VP31
∗
5 Series
3 Port Solenoid Valve
Precautions 3
Be sure to read this before handling products.
Piping
4. Uni thread fittings
1) First, tighten the threaded portion by hand, then use a
suitable wrench to tighten the hexagonal portion of the body
further at wrench tightening angle shown below. For the
reference value for the tightening torque, refer to the table
below.
Connection Female Thread: Rc, NPT, NPTF
Uni thread size
Wrench tightening angle
after tightened by hand
(deg)
Tightening torque
(N·m)
1/4
30 to 60
8 to 12
3/8
15 to 45
14 to 16
1/2
15 to 30
20 to 22
Connection Female Thread: G
Uni thread size
Wrench tightening angle
after tightened by hand
(deg)
Tightening torque
(N·m)
1/4
15 to 30
4 to 5
3/8
15 to 30
8 to 9
1/2
15 to 30
14 to 15
2) The gasket can be reused up to 6 to 10 times. It can be
replaced easily when it has sustained damage. A broken
gasket can be removed by holding it and then turning it in
the same direction as loosening the thread. If the gasket is
difficult to remove, cut it with nippers, etc. In such a case,
use caution not to scratch the seat face because the seat
face of the fitting’s 45° gasket is the sealing face.
5. Piping to products
When connecting piping to the product, refer to the catalog to
avoid mistakes regarding the supply port, etc.
Wiring
1. The solenoid valve is an electrical product.
For safety, install an appropriate fuse and
circuit breaker before use.
1. Polarity
No +/- polarity for this solenoid valve.
2. Applied voltage
When electric power is connected to a solenoid valve, be
careful to apply the proper voltage. Improper voltage may
cause malfunction or coil damage.
3. Check the connections.
Check if the connections are correct after completing all
wiring.
4. External force applied to the lead wire
If an excessive force is applied to the lead wire, this may
cause faulty wiring. Take appropriate measures so that a force
of 30 N or more is not applied to the lead wire.
Lubrication
This is a valve which requires lubrication. Be
sure to lubricate it for operation.
It may cause problems such as damage and
malfunction of the valve if it is not lubricated.
A valve of vacuum specification needs overhaul
for cleaning and addition of grease because it
cannot be lubricated without it. (Refer to page
11.)
1) If a lubricant is used in the system, use class 1 turbine oil (no
additive), ISO VG32.
2) Please contact SMC regarding class 2 turbine oil (with
additives), ISO VG32.
1. Lubrication amount
If too much oil is applied, it may accumulate in the product,
causing malfunction or response delay. So, do not apply a
large amount of oil.
Air Supply
1. Use clean air
Do not use compressed air that contains chemicals, synthetic
oils that include organic solvents, salt, corrosive gases, etc.,
as it can cause damage or malfunction.
1. Install an air filter.
Install an air filter upstream near the valve. Select an air filter
with a filtration size of 5 μm or smaller.
2. Take measures to ensure air quality, such as
by installing an aftercooler, air dryer, or water
separator.
Compressed air that contains a large amount of drainage can
cause the malfunction of pneumatic equipment, such as
valves. Therefore, take appropriate measures to ensure air
quality, such as by providing an aftercooler, air dryer, or water
separator.
3. If an excessive amount of carbon powder is
present, install a mist separator on the
upstream side of the valve.
If excessive carbon dust is generated by the compressor, it
may adhere to the inside of a valve and cause it to
malfunction.
For compressed air quality, refer to the SMC Best Pneumatics
catalog No. 6.
- 6 -
No.VP3145-OMM0002-B
