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Gate valve and butterfly valve are used as switches to regulate flow in pipeline. Of course, there are ways to select butterfly valves and gate valves,

In order to reduce the soil cover depth of the pipeline in the water supply network, the butterfly valve is generally selected for the pipeline with large diameter. If the soil cover depth has little impact, the gate valve shall be selected. However, the price of the gate valve with the same specification is higher than that of the butterfly valve. As for the demarcation line of caliber, it should be considered according to the specific situation of each region. In terms of service conditions in recent ten years, the failure rate of butterfly valve is higher than that of gate valve. Therefore, it is worth paying attention to expanding the service range of gate valve when conditions permit.

In recent years, many domestic valve manufacturers have developed and imitated soft seal gate valves, which have the following characteristics compared with the traditional wedge or parallel double gate plate gate valves:

The valve body and bonnet of the soft seal gate valve are cast by the precision casting method. They are formed at one time, basically without machining, and do not use the sealing copper ring, so as to save non-ferrous metals.

There is no pit at the bottom of the soft seal gate valve, no slag is accumulated, and the failure rate of gate valve opening and closing is low.

The soft seal rubber lined valve plate has uniform size and strong interchangeability.

Therefore, the soft seal gate valve will be a form that the water supply industry is willing to adopt. At present, the diameter of soft seal gate valve manufactured in China is 1500mm, but the diameter manufactured by most manufacturers is between 80-300mm. There are still many problems in the domestic manufacturing process. The key component of the soft seal gate valve is the rubber lined valve plate, and the technical requirements of the rubber lined valve plate are high, which can not be achieved by all foreign manufacturers. It is often purchased and assembled from manufacturers with reliable quality.

The copper nut block of domestic soft seal gate valve is embedded above the rubber lined valve plate, which is similar to the structure of gate valve. Due to the active friction of the nut block, the rubber lining of the valve plate is easy to peel off. For the soft seal gate valve of a foreign company, the copper nut block is embedded in the rubber lined gate to form a whole, which overcomes the above shortcomings, but the concentricity of the bonnet and valve body combination is required to be high.

However, when opening and closing the soft seal gate valve, do not close it too tightly, as long as the water stop effect is achieved, otherwise it is not easy to open or peel off the rubber lining. A valve manufacturer used a torsion wrench to control the closing degree during the pressure test of the valve. As a valve operator of a water supply company, he should also follow this method of opening and closing.