Pneumatic valve is an actuator that uses compressed air to drive the valve. Its opening and closing speed is relatively fast. It is often used for fast two-position cut-off and can also be used to adjust the flow. Since it mainly relies on the air source to perform operations, it has high practicality in flammable and explosive occasions and can be used to control gas, liquid, oil, and various corrosive media. The accessories in pneumatic valves are varied. With different accessories, different control methods can be achieved. Users can make corresponding configurations according to the different working needs of the valve.

Pneumatic triplex

Pneumatic triplex is the most common accessory in pneumatic valves. Its function can be simply summarized as: filtration + pressure reduction + oil mist. Among them, the pressure reducing valve is a must-have accessory. No matter what function the pneumatic valve has, it must be configured. Its function is to give the pneumatic valve a standard power gas source pressure. The standard value is 0.4-0.7MPa.

★ The pressure reducing valve is a valve that reduces the inlet pressure to a required outlet pressure by adjustment, and automatically maintains a stable outlet pressure by relying on the energy of the medium itself.

★ Two-way fittings (filter, pressure reducing valve) function: complete the filtering and pressure reducing functions of compressed instrument air

★ Three-way fittings (filter, pressure reducing valve, oil mist device) function: complete the filtering and pressure reducing functions of compressed instrument air, and lubricate the air.

Pneumatic solenoid valve

Pneumatic solenoid valve, also known as directional control valve, is a necessary configuration for two-way valves that only need to open and close. The solenoid valve controls the opening and closing of the pneumatic valve through excitation/demagnetization. Solenoid valves are often used for switching valves, and control the on and off of the gas source and gas circuit through voltage signals to control the opening and closing of the valve. Definition: A valve that uses an electromagnet to manipulate the movement of the valve core generally realizes the opening and closing of the valve by controlling the movement process of the pneumatic actuator.

Limit switch

Valve limit switch, also known as travel switch, can also be called a reply device. It is a field instrument for detecting the valve status in the automatic control system. It is used to output the open or closed position of the valve as a switch signal (contact), which is received by the program controller or sampled by the computer. After confirmation, the next program is executed. This product can also be used as an interlock protection and remote alarm indication for important valves in the system. If you want to grasp the valve position status of a two-position valve, the valve limit switch is an effective configuration. It is an electrical switch used to indicate and feedback the movement position of mechanical equipment.

Positioner

Valve positioner, which is a necessary configuration for pneumatic control valves. The valve positioner can control the valve position at any opening. It uses the valve stem displacement signal as the input feedback measurement signal and the controller output signal as the setting signal for comparison. When there is a deviation between the two, the output signal to the actuator is changed to make the actuator move, and a one-to-one correspondence between the valve stem displacement times and the controller output signal is established.

Note: If the control valve is controlled by safety conditions, a solenoid valve must also be configured to force the control valve to be in a safe valve position under unexpected circumstances.

For large-capacity cylinder valves, in order to speed up the valve's movement speed, a pilot valve must also be configured. The role of the pilot valve is to drive the pilot valve to switch the pipeline of large volume by the gas signal of small volume, so that the cylinder valve has a faster filling/deflating gas path. There are many types of pilot valves, which should be selected according to the specific needs of the pneumatic valve.

If the valve position to be controlled is a regulating valve, a valve opening transmitter must be installed, which can feedback the valve opening signal at any position. Due to the needs of equipment technology, the valve may be normally open and slowly closed, or slowly open and normally closed, so a pneumatic damper needs to be configured. The damper controls the amount of gas passing through and achieves the required valve movement speed through adjustment.