McDonnell Miller Controls

Additional Information
McDonnell & Miller low water cut-offs provide a reliable method of controlling a boiler feed pump. They are mounted at the boiler water line and starts and stops the pump as the boiler water dictates. Consequently, it holds the boiler water level at the limits recommended by the boiler manufacturer to maintain maximum steaming efficiency. McDonnell & Miller low water cut-offs are available in float-operated or probe and float built-in styles.
McDonnell & Miller is a leader in engineering and manufacturing boiler controls, liquid level controls, low-water cutoffs, and flow switches for steam and hot water boilers in industrial, commercial and building trade applications.
Low Water Cut Off
Series 61, 63, 64, 764, 67, 69, 150, 157,
764, 767, 42, 93, 94, 193, 194
Features and Benefits:
For commercial and industrial low or high pressure boiler applications
For boilers of any steaming capacity
Monel bellows provides corrosion resistance
Snap action switches for high temperature service
1 Single pole, single throw switch for pump control
1 Single pole, double throw switch for low water
Cut-off and alarm actuation
Optional Features

Manual reset
2 Single pole, single throw switches
2 Single pole, double throw switches
Float block
BSPT threads
Maximum pressure 150 psi (10.5 kg/cm2)
Model 150S-MD Maximum differential operation – Prevents nuisance burner shutdowns in low pressure applications.

For boiler receiver tanks
Direct mounting eliminates need for equalizing connections
Proportional feed action
Mounting Flange – six 7⁄16″ (11.1mm) bolt holes on a 53⁄4″ (146mm) bolt circle
Soft seat provides positive seal
Maximum water supply pressure 150 psi (10.5 kg/cm2)
Maximum inlet water temperature 120°F (49°C)
Maximum vessel pressure 35 psi (2.5 kg/cm2)

Primary low water fuel cut-off protection and pump control for commercial and industrial steam boilers
Motorized valve controller, low water cut-off, high water cut-off and alarm actuator for boilers, vessels and tanks