The spool directs move in the pressure port while one other actuator port exhausts to your atmosphere concurrently. These valves control the movement of air visiting the pneumatic actuator. Solenoid valves can be used to pilot the actuator remotely or can be flush mounted directly to the actuator. Base Pad https://josuerbhmr.educationalimpactblog.com/35214200/pressure-gauge-no-further-a-mystery