The Spirax Sarco ABV21i and ABV40i one piece end entry, reduced bore ball valves are fitted with 90 ° rotary spring return pneumatic actuator, for boiler blowdown duties.
They are used in conjunction with a Spirax Sarco blowdown timer to provide timed control of bottom blowdown, ensuring that the recommended boiler blowdown cycles occur with minimum heat loss, avoiding duplication or omission.
The pneumatic actuator, (which can also be operated with other non-corrosive gases), moves through 90 ° to open the valve, and has a spring return fail-close operation.
A switch box is mounted on the actuator, and either or both microswitches may be wired to a Building Management System if required.
Note: The BT1050 blowdown timer uses one switch only to indicate 'valve fully closed' or 'valve not fully closed' positions, and does not indicate that the valve has opened fully.
A solenoid valve is required, which may be directly mounted to the NAMUR (VDI / VDE 3845) interface on the actuator.
A suitable solenoid valve may be selected from the Spirax Sarco MV range. Alternatively, an air supply may be connected directly to the actuator port 'A' ( ¼" BSP), where it is necessary to install the solenoid valve remote from the actuator.
A standard ¼" BSP 3-way solenoid valve may also be used