The ControlAir Type 250 Lockup Air Relay is a reliable unit for fail in place applications of control valves when air supply drops below acceptable pressure levels. Valve or damper position is maintained by capturing air pressure inside the diaphragm chamber (or piston cylinder) of the actuator, when the supply pressure falls below the desired set value. F E A T U R E S • Two Pressure Ranges Available • Manual Relief Valve Allows system bleed down • Corrosion-Resistant Construction • Aluminum or 304 Stainless Steel Material Option • Mounting Bracket Standard for Ease of Installation • No Leakage in Lock-up Position Reliability for fail in place applications

The Type-250 Lock-up Air Relay is designed so that when the supply air pressure falls below a set value (cut-off point) the unit traps the air pressure in the diaphragm chamber of the actuator. The cut-off set point is set to a desired value by compressing the spring adjusting screw. The cut-off set point is adjustable and is generally set at a higher value than required for operation of the control valve. If the control pressure is 3-15 psig (0.2-1.0 BAR), the cut-off set point could be set at 20 psig (1.35 BAR), for example. C U T- O F F S E T T I N G Cut-off set point value has been factory...