Brochure

Series VDW
Specific Product Precautions 1
Be sure to read before handling.
Refer to back cover for Safety Instructions, “Handling Precautions for SMC Products”
(M-E03-3) and the Operation Manual for 2 Port Solenoid Valves for Fluid Control
Precautions. Please download it via our website, http://www.smcworld.com
Design
Warning
Selection
Warning
1. Cannot be used as an emergency shutoff valve, etc.
The valves presented in this catalogue 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 energisation
The solenoid coil will generate heat when continuously
energised. Avoid using in a tightly shut container. Install it in a
well-ventilated area. Furthermore, do not touch it while it is
being energised or right after it is energised.
3. Liquid rings
In cases with a flowing liquid, provide a bypass valve in the
system to prevent the liquid from entering the liquid seal
circuit.
4. 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.
5. Pressure (including vacuum) holding
It is not usable for an application such as holding the pressure
(including vacuum) inside of a pressure vessel because air
leakage is entailed in a valve.
6. When an impact, such as water hammer, etc.,
caused by the rapid pressure fluctuation is applied,
the solenoid valve may be damaged. Give an atten-
tion to it.
Selection
Warning
1. Fluid
1) Type of fluid
Before using a fluid, check whether it is compatible with the
materials of each model by referring to the fluids listed in
this catalogue. Use a fluid with a kinematic viscosity of 50
mm
2
/s or less. If there is something you do not know, please
contact SMC.
2) Flammable oil, Gas
Confirm the specification for leakage in the interior and/or
exterior area.
3) Corrosive gas
Cannot be used since it will lead to cracks by stress
corrosion or result in other incidents.
4) Depending on water quality, a brass body can cause
corrosion and internal leakage may occur. If such abnor-
malities occur, exchange the product for a stainless steel
body.
5) Use an oil-free specification when any oily particle must not
enter the passage.
6) Applicable fluid on the list may not be used depending on
the operating condition. Give adequate confirmation, and
then determine a model, just because the compatibility list
shows the general case.
2. Fluid quality
The use of a fluid that contains foreign objects can cause
problems such as malfunction and seal failure by promoting
wear of the valve seat and armature, and by sticking to the
sliding parts of the armature, etc. Install a suitable filter
(strainer) immediately upstream from the valve. As a general
rule, use 80 to 100 mesh.
When using tap water, since substances such as calcium and
magnesium which generate hard scale and sludge are
included and can cause the valve to malfunction, install water
softening equipment and a filter (strainer) right before the
valve to remove these substances.
3. Air quality
1) Use clean air.
Do not use compressed air that contains chemicals,
synthetic oils including organic solvents, salt or corrosive
gases, etc., as it can cause damage or malfunction.
2) Install an air filter.
Install an air filter close to the valve on the upstream side. A
filtration degree of 5 µm or less should be selected.
3) Install an aftercooler or air dryer, etc.
Compressed air that contains excessive drainage may
cause a malfunction of valves and other pneumatic equip-
ment. To prevent this, install an aftercooler or air dryer, etc.
4) If excessive carbon powder is generated, eliminate it by
installing a mist separator on the upstream side of
valves.
If excessive carbon powder is generated by the compres-
sor, it may adhere to the inside of the valves and cause a
malfunction.
Refer to www.smcworld.com for further details on compressed
air quality.
4. Ambient environment
Use within the operable ambient temperature range. Check
the compatibility between the product’s composition materials
and the ambient atmosphere. Be certain that the fluid used
does not touch the external surface of the product.
5. Countermeasures against static electricity
Take measures to prevent static electricity since some fluids
can cause static electricity.
6. Low temperature operation
1) The valve can be used in an ambient temperature of between
–10 to –20°C. However, take measures to prevent freezing or
solidification of impurities, etc.
2) When using valves for water application in cold climates, take
appropriate countermeasures to prevent the water from
freezing in tubing after cutting the water supply from the
pump, by draining the water, etc. When warming by a heater,
etc., be careful not to expose the coil portion to a heater.
Installation of a dryer, heat retaining of the body is recom-
mended to prevent a freezing condition in which the dew
point temperature is high and the ambient temperature is low,
and the high flow runs.
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