On-off or shut off valves are a necessary safety component of every pneumatic system. They can be used to exhaust downstream pressure when carrying out maintenance or as a convenient way to isolate supplied pressure. Soft start valves can be used to minimise system shock on start-up, by setting the initial rate of inflow and system pressurisation. A soft start valve will also exhaust the system quickly to allow safe servicing.
Many on-off and soft start valves are supplied as modules that can conveniently be connected with other components in an FRL assembly. Electric units will integrate easily with machine controls, while manual units may be used to isolate power by locking them in the exhaust position. Simple on-off valves can be of the quarter turn ball variety, venting downstream pressure through an exhaust port when the handle is turned to turn off inlet pressure. Space-saving three-port valves with a modular connection can also provide residual pressure relief in a pneumatic system, as well as downstream exhaust for maintenance purposes.
Soft start valves enable the initial pressurisation of a pneumatic system to be effected gradually, while still allowing for quick downstream exhaust. The direction of air flow can be changed and easily identified by the orientation of operational handles and/or labels. Soft start valves offer improved airflow and energy efficiency, and can be used as self-contained units or as part of an FRL assembly with modular spacers. Some options also include a lock-out capability for safer servicing.