In a 4/2 valve schematic, which port is typically labeled T?

In a 4/2 valve schematic, which port is typically labeled T?

• A. P
• B. A
• C. B
• D. T

Answer: (D)

Port labeling in pneumatic valves: A 4/2 valve has four ports—P for the pressure supply, two working ports that connect to the actuator, and T for exhaust. The T port is the exhaust path to atmosphere; as the valve shifts, air from one actuator port is vented through T while the other side receives supply air. This arrangement lets the cylinder extend or retract while the opposite side vents to atmosphere, completing the circuit. The P port is the supply, and the two actuator ports (A and B) carry air to the load, not exhaust.

Port labeling in pneumatic valves: A 4/2 valve has four ports—P for the pressure supply, two working ports that connect to the actuator, and T for exhaust. The T port is the exhaust path to atmosphere; as the valve shifts, air from one actuator port is vented through T while the other side receives supply air. This arrangement lets the cylinder extend or retract while the opposite side vents to atmosphere, completing the circuit. The P port is the supply, and the two actuator ports (A and B) carry air to the load, not exhaust.