve rod by the impact of the media and make the valve vibrates, valve core rod under the impact of the media for a long time, may even make stem fracture.When users choose all kinds of ceramic valves lining, should as far as possible the understanding, to master the use of technical conditions, in order to choose the right, with good, improve the service life of the valve.When meeting exceed the scope of use of technical conditions, shall be made to manufacturers and joint consultation, take corresponding countermeasures to solve.
5. According to the size of the size, don't be overly negative pressure.Lining of ceramic valves should avoid to use pipes with negative pressure, such as negative pressure, the body is easy to cause the lining of ceramic layer was sucked out (drum), shell, lead to the valve opening and closing down.