SMC Networks VEX3 Series Operation Manual page 5

VEX3 Series
3 position valve with 3 ports / Precautions (1)
Be sure to read before handling.
Design/Selection
Warning
1. Confirm the specifications.
This product is designed only for use in compressed air systems
including vacuum.
Do not operate at pressures or temperatures, etc., beyond the
range of specifications, as this can cause damage or malfunction.
(Refer to the specifications.)
Please contact SMC when using a fluid other than compressed
air (including vacuum).
We do not guarantee against any damage if the product is used
outside of the specification range.
2. Actuator drive
When an actuator, such as a cylinder, is to be driven using a
valve, take appropriate measures (cover installation or approach
prohibition) to prevent potential danger caused by actuator
operation.
3. Intermediate stops
Due to the compressibility of air, it is difficult for this product to
make a piston stop at the required intermediate position
accurately and precisely.
Furthermore, since valves and cylinders are not guaranteed for
zero air leakage, it may not be possible to hold a stopped position
for an extended period of time.
Please contact SMC if it is necessary to hold a stopped position
for an extended period of time.
4. Effect of back pressure when using a manifold
Use caution when valves are used on a manifold, because an
actuator may malfunction due to back-pressure.
5. Holding pressure (including vacuum)
Since the valves are subject to air leakage, they cannot be used
for applications such as holding pressure (including vacuum) in a
pressure vessel.
6. Not suitable for use as an emergency shutoff
valve, etc.
This product is not designed for safety applications such as an
emergency shutoff valve. If the valves are used for the mentioned
applications, additional safety measures should be adopted.
7. Release of residual pressure
For maintenance purposes install a system for releasing residual
pressure.
Ensure that the residual pressure between the valve and the
cylinder is released.
8. Operation in a vacuum condition
When a valve is used for switching a vacuum, take measures to
install a suction filter or similar to prevent external dust or other
foreign matter from entering inside the valve.
In addition, at the time of vacuum adsorption, be sure to vacuum
at all times. Failure to do so may result in foreign matter sticking
to the adsorption pad, or air leakage causing the workpiece to
drop.
9. Use of the VEX3 series solenoid type product
When using the VEX3 series solenoid type for the first time,
actuators may travel in an unexpected direction depending on the
switching position of the valve. Implement measures to prevent
any danger from occurring when operating the actuator.
10. Ventilation
Provide ventilation when using a valve in a confined area, such
as in a closed control panel. For example, install a ventilation
opening, etc. in order to prevent pressure from increasing inside
of the confined area and to release the heat generated by the
valve.
11. Extended periods of continuous energization
• If a valve will be continuously energized for an extended period of
time, the temperature of the valve will increase due to the heat
generated by the coil. This will likely adversely affect the
performance of the solenoid valve and any nearby peripheral
equipment. Therefore, when it is continuously energized for an
extended period of time or when the energized period per day is
longer than the de-energized period, use VEX3 air operated type
product. For pilot air operation, use a low-wattage type or
continuous duty type valve.
As a valve not mentioned above can also be used depending on
the operating conditions (in particular,DC specification valves),
please contact SMC for further information.
• For applications such as mounting a valve on a control panel,
incorporate measure to limit the heat radiation so that it is within
the operating temperature range. Do not touch the valves by bare
hand during or after energization.
In particular, note that the temperature rise will be greater if the
product is energized for extended periods of time.
12. Do not disassemble the product or make any
modifications, including additional machining.
It may cause human injury and/or an accident.
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