What kind of valve does the diaphragm valve belong to? How to choose correctly?

The diaphragm valve belongs to the clamp type valve, it is mainly used for opening and closing in the pipeline.

Diaphragm valve has two main advantages: one is that the valve does not need a separate valve stem packing seal structure, diaphragm in the cutting media at the same time played the valve stem sealing function, the other is very flexible diaphragm close reliable, even to the sewage can be done well cut off. Therefore, the control mechanism and the media channel are completely separated, so that the diaphragm valve can not only apply to the food industry and medical and health industry, but also for some difficult to transport media and more dangerous media.

Usually, the use of conditions or the requirements of strict sealing performance, slurry media, wear, light structure, low pressure cut-off (small pressure) to the atmosphere a small amount of leakage, abrasive media recommended selection of diaphragm valve. The diaphragm valve can be used in the case of double adjustment, throttling, channel necking, Low Noise, cavitation and vaporization phenomenon, small torque control. In high temperature medium, high pressure medium, high pressure cut-off (big pressure difference), quick opening and closing action, short structure length of the day does not choose to use diaphragm valve, but the metal diaphragm valve except.

The structural characteristic of the metal diaphragm valve is to clamp a group of thin hemispherical metal films into the valve body as a barrier between the stem and the fluid. Valve closure is achieved by pressing the disc on the seat through the stem head and metal film. The valve is opened through an internal spring, and when the stem is raised and detached from the film, the disc rises. Because the valve stroke is equal to the film's stroke, the valve features a much smaller lift than the general valve. In order to overcome the loss of resistance due to low lift, the seat and the circulation area than the general valve larger, the purpose is to get a greater flow. Because the valve seat is larger, the force is much larger than the usual valve to get enough sealing on the disc because there is no direct contact between the stem and the disc. The disc does not pass through the stem to leave the seat, so the valve is applied to a one-way flow with differential pressure, and usually the media is from the seat below. However, in use should avoid a large number of backflow, so as not to affect the closure of the valve. Generally speaking, it is economical and effective to choose the metal diaphragm valve under high temperature and high pressure, and the diaphragm valve can also be selected in the low temperature and low pressure occasion which does not want to use the synthetic rubber diaphragm valve.

Diaphragm valve installation and maintenance

① diaphragm valve before installation should carefully check whether the operating conditions of the valve and the use of the provisions of the scope of the corresponding, and should be cleaned inside the cavity to prevent dirt blocking or damage to seal parts.

② rubber lining layer and rubber diaphragm surface do not brush grease articles, to prevent rubber swelling, affecting the diaphragm valve service life.

③ handwheel or transmission mechanism, not allowed for lifting, and is strictly prohibited collision.

④ manual operation of the diaphragm valve, should not use the aid of the lever to prevent excessive torque and damage to the driving parts or sealing parts.

⑤ diaphragm valve should be stored in a dry ventilated indoor, is strictly prohibited stacking, inventory of the two ends of the valve channel must be sealed, and the headstock should be in a micro-open state.