Pneumatic Clean Series

3/4/5 Port Solenoid Valve/Common Precautions 1Be sure to read before handling. Refer to pages 7 to 16 of Front matter for safety instructions andcommon precautions for clean series. Refer to the main text for precautions for each series.255WarningDesignqActuator drivingWhen an actuator, such as a cylinder, is to be driven using avalve, take appropriate measures to prevent potential dangercaused by actuator operation.wIntermediate stopWhen the cylinder piston is stopped at an intermediate positionwith a 3 position closed center valve or a perfect valve, it isdifficult, due to air compressibility, to achieve precise andaccurate stop positioning.Since valves and cylinders are not guaranteed for zero airleakage, it may not be possible to hold the stopped position foran extended period of time.Consult SMC if it is necessary to hold the stopped position foran extended period of time.eEffect of back pressure when using a manifoldTake precautions when valves are used on a manifold, asactuator may malfunction due to back-pressure.Special caution is necessary when using a 3 position exhaustcenter valve, or when driving a single acting cylinder, etc. Incases where there is a danger of this kind of malfunction, takecountermeasures by using an individual EXH spacer assembly,or an individual exhaust type manifold, etc.rHolding of pressure (including vacuum)Since valves are subject to air leakage, they cannot be used forapplications such as holding pressure (including vacuum) in apressure vessel.tCannot be used as an emergency shut-off valve.The valves presented in this catalog are not designed for safetyapplications such as an emergency shut-off valve. If the valvesare used in this type of system, other reliable safety assurancemeasures should also be adopted.yMaintenance spaceProvide enough space for maintenance and inspection.uRelease of residual pressureProvide a residual pressure release function for maintenancepurposes. Special consideration should be given to the releaseof residual pressure between the valve and cylinder in the caseof a 3 position closed center type valve.iOperation under vacuum pressureWhen a valve is used for vacuum switching, etc., takemeasures against suction of external dust or othercontaminants from vacuum pads or exhaust ports, etc. Anexternal pilot type valve should be used in this case.Contact SMC in case of an internal pilot type or air operatedvalve, etc.WarningSelectionqConfirm the specifications.The products presented in this catalog are designed only foruse in compressed air systems (including vacuum). Do notoperate at pressures or temperatures out of the specifiedrange, as it can cause damage or malfunction. (Refer tospecifications.)Contact SMC if valves will be continuously energized forextended periods of time.wExtended periods of continuous energizationContact SMC if valves will be continuously energized forextended periods of time.CautionqInstantaneous energizationIf a double solenoid valve will be operated with momentaryenergization, it should be energized for at least 0.1 second.wLeakage voltageParticularly when using a C-Relement (surge voltage suppressor)to protect the switching device,take note that leakage voltagewill increase due to leakagecurrent flowing through theC-R element.Switching deviceC-R elementSuppressor residual voltage leakage should be as follows.In case of DC coilSZ/SY/SYJ: 3% or less of rated voltageSQ/VQ/VQZ/VQD:2% or less of rated voltageIn case of AC coilSQ: 12.5% or less of rated voltageSZ/SY/SYJ: 8% or less of rated voltageVQ/VQZ/VQD: 2% or less of rated voltageeLow temperature operationUnless otherwise specified, valves can be used at temperatureextremes to -10°C. Take appropriate measures to avoidfreezing, drainage of condensation.rOperation for air blowingWhen using solenoid valves for air blowing, an external pilottype or direct solenoid operated type should be used. Also,supply to the external pilot port compressed air within thepressure range prescribed in the specifications.tMounting orientationRubber seal: Refer to the specifications of each series.Metal seal: Mounting orientation of single solenoid is universal.In case of double solenoid or 3 position valves,mount so that the spool valve is horizontal.MountingWarningPowersupplyOFFLeakage currentqIf air leakage increases or equipment does notoperate properly, stop using the valve.After mounting or maintenance, connect compressed air andpower supplies and perform appropriate function and leakageinspections to confirm that the unit has been mounted properly.wInstruction manualsMount and operate the product after reading the manualcarefully and understanding its contents.Also keep the manual where it can be referred to as necessary.eCoatingWarnings or specifications indicated on the product should notbe erased, removed, or covered up. If paint is applied to resinparts, it may have an adverse effect due to the paint solvent.LeakagevoltageValve236