Relays/Valves

・Used when the piping distance between the instrumentation and operational area is long, or when the operational area has a large capacity
・Can help accelerate actuation speed considerably

・The lock-up valve is used when any air source or air supply piping line failure occurs in the air operated process control line.
　Single acting, Double acting: Retains the pressure at the operating area as an emergency operation until the air source recovers to its normal state
　3-port: Changes the supply port if a problem occurs