{"product_id":"midline-valve-372u336-inline-spring-loaded-check-valve-lead-free","title":"Midline Valve 372U336 Inline Spring Loaded Check Valve - Lead Free","description":"\u003cp\u003eOur review of the Midline Valve 372U336 looks at whether this inline spring loaded check valve is a practical choice for common plumbing and hydronic tasks. The bottom line: it is best for installers and DIYers who need a compact, threaded check valve with solid mechanical construction and certified lead-free materials. Its single biggest selling point is the heavy duty cast brass body and internal spring design that reliably prevents reverse flow while conforming to NSF\/ANSI-61\/372, making it suitable where lead-free compliance matters.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpring loaded check:\u003c\/strong\u003e The internal spring blocks reverse flow so the valve closes quickly under back pressure and helps prevent unwanted siphoning in piping systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCast brass construction:\u003c\/strong\u003e A heavy duty cast brass body and disc deliver mechanical strength and a stable sealing surface for long service life.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLead free certified:\u003c\/strong\u003e Conforms to NSF\/ANSI-61\/372 so it meets lead-free requirements for potable water and similar use cases.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrosion and dezincification resistant:\u003c\/strong\u003e Material selection reduces risk of dezincification and corrosion in typical water applications, improving reliability.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThreaded FIP connections:\u003c\/strong\u003e 1-1\/4 in FIP threaded ends make the valve easy to install into existing threaded piping without special fittings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure rating:\u003c\/strong\u003e Rated to 200 PSI CWP (non-shock), suitable for many residential and light commercial water systems.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThis check valve is aimed at plumbers, maintenance technicians, and experienced DIYers who need a compact inline solution to prevent backflow or protect equipment such as pumps and tanks. The brass body and certified lead-free construction make it appropriate for potable water lines, irrigation tie-ins, and equipment inlet protection where threaded connections are already used.\u003c\/p\u003e\n\u003cp\u003eThose working with very high transient pressures, specialty fluids, or who require a flanged connection should look elsewhere. Also, buyers seeking fully welded or non-metallic valves for corrosive chemicals will want a product designed specifically for those environments.\u003c\/p\u003e\n\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eRobust cast brass body and disc provide durability and a reliable sealing surface.\u003c\/li\u003e\n\u003cli\u003eThe internal spring design closes quickly to prevent reverse flow and protect downstream equipment.\u003c\/li\u003e\n\u003cli\u003eLead-free certification and ANSI\/CSA approvals make it suitable for potable water applications.\u003c\/li\u003e\n\u003cli\u003eThreaded 1-1\/4 in FIP ends simplify installation into common threaded piping systems.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSome users report mixed results on leakage; proper installation and piping condition are important to avoid leaks.\u003c\/li\u003e\n\u003cli\u003eRated for 200 PSI CWP non-shock; not intended for systems with high water hammer or shock without additional protection.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e372U336\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnection\u003c\/td\u003e\n\u003ctd\u003e1-1\/4 in FIP threaded ends\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBody material\u003c\/td\u003e\n\u003ctd\u003eCast brass, dezincification resistant\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertification\u003c\/td\u003e\n\u003ctd\u003eConforms to NSF\/ANSI-61\/372; CSA approved\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating pressure\u003c\/td\u003e\n\u003ctd\u003e200 PSI CWP (non-shock)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eInline spring loaded check valve for backflow prevention\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Midline Valve 372U336 is a practical, value-minded check valve for potable water and general plumbing where threaded connections are standard. Its heavy duty brass construction and lead-free certification make it a solid pick for installers who need dependable backflow protection, though careful installation is required to avoid the inconsistent leakage some users reported.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eCan this valve be used on potable water lines?\u003c\/strong\u003e\u003cbr\u003eYes. It conforms to NSF\/ANSI-61\/372 and is certified lead free, making it suitable for potable water systems.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat connection size does it use?\u003c\/strong\u003e\u003cbr\u003eThe valve features 1-1\/4 in female iron pipe (FIP) threaded connections for inline installation.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs it suitable for high pressure systems?\u003c\/strong\u003e\u003cbr\u003eIt is rated to 200 PSI CWP non-shock; it is appropriate for many residential and light commercial systems but not for applications with severe water hammer without additional protection.\u003c\/p\u003e","brand":"Midline Valve","offers":[{"title":"Default Title","offer_id":48680459010267,"sku":"B088M38SPX","price":34.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/51BwiuMOSgL._AC_SL1200.jpg?v=1778661985","url":"https:\/\/gearmusthave.com\/products\/midline-valve-372u336-inline-spring-loaded-check-valve-lead-free","provider":"GearMustHave","version":"1.0","type":"link"}