Datasheet
Pressure Terminology
1. Maximum operating pressure differential
The maximum pressure differential (the difference between 
the inlet and outlet pressure) which is allowed for operation. 
When the outlet pressure is 0 MPa, this becomes the 
maximum operating pressure.
2. Minimum operating pressure differential
The minimum pressure differential (the difference between the 
inlet pressure and outlet pressure) required to keep the main 
valve fully opened.
3. Maximum system pressure
The maximum pressure that can be applied inside the 
pipelines (line pressure).
[The pressure differential in the solenoid valve portion must be 
less than the maximum operating pressure differential.]
4. Withstand pressure
The pressure in which the valve must be withstood without a 
drop in performance after holding for one minute under 
prescribed (static) pressure and returning to the operating 
pressure range. [value under the prescribed conditions]
Others
1. Material
NBR: Nitrile rubber
FKM: Fluoro rubber – Trade names: Viton
®
, Dai-el
®
, etc.
2. Oil-free treatment
The degreasing and washing of wetted parts
3. Passage symbol
In the JIS symbol ( ) IN and OUT are in a blocked condi-
tion( ), but actually in the case of reverse pressure (OUT>IN), 
there is a limit to the blocking.
Electrical Terminology
1. Surge voltage
A high voltage which is momentarily generated by shutting off 
the power in the shut-off area.
2. Enclosure
A degree of protection defined in the “JIS C 0920: Waterproof 
test of electric machinery/appliance and the degree of protec-
tion against the intrusion of solid foreign objects.”
Verify the degree of protection for each product.
Faston Terminal
1. Faston
TM
 is a trademark of Tyco Electronics Corp.
2. For electrical connection of the Faston terminal and 
molded coil, please use Tyco’s “Amp/Faston 
connector/250 Series” or the equivalent.
Example) IP65: Dust-tight, Water-jet-proof type
“Water-jet-proof type” means that no water intrudes inside 
an equipment that could hinder from operating normally by 
means of applying water for 3 minutes in the prescribed 
manner. Take appropriate protection measures, since a 
device is not usable in an environment where a droplet of 
water is splashed constantly.
Second characteristic numeral
IP
First characteristic numeral
 First Characteristics:
 Degrees of protection against solid foreign objects
0
1
2
3
4
5
6
Non-protected
Protected against solid foreign objects of 50 mmø and greater
Protected against solid foreign objects of 12 mmø and greater
Protected against solid foreign objects of 2.5 mmø and greater
Protected against solid foreign objects of 1.0 mmø and greater
Dust-protected
Dust-tight
 Second Characteristics:
 Degrees of protection against water
0
1
2
3
4
5
6
7
8
Non-protected
Protected against vertically falling water drops
Protected against vertically falling water drops when enclosure tilted up to 15°
Protected against rainfall when enclosure tilted up to 60°
Protected against splashing water
Protected against water jets
Protected against powerful water jets
Protected against the effects of temporary immersion in water
Protected against the effects of continuous immersion in water
Dripproof type 1
Dripproof type 2
Rainproof type
Splashproof type
Water-jet-proof type
Powerful water-jet-proof type
Immersible type
Submersible type
—
Series VX21/22/23
Glossary of Terms
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