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McDonnell & Miller General Catalogue Industrial Controls

McDonnell & Miller Series 157S Low Water Cut-Offs Mechanical For Steam Boilers

For residential, commercial and industrial low or high pressure boiler applications
• For boilers of any steaming capacity
• Monel bellows provides corrosion resistance
• Float chamber with integral water column provided
•`Snap action 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
– Integral conductance probes for additional levels and greater operating differential-Model 157S-RBP-MD
– 1″ or 11⁄4″ NPT equalizing tappings
– 1⁄2″ or 3⁄4″ NPT tappings for gauge glass/tri-cock installations
– BSPT threads
• Maximum pressure 150 psi (10.5 kg/cm2)

Model 157S-MD

Maximum differential operation
– Prevents nuisance burner shutdowns in low pressure applications operating less than 50 psi (3.5 kg/cm2)
• For additional information see PDF

The McDonnell & Miller Series 157S provides continuous protection against a low water condition. Furthermore it satisfies pump control needs for commercial and industrial steam boilers.

If you need a different model other than those listed, please contact us at

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