There are different types of pneumatic valves available in the market similar to the directional control valve. But you have to carefully choose among them and select the right type of pneumatic directional control valve depending upon your requirement. Each valve has its own specific functions. Thus, it is important to understand the basic differences between them and choose accordingly. There are some factors which you should consider while choosing a pneumatic valve and we have made a list of some of those.
The first thing which you need to know is the type of gas or liquid which will be controlled by the pneumatic valve. You should also consider the input pressure, compressed air, negative pressure, air, gas, water,and all the other materials which will be involved along with this valve. Also, you should check whether the valve and the media are compatible with each other and the pressure which is passing through it.
Method of Valve Actuation
In order to open or close a valve, there are a variety of methods. Some of the common ones include solenoid operated, manually operated, mechanically operated or remote air operated. The sources may be an electrical current, skilled labor, lever, foot peddle, cam, plunger or an output signal of another valve.
Spring-Return or Detent Actuation
This is the method of the valve to return back to its unactuated state. Generally, this is either a mechanical spring or maybe a different form of the same actuation method. The manufacturers also know these methods namely as spring return and detent valve types. You need to consider if you would want the valve to return back to its original position or stay in its last position after the actuation.
The pneumatic direction valves could either be 2-way, 3-way or 4-way. These are counted by their active media ports. The 2-way valves have a single inlet and outlet port. Upon actuation, they allow the media to pass through or stop the flow totally. The 3-way valves have a third port in addition to the inlet and the outlet port. When the inlet port is blocked, the third port allows venting of the pressure often outlet port.
The 3-way valves could be either normally closed or normally open. The 4-way outlet adds a second outlet, which acts as the second exhaust port to the 3-way function. They are used for controlling the double-acting pneumatic cylinders and actuators. The inlet pressure in these valves switches from one outlet port to the other.
Consider these factors while choosing pneumatic valves.