Our policy is one of continued research and development. We therefore reserve the right to amend,
without notice, the specifications given in this document. © 2015 Norgren, Inc.
Simplified Valve Circuit Guide
3
Poppet and Spool Valves, 3-way, 3-port
Normally Closed 3-way Valves
When unactuated, block inlet flow and connect the outlet port to the exhaust port. When actuated,
the inlet port is connected to the outlet port and the exhaust port is blocked.
Normally Open 3-way Valves
When unactuated, pass inlet flow to the outlet and block the exhaust port. When actuated, inlet flow
is blocked and the outlet port is connected to the exhaust port.
Except: The normally open configuration is not possible with the 3-way 1/8" Nugget solenoid
operated valve. This valve does not have provisions for an external pilot supply which is required for
"Normally Open" solenoid operated valves.
Three-way valve applied to a spring return cylinder.
Three-way Valves
Three-way valves are the same as 2-way valves with the addition of a third port for exhausting
downstream air. Three-way valves are available in a normally open or normally closed operating
configurations. These valves are used to control single acting or spring return cylinders and any load
which must be pressurized and alternately exhausted. These valves can also pilot other air operated
valves.
N.O. 3-WAY
SYMBOL
1 IN
2 OUT
3 EX
N.C. 3-WAY
UNACTUATED
1 IN
2 OUT
3 EX
SPRING RETURNED CYL.
IN RETURNED POSTION
N.C. 3-WAY
ACTUATED
1 IN
2 OUT
3 EX
CYLINDER EXTENDED
N.C. 3-WAY
SYMBOL
1 IN
2 OUT
3 EX
