{"product_id":"mcdonnell-miller-120611-fs251-general-purpose-flow-switch-with-nema-1-enclosure","title":"McDonnell \u0026 Miller 120611 FS251 General Purpose Flow Switch with NEMA 1 Enclosure","description":"\u003cp\u003eReliable flow detection is essential for protecting hydronic equipment from damage due to insufficient flow rates, and the \u003cstrong\u003e120611\u003c\/strong\u003e McDonnell \u0026amp; Miller \u003cstrong\u003eFS251\u003c\/strong\u003e provides the precision required for these critical systems. Designed for general-purpose applications, this flow switch serves as a dependable control mechanism to monitor the presence or absence of liquid flow in pipelines, ensuring that pumps and burners operate only under safe conditions.\u003c\/p\u003e\u003cp\u003eThe unit functions by utilizing a paddle-actuated mechanism inserted directly into the fluid stream. As flow moves the paddle, it mechanically activates a precision snap-acting switch, providing either a make or break contact based on your system's specific requirements. This direct mechanical response provides an immediate signal, making it ideal for maintaining consistent performance across various industrial and commercial installations.\u003c\/p\u003e\u003ch4\u003eKey System Performance Baselines:\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurable Construction:\u003c\/strong\u003e Built to withstand rigorous operational demands while maintaining long-term sensitivity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety Enclosure:\u003c\/strong\u003e Features a robust NEMA 1 rated housing for protection against accidental contact.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecise Switching:\u003c\/strong\u003e Engineered for consistent, repeatable activation across a wide range of flow velocities.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e⚠️ \u003cstrong\u003eApplication Profile:\u003c\/strong\u003e Ideal for monitoring liquid flow in HVAC water systems, hydronic heating loops, water treatment facilities, and process cooling lines where reliable pump protection is mandatory.\u003c\/p\u003e","brand":"McDonnell \u0026 Miller","offers":[{"title":"Default Title","offer_id":43124295303262,"sku":"120611","price":224.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0663\/7151\/8558\/files\/120611_image_3e66f5bc-ffb7-451b-bda9-1f88e14f4ddd.png?v=1786034754","url":"https:\/\/nationalboilersupply.com\/products\/mcdonnell-miller-120611-fs251-general-purpose-flow-switch-with-nema-1-enclosure","provider":"National Boiler Supply","version":"1.0","type":"link"}