Datasheet

Mounting
Warning
Selection
AC/Class B built-in full-wave rectifier coil: 10% or less of
rated voltage
DC coil: 2% or less of rated voltage
Caution
1. Leakage voltage
Particularly when using a resistor in parallel with a switching
element and using a C-R element (surge voltage suppressor)
to protect the switching element, take note that leakage
current will flow through the resistor, C-R element, etc.,
creating a possible danger that the valve may not turn off.
2. Selecting model
Material depends on fluid. Select optimal models for the fluid.
3. When the fluid is oil.
The kinematic viscosity must not exceed 50 mm
2
/s.
1. If air leakage increases or equipment does not
operate properly, stop operation.
After mounting is completed, confirm that it has been done
correctly by performing a suitable function test.
2. Do not apply external force to the coil section.
When tightening is performed, apply a wrench or other tool to
the outside of the piping connection parts.
3. Mount a valve with its coil position upward, not
downward.
When mounting a valve with its coil positioned downward,
foreign objects in the fluid will adhere to the iron core leading
to a malfunction. Especially for strict leakage control, such as
with vacuum applications and non-leak specifications, the coil
must be positioned upward.
4. Do not warm the coil assembly with a heat insulator,
etc.
Use tape, heaters, etc., for freeze prevention on the piping and
body only. They can cause the coil to burn out.
5. Low temperature operation
1) The valve can be used in an ambient temperature of between
–20 to –10°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.
Warning
R
SOL.
OFF
Switching element
C
Power supply
Leakage voltage
Leakage current
Selection
Warning
<Water>
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.
The supply water includes materials that create a hard
sediment or sludge such as calcium and magnesium.
Sediment and sludge can cause the valve to not operate
properly. Therefore, install a water softening device, which
removes these materials, and a filter (strainer) directly in front
of the valve.
Tap water pressure:
The water pressure for tap water is normally 0.4 MPa or less.
However, in places like a high-rise building, the pressure may
be 1.0 MPa. When selecting tap water, be careful of the maxi-
mum operating pressure differential.
When using water or heated water, poor operation or leaks
may be caused by dezincification, erosion, corrosion, etc.
The brass (C37) body of this product uses dezincification-
resistant material as a standard. We also offer a stainless
steel body type with improved corrosion resistance. Please
use the one that fits your needs.
<Oil>
Generally, FKM is used as seal material, as it is resistant to
oil. The resistance of the seal material may deteriorate
depending on the type of oil, manufacturer or additives.
Check the resistance before using. The kinematic viscosity
must not exceed 50 mm
2
/s
<Steam>
The use of a steam 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 standard, the mesh count for the strainer is 100 mesh.
However, the size and shape of foreign objects that occur
depends on the operating environment. Check the fluid
status and choose an appropriate mesh count.
The supply water to a boiler includes materials that create a
hard sediment or sludge such as calcium and magnesium.
Sediment and sludge from steam can cause the valve to not
operate properly. Install a water softening device, which
removes these materials. Do not use operation steam which
contains chemicals, synthetic oils containing organic
solvents, salts or corrosive gases, etc., as these can cause
damage or deterioration.
3. 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.
4. Countermeasures against static electricity
Take measures to prevent static electricity since some fluids
can cause static electricity.
Series VX21/22/23
Specific Product Precautions 2
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
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