VP31
∗
5 Series
3 Port Solenoid Valve
Precautions 2
Be sure to read this before handling products.
Design/Selection
6. External pilot type
Use external pilot operated style valve for air blowing
applications. Supply compressed air defined by specifications
for the port of the external pilot. When the pressure at IN port
side drops more than 0.2MPa on switching the valve, the valve
will cause operation failure, so use the external pilot type (in
case the valve is used with IN port restricted or OUT port
opened to the atmosphere or the almost same condition as
OUT port).
7. Mounting orientation
Mounting orientation is not specified.
8. Initial lubrication of main valve
Grease has been applied to the main valve as initial lubricant.
9. Pilot EXH. (PE) port
If the pilot EXH. (PE) port of the solenoid valve is significantly
restricted or blocked, the valve operation may become
abnormal.
Mounting
1. Operation manual
Install the products and operate them only after reading the
operation manual carefully and understanding its contents.
Also, keep the manual where it can be referred to as
necessary.
2. Ensure sufficient space for maintenance
activities.
When installing the products, allow access for maintenance
and inspection.
3. Tighten threads with the proper tightening
torque.
When installing the products, follow the listed torque
specifications.
4. If air leakage increases or equipment does not
operate properly, stop operation.
Check mounting conditions when air and power supplies are
connected. Initial function and leakage tests should be
performed after installation.
5. Painting and coating
Warnings or specifications printed on or affixed to the product
should not be erased, removed, or covered up.
Please consult with SMC before applying paint to resinous
parts, as this may have an adverse effect due to the solvent in
the paint.
Piping
1. Preparation before piping
Before piping is connected, it should be thoroughly blown out
with air (flushing) or washed to remove chips, cutting oil, and
other debris from inside the pipe.
2. Winding of sealant tape
When screwing piping or fittings
into ports, ensure that chips
from the pipe threads or sealing
material do not enter the piping.
Also, if sealant tape is used,
leave 1 thread ridge exposed at
the end of the threads.
3. Connection of fittings
When using a fitting other than an SMC fitting, follow the
instructions given by the fitting manufacturer.
1) For a fitting with sealant R or NPT, first, tighten it by hand,
then use a suitable wrench to tighten the hexagonal portion
of the body an additional two or three turns. For the
tightening torque, refer to the table below.
Connection thread size
(R, NPT)
Proper tightening torque
(N·m)
1/4
8 to 12
3/8
15 to 20
1/2
20 to 25
3/4
28 to 30
1
36 to 38
1 1/4
40 to 42
1 1/2
48 to 50
2
48 to 50
2) If the fitting is tightened with excessive torque, a large
amount of sealant will seep out. Remove the excess
sealant.
3) Insufficient tightening may cause seal failure or loosen the
threads.
4) For reuse
(1) Normally, fittings with a sealant can be reused up to 2 to
3 times.
(2) To prevent air leakage through the sealant, remove any
loose sealant stuck to the fitting by blowing air over the
threaded portion.
(3) If the sealant no longer provides effective sealing, wind
sealing tape over the sealant before reusing. Do not use
any form of sealant other than the tape type of sealant.
(4) Once the fitting has been tightened, backing it out to its
original position often causes the sealant to become
defective. Air leakage will occur.
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No.VP3145-OMM0002-B
