{"product_id":"mcdonnell-miller-114400-fs4-3-1-flow-switch","title":"McDonnell \u0026 Miller 114400 FS4-3 1\" Flow Switch","description":"\u003cp\u003eProtect your critical heating and cooling systems from potential dry-fire or flow-related damage with the \u003cb\u003eMcDonnell \u0026amp; Miller 114400 FS4-3\u003c\/b\u003e 1\" flow switch. This robust device is engineered to monitor liquid flow in pipes and actuate electrical circuits, ensuring your equipment operates only under safe, optimal flow conditions.\u003c\/p\u003e\u003cp\u003eThe unit functions by utilizing a paddle-actuated mechanism that detects the presence or absence of flow within the line. When the liquid moves the paddle, it triggers a precision-built internal switch, providing instantaneous status feedback to your system's control board or alarm circuitry.\u003c\/p\u003e\u003ch4\u003eKey System Performance Baselines:\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eReliable Sensing:\u003c\/b\u003e Precision mechanical switch design ensures consistent, accurate flow detection.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eHigh Durability:\u003c\/b\u003e Built to withstand demanding hydronic environments with professional-grade materials.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eStandardized Connection:\u003c\/b\u003e Features a 1\" NPT connection for seamless integration into common pipe sizes.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e⚠️ \u003cstrong\u003eApplication Profile:\u003c\/strong\u003e Primarily used in commercial and residential HVAC systems, chilled water loops, and boiler auxiliary monitoring to prevent pump damage and safeguard heat exchangers from overheating due to stagnant flow.\u003c\/p\u003e","brand":"McDonnell \u0026 Miller","offers":[{"title":"Default Title","offer_id":43123964739678,"sku":"114400","price":788.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0663\/7151\/8558\/files\/114400_image_bf961516-7138-46b3-96d3-1d671d6061a8.png?v=1786027145","url":"https:\/\/nationalboilersupply.com\/products\/mcdonnell-miller-114400-fs4-3-1-flow-switch","provider":"National Boiler Supply","version":"1.0","type":"link"}