VT325 Series
3 Port Solenoid Valve
Precautions 1
Be sure to read this before handling products.
Design/Selection
1. Confirm the specifications.
This product is designed only for use in compressed air
systems (including vacuum). Do not operate at pressures,
temperatures, etc., beyond the range of specifications, as this
can cause damage or malfunction. (Refer to the catalog)
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 (such as the installation of a
cover or the restricting of access to the product) to prevent
potential danger caused by actuator operation.
3. Effects of back pressure when using a
manifold
Use caution when valves are used on a manifold because
actuators may malfunction due to back pressure.
When a single acting cylinder is operated, take appropriate
measures to prevent malfunction by using an individual
exhaust manifold.
4. Holding pressure (including vacuum)
Since valves are subject to air leakage, they cannot be used
for applications such as holding pressure (including vacuum)
in a pressure vessel.
5. Not suitable for use as an emergency shutoff
valve, etc.
The valves presented in this catalog are not designed for
safety applications (e.g. emergency shutoff valve). If the valves
are used in such applications, additional safety measures
should be adopted.
6. Release of residual pressure
For maintenance and inspection purposes install a system for
releasing residual pressure.
7. 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
supply a constant supply of vacuum. Failure to do so may
result in foreign matter sticking to the adsorption pad or air
leakage, causing the workpiece to drop.
8. Regarding vacuum switch valves and vacuum
release valves
If a non-vacuum valve is installed in the middle of a piping
system that contains a vacuum, the vacuum condition will not
be maintained. Use a valve designed for use under vacuum
conditions.
9. 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.
10. Extended periods of continuous energization
Caution for high temperature
∗
The surface temperature of the valve may increase.
● 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 assembly. 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 a continuous duty type valve.
Depending on the operating conditions, it may be possible to
use other valves than the ones mentioned above. Please
contact SMC for further information.
Additionally, the use of a valve with N.O. (normally open)
specificationsmakes it possible to shorten the energizedtime.
● When the valve is mounted onto a control panel, take
measures against heat radiation in order to keep the valve
temperature within the specified range.
In particular, note that the temperature rise will be larger if three
or more adjacent valves on the manifold are energized together
for extended periods of time.
11. Do not disassemble the product or make any
modifications, including additional machining.
Doing so may cause human injury and/or an accident.
1. Leakage voltage
Take note that the leakage voltage will increase when a
resistor is used in parallel with a switching element or when a
C-R circuit (surge voltage suppressor) is used for protecting a
switching device because of the leakage voltage passing
through the C-R circuit. The suppressor residual leakage
voltage should be as follows.
DC coil
2% or less of the rated voltage
AC coil
15% or less of the rated voltage
2. Solenoid valve drive for AC with a solid state
output (SSR, TRIAC output, etc.)
1) Current leakage
When using a snubber circuit (C-R element) for surge
protection of the output, a very small amount of electrical
current will continue to flow even during the OFF state.
This results in the valve not returning. In a situation where
the tolerance is exceeded, as in the above case, take
measures to install a bleeder resistor.
2) Minimum allowable load amount (Min. load current)
When the consumption current of a valve is less than the
output’s minimum allowable load volume or the margin is
small, the output may not switch normally. Please contact
SMC.
- 4 -
No.VT325
∗∗
-OMK0002-B
