ITT McDonnell & Miller has introduced a series of environmentally friendly Low Water Cut-Off/Pump Controllers featuring mercury-free snap-action switches. The new Series 150S and 157S are safer for the environment and more convenient for installers since mercury-free switches require no special handling or disposal. And with the escalating price of mercury, the Series 150S and 157S are also more economical.

Other key features of the Series 150S and 157S include:

• Head-to-body seal interface with a raised flange for a more positive seal and a full bolt pattern gasket that's easier to install
   
•  Maximum differential (MD) models are available to prevent nuisance burner shutdown in lower pressure applications
   
•  Fully enclosed junction box which protects the control from dust and dirt but allows easy wiring
   
•  A Monel bellows to provide corrosion resistance
   
•  An integral water column (Model 157S), which eliminates the need for a separate water column, as required for all steam boilers

Designed for a maximum pressure of up to 150 psi (10.5 kg/cm2), applications for the new Series 150S and 157S include primary or secondary pump controller/low water fuel cut-offs for commercial and industrial steam boilers; and motorized valve controllers. Low water cut offs, high water cut-offs, and alarm actuators for vessels and tanks.

Replacement head mechanisms are available and are completely interchangeable with the popular Series 150 and 157 controls already installed in the field. Although the mercury switch units continue to be available, ITT McDonnell & Miller strongly encourages installers to switch to more environmentally friendly and economical mercury free units.