What Is a Hand-Operated Valve?
Compressed air is used as a power source in various production equipment such as machine tools, conveying equipment, and inspection equipment.
Compressed air is sent to production equipment, which drives air cylinders to transport products, robots to clamp products, and air blowers to clean products.
Hand-operated valves are devices that allow operators to manually change airflow direction in piping or air tubes, stop air flow, or adjust the flow rate using a lever or handle for switching.
Uses of Hand-Operated Valves
Hand-operated valves are used for the following applications:
- Speed control of conveying equipment
- Equipment (loaders, shifters, etc.) that removes products from machine tools and transfers them to subsequent processes may cause products to fall or shift position due to vibration if the transfer speed is too fast.
- The airflow rate can be adjusted with hand-operated valves to change the speed without causing problems.
- Switching valve for interchangeable jigs
- Jigs may be replaced when changing models in equipment that processes a variety of products.
- The air hose must be disconnected and replaced for jigs with air cylinder clampers.
- Air leaks can be prevented by stopping the air supply to the jig with the switching valve and then disconnecting the hose.
Features of Hand-Operated Valves
There are various types of hand-operated valves, each with distinct features:
Residual Pressure Relief Valve
- When production equipment is stopped during a process due to an abnormality, it is dangerous to take action while air pressure remains in the equipment.
- The cylinder may become unhooked for some reason and suddenly recoil, possibly injuring the operator.
- For this reason, hand-operated valves for releasing residual pressure can be attached to the piping route so that safe measures can be taken after removing the residual pressure.
Directional Changeover Valve
- This valve changes the direction of airflow to alter the operation of equipment.
- The airflow direction is indicated on the lever handle attached to the valve body.
- For example, in inspection equipment that supplies clean air, filters need to be cleaned periodically, but production will be halted if the equipment cannot be operated during cleaning.
- Two filters can be installed in parallel circuits, and a directional valve can select the circuit that is not being cleaned, allowing cleaning without stopping production.
- A screw-type knob is attached to the valve body, and as the knob is tightened, the airflow path inside the valve is gradually restricted, thereby reducing airflow through the valve.