The EL-O-Matic Block and Vent Valve allows pneumatic isolation of actuator from the control system for service purposes. It is suitable for double acting or spring return actuators and can be used on applications where “On site“ servicing of the actuator is required and where the actuator needs to be pneumatically isolated from the control system. The valve block is fixed directly onto the actuator's NAMUR air entry manifold and has a further NAMUR interface so that a suitable solenoid valve may be directly mounted.