Answers to common valve selection questions

Q: Which one should I choose among pneumatic valve, electric valve and solenoid valve?

A: In general situations, if there is an air source on site (air source pressure is more than 3kg), it is recommended to choose pneumatic valve as much as possible. The switching frequency of electric valve is relatively low. If it is opened continuously, the motor will burn. The motor will automatically stop when it overheats. The disadvantage of electric valve is that the control time is relatively slow, so if the switching frequency is relatively high, it is not recommended to choose electric valve.

Q: The medium is water. Which is better for anti-corrosion medium, stainless steel or lining?

A: In terms of selection, it depends on the material of the pipeline. Generally, if the pipeline is 304, it is no problem to choose a 304 ball valve. If it is a 316 pipeline, then choose a 316 ball valve or solenoid valve. If there is corrosion, it depends on the corrosiveness and the types of chemical elements. If the medium is water, it also depends on the pressure of the pipeline.

Q: Which one is better, wafer or flange?

A: It is usually recommended that customers choose a wafer. Both wafer and flange need flanges to connect. From a cost perspective, wafer is more affordable. The use of flanges and wafer is not much different.

Q: How to increase the life of a large-diameter valve if the opening needs to be controlled in a normally open state for a long time? Or choose a model?

A: There is no saying that the life can be increased. If a product reaches the end of its life, you can choose to replace the seal. The relative linearity of ball valves and butterfly valves is the same, both are equal percentage linear, and the flow opening is not very different. It is generally better to choose a butterfly valve if it is not fully opened for a long time. If it is a very clean medium such as water or gas, you can choose a soft-sealed butterfly valve. If there is mud and sand, if the cost allows, it is recommended to choose a hard-sealed butterfly valve. Butterfly valves are divided into soft seals and hard seals. The service life of large-diameter hard seals will be longer, generally about 30,000 times, and soft seals are generally about 10,000 times. If you want to extend the life, you can only replace the seal.

Q: Which valve is more suitable for pipelines with high air tightness?

A: For pipelines with high air tightness, choose ball valves or vacuum ball valves. Vacuum butterfly valves are special. If it is a one-way seal with a large diameter, choose a vacuum butterfly valve, and if it is a small diameter, choose a vacuum ball valve. 50 or more is a large diameter, and 50 or less is a small diameter. It depends on your system and budget cost. If the budget cost is high, try to choose a ball valve.

Q: How long can the underwater extension rod valve be extended?

A: Generally, it depends on the on-site situation, how large the diameter is, whether the medium can be driven, and how much the torque changes.

Q: For high-temperature water, can stainless steel be selected for the valve material?

A: It depends on how high the water temperature is. It can be no more than 100 degrees. Cast steel and stainless steel are both fine. Pay attention to seawater. The material of seawater must be 316 stainless steel or above.

Q: Solenoid valve, if the medium is methyl chloride

A: There is a situation where methyl chloride pneumatics cannot crystallize, cannot become crystals, and do not produce chlorine scale (in some chlorine gas occasions, some chlorine scale will be produced after selecting a solenoid valve).