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 trades applications.
General Purpose Liquid Flow Switch, Series FS250
General-Purpose, Liquid Flow Switches, the Series FS250 – FS251 (NEMA1 version), and FS254 (NEMA4 version). These flow switches incorporate key changes to address customer expressed needs of greater reliability and lower flow sensing capabilities in a general purpose flow switch.
Model FS1-W High Sensitivity Liquid Flow Switches
High sensitivity liquid flow switch. For applications requiring a water-tight, dust-tight, or a NEMA 4X rated flow switch
Model FS6-W High Sensitivity Liquid Flow Switches
High sensitivity liquid flow switch. For applications requiring a water-tight, dust-tight, or a NEMA 4X rated flow switch
RS-1-HP Series-RS High Pressure Remote Sensor
For single sensor applications with high-pressure environments. Requires additional probe rod.
RS-1-LP Low Pressure
For single sensor applications with high-pressure environments. Can be installed in horizontal orientation
Series 101-A Electric Water Feeders
For use on low pressure boilers with cold water feed. The Series 101-A can be used with mechanical or electronic low water cut-off controls.
Series 150S/157S Low Water Cut Off/Pump Controller
For commercial and industrial low or high pressure boiler applications. For boilers of any steaming capacity. Snap action switches for high temperature service. Cut-off and alarm actuation. Maximum differential operation - Prevents nuisance burner shutdowns in low pressure applications.
Series 21/221 Make-Up Water Feeders
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. Maximum water supply pressure 150 psi.
Series 25-A Make-Up Water Feeder
For boiler receiver tanks. Float operated. Proportional feed action. Soft seat provides positive seal. Seal between float chamber and valve chamber is not a positive seal.
Series 27-W Valve
For commercial and industrial liquid level open tank applications. Maximum pressure 35 psi. Maximum supply pressure 100 psi. Minimum liquid temperature 40°F. Maximum liquid temperature 212°F.
Series 42S Low Water Cut-Off/Pump Controllers
For residential, commercial, and industrial low and medium pressure steam boilers with a separate water column. For boilers of any steaming capacity. Monel bellows provides corrosion resistance.
Series 47-2/247-2 Mechanical Water Feeder/LWCO
For steam and hot water boilers with cold water feed. Continuous maintenance of minimum safe water level, independent of electrical service. Proportional feed action. Quick hook-up fittings provided. Quick-change replaceable cartridge valve and strainer. Model 47 can be field upgraded with a No. 2 switch to add low water cut-off function.
Series 47/247 Water Feeders
For steam and hot water boilers with cold water feed. Continuous maintenance of minimum safe water level, independent of electrical service. Proportional feed action. Quick-change replaceable cartridge valve and strainer. Isolated feed valve minimizes lime and scale build-up.
Series 51-S/51-S-2 Mechanical Water Feeders/Low Water Cut-Offs
For high capacity [up to 35,000 sq. ft. (3250m2)] low pressure steam and hot water boilers with cold water feed. Maximum water supply pressure 100 psi. Maximum inlet water temperature 120°F. Maximum vessel pressure 35 psi.