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McDonnell and Miller MM 114400 is a flow switch, model FS4-3, designed for water level control and flow sensing in boiler and water system applications. The device operates as a flow-responsive switch to monitor liquid flow and provide a switching input to control systems in heating and water management installations. Relevant search terms include flow switch FS4-3, MM-114400, boiler flow sensor, and water system flow control.
Flow switch FS4-3 (MM 114400) for water level control and boiler or water system flow sensing
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