{"product_id":"mcdonnell-miller-171702-150s-hi-pressure-level-control","title":"McDonnell \u0026 Miller 171702 150S High Pressure Low Water Cut-Off \u0026 Boiler Pump Controller (1 Inch NPT, 150 PSI)","description":"\u003ch2\u003eMcDonnell \u0026amp; Miller 171702 (Model 150S) Combination Low Water Cut-Off \u0026amp; Pump Controller\u003c\/h2\u003e\n\u003cp\u003e\n  Designed for primary or secondary low water fuel cut-off and automatic feed pump regulation on commercial and industrial steam boilers, the \n  \u003cstrong\u003eMcDonnell \u0026amp; Miller 171702 (Model 150S)\u003c\/strong\u003e is the industry-standard mechanical level controller for high-pressure steam applications. Operating at maximum steam pressures up to 150 PSI (10.5 kg\/cm²), this heavy-duty control features a rugged cast iron float chamber and corrosion-resistant Monel bellows seal isolation.\n\u003c\/p\u003e\n\u003cp\u003e\n  Unlike maximum-differential variants, the standard \u003cstrong\u003e150S\u003c\/strong\u003e features factory-calibrated standard switching levels to provide tight, responsive water line control. Its internal mechanism incorporates two heavy-duty snap action switches—a single pole, single throw (SPST) switch for direct boiler feed pump activation and a single pole, double throw (SPDT) switch for low water burner cut-off and alarm circuit operation.\n\u003c\/p\u003e\n\n\u003ch4\u003eKey Performance \u0026amp; Engineering Highlights:\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n    \u003cstrong\u003eStandard Switching Differential:\u003c\/strong\u003e Provides tight water line maintenance and rapid low-water burner shutdown protection.\n  \u003c\/li\u003e\n  \u003cli\u003e\n    \u003cstrong\u003eSealed Monel Bellows Isolation:\u003c\/strong\u003e Prevents steam, condensate, and boiler water contaminants from entering the switch housing, extending mechanical life.\n  \u003c\/li\u003e\n  \u003cli\u003e\n    \u003cstrong\u003eDual Snap Switches:\u003c\/strong\u003e Contains 1 SPST snap switch for feed pump control and 1 SPDT snap switch for low water fuel cut-off (LWCO) and alarm activation.\n  \u003c\/li\u003e\n  \u003cli\u003e\n    \u003cstrong\u003e1\" NPT Female Tappings:\u003c\/strong\u003e Standard 1\" female NPT side equalizing connections simplify rigid pipe mounting directly to the boiler shell or external water column.\n  \u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\n  ⚠️ \u003cstrong\u003eApplication Profile:\u003c\/strong\u003e Essential for commercial and industrial steam boilers of any steaming capacity requiring primary\/secondary low water fuel cut-off, automated boiler feed pump control, or high\/low level alarm signaling up to 150 PSI.\n\u003c\/p\u003e","brand":"McDonnell \u0026 Miller","offers":[{"title":"Default Title","offer_id":43041399865438,"sku":"MM-171702","price":1595.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0663\/7151\/8558\/files\/McDonnell_and_Miller_171802_150S-MD_Low_Water_Cut-Off_and_Boiler_Pump_Controller_1_Inch_NPT_150_PSI.jpg?v=1784749864","url":"https:\/\/nationalboilersupply.com\/products\/mcdonnell-miller-171702-150s-hi-pressure-level-control","provider":"National Boiler Supply","version":"1.0","type":"link"}