McDonnell & Miller 93-7B-HD Pump Controller

The McDonnell & Miller 93-7B-HD (Part Number 163200) is a high-performance head mechanism only designed for direct replacement in Series 93 and 193 boiler water level controls. This heavy-duty unit integrates a low water cut-off and pump controller, specifically engineered for industrial and commercial steam boilers. Featuring a No. 7B potentiometer switch, it provides a 135-ohm proportional signal for modulating feed water valves, ensuring precise water level maintenance in systems up to 150 PSI. Built with a magnetic repulsion design, it eliminates common failure points like bellows, making it a reliable choice for veterans managing high-pressure steam environments. Using this replacement head mechanism allows for a rapid "bolt-on" installation, as it utilizes the existing float chamber, minimizing downtime and avoiding the need to break into the main piping. It is an essential component for any technician maintaining boiler water level controls that require consistent, proportional feedback for optimized burner performance.

• Precise Level Control: The integrated 7B switch provides 135-ohm proportional resistance to accurately modulate motorized feed valves.
• Simplified Service: Designed as a head mechanism only, allowing field technicians to replace the internal components without disturbing the steam piping or float bowl.
• Enhanced Reliability: Utilizes magnetic repulsion to actuate switches, removing the mechanical stress associated with traditional bellows.
• High Pressure Compatibility: Rated for a maximum steam pressure of 150 PSI, ideal for heavy-duty commercial boiler applications.
• Universal Series Fit: Direct replacement for all Series 93 and Series 193 boiler control assemblies.

Does this include the float chamber?
No, the 93-7B-HD is the head mechanism only. It includes the internal assembly, head flange, and the 7B switch, but you must install it onto your existing Series 93 float bowl.

What type of valve signal does the 7B switch output?
It provides a 135-ohm potentiometer signal intended for proportional control, typically used with modulating electric valve actuators to maintain a constant water level rather than a simple on/off operation.

Can I use this for a manual reset application?
This model (163200) features the standard 7B switch. If your system requires a manual reset for the burner circuit, please confirm your specifications as manual reset models typically use the 7B-M switch configurations.

This item is not eligible for free shipping.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.