1. Cannot be used as an emergency shutoff valve, etc. The valves presented in this catalog are not designed for safety applications such as an emergency shutoff valve. If the valves are used in this type of system, other reliable safety assurance measures should also be adopted. 2. Extended periods of continuous energization The solenoid coil will generate heat when continuously energized. Avoid using in a tightly shut container. Install it in a wellventilated area. Furthermore, do not touch it while it is being energized or right after it is energized. 3. This solenoid valve cannot be used for explosion proof applications. 4. Maintenance space The installation should allow sufficient space for maintenance activities. 5. Actuator drive When an actuator, such as a cylinder, is to be driven using a valve, take appropriate measures to prevent potential danger caused by actuator operation. 6. Use caution regarding exhaust port freezing. If a high pressure air (more than 1.0 MPa) is quickly exhausted, there may be an occurrence in which the valve will not switch properly or the service life will substantially decrease due to condensation or freezing caused by the substantial temperature change. When condensation or freezing occurs, take measures such as using a freeze-reducing silencer (VCHNF series), etc. 7. Use caution regarding back pressure. 1) When port 3 (EXH) of a 3 port solenoid valve (VCH400 series) is excessively throttled or used as a selector valve (pressurizing 1, 3 port), the pressure in the port should be within a range of half the pressure in port 1 (port 1 pressure = twice as strong as port 3 pressure). Using a 3 port valve beyond its back pressure and/or supply pressure range may cause the valve switch to malfunction or result in unstable operation. 2) In the case of a 3 port solenoid valve, when the valve is being switched, a high pressure air will be introduced into the lower pressure side. Therefore, when using this product as a selector valve for switching a high and medium pressure, a relief type regulator (VCHR series) must be used for the medium pressure side. Design Warning 1. Confirm the specifications. Give careful consideration to the operating conditions such as the application, fluid and environment, and use within the operating ranges specified in this catalog. 2. Fluid Corrosive gas Cannot be used since it will lead to cracks by stress corrosion or result in other incidents. 3. Air quality 1) Use clean air. Do not use compressed air which includes chemicals, synthetic oils containing organic solvents, salt or corrosive gases, etc., as it can cause damage or malfunction. 2) Install air filters. Install air filters close to valves at their upstream side. A filtration degree of 5 μm or less should be selected. 3) Install an air dryer or after-cooler, etc. Compressed air that includes excessive drainage may cause malfunction of valves and other pneumatic equipment. To prevent this, install an air dryer or after cooler, etc. 4) If excessive carbon powder is generated, eliminate it by installing mist separators at the upstream side of valves. If excessive carbon powder is generated by the compressor, it may adhere to the inside of the valves and cause a malfunction. Refer to Best Pneumatics No. 5 for further details on compressed air quality. 4. Ambient environment Use within the operable ambient temperature range. Confirm the compatibility between the product’s composition materials and the ambient atmosphere. Be sure that the fluid used does not touch the external surface of the product. 5. Supply source If the primary side air is throttled, flow may be reduced resulting in the malfunction of the switch or instability in the response time because of the pilot operated solenoid valve. Conduct piping work suited for the secondary side piping (air consumption). Also, when a regulator is installed, the air supply will stop right after the solenoid valve is switched due to the response time of the regulator. Thus, when using it below the minimum operating pressure, adjust the pipe size, length or provide an air tank, etc. Warning Selection 5.0 MPa Pilot Operated 2/3 Port Solenoid Valves & Check Valves Precautions 1 Be sure to read this before handling. = > 368