Analysis of solenoid valve material and basic performance

Analysis of solenoid valve material and basic performance

1. The material of the valve

    In the past, most of the valve materials were gray cast iron, and some were ductile iron. Since the pipes and fittings are made of ductile iron, the material of the solenoid valve should also be the same. In order to improve the quality of castings, and reduce the weight of the valve, especially the valve plate should first use ductile iron.

2. Valve performance and testing

    When evaluating valve performance and performance testing, pay attention to the following points:

    (1) The valve opens and closes flexibly and lightly under the working water pressure, and the opening torque is detected by the torque handle under the working water pressure.

    (2) The valve has a strong flow capacity. Especially for butterfly valves, the flow resistance of the butterfly plate should be small, and the effective area of the flow should be large. This requires that solenoid valves of various calibers and different types should also be tested in a qualified unit to determine the flow resistance coefficient.

    (3) The capacity of the valve body to bear the internal water pressure should be consistent with that of the pipeline, that is, the valve can withstand the requirements of the pipeline test pressure when the valve is open.

    (4) It can test the life, flow resistance and torque of valves with DN≤600mm.

    (5) The valve is closed tightly. Under 11 times the working water pressure, no leakage or dripping meets the requirements of the standard. This requires that both sides of the valve are under pressure in turn, tested separately, and opened and closed multiple times to achieve the same effect.

3. Valve operating mechanism

　　Pipelines are usually buried in the dark. Solenoid valves are protected by wells. Rising stem valves are not suitable. Valve opening and closing must be operated from the ground. Therefore, square tenon caps should be installed at the opening and closing ends of the valve, and handwheels are not suitable. The opening and closing directions are all required to rotate the valve clockwise. The opening and closing degree of the valve should be marked with a dial, which should be observed from the ground. The scale of the dial should be cast on the casting, and can be painted with fluorescent powder for eye-catching. Materials such as aluminum should not be used. The pointer and the scale of the opening and closing limit should be adjusted and locked before installation.

4. Variable speed transmission box of valve　

　　The large-caliber solenoid valve is equipped with a variable speed transmission box due to the opening and closing torque. For such components, the following points should be paid attention to in the manufacture: (1) There is an opening and closing limit device on the box body, and the adjusting nut of this device should be set in the box body.

    (2) The box structure should be as small and firm as possible. If the opening and closing operations are excessive, the box will not be broken.

    (3) The design of the transmission structure is reasonable, and the valve shaft can only be driven to rotate when opening and closing, without making it move up and down; the transmission parts are normally engaged, and there is no separation and slippage when opening and closing with load.　

    (4) Variable-speed transmission boxes are often easily immersed in water in areas with high groundwater levels, so the box body should be sealed. Some valve manufacturers connect the housing of the valve shaft packing with the variable speed transmission box as a whole. Once the packing leaks, it is easy to string into the box. This should be improved.

This article is original by the gas solenoid valve manufacturer, please indicate http://www.sungofluid.com/