{"product_id":"rolacheminjectorcheckvalve521170rol521170","title":"Rola-Chem Injector Check Valve | 521170","description":"\u003cdiv\u003e\n  \u003ch2\u003eRola-Chem 521170 Injection Check Valve – 3\/8\" Hose Barb x 1\/4\" MNPT (PVC) – For Chemical Feed Lines\u003c\/h2\u003e\n\n  \u003cp\u003e\n    The Rola-Chem 521170 is a durable \u003cstrong\u003einjection check valve\u003c\/strong\u003e used on pool\/spa chemical feed systems to help ensure\n    \u003cstrong\u003eone-way flow\u003c\/strong\u003e into the plumbing line. It helps prevent pool water from backing up into the chemical feed tubing and\n    supports more consistent, leak-resistant chemical dosing at the injection point.\n  \u003c\/p\u003e\n\n  \u003ch3\u003eKey Features\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 521170\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Injection check valve (one-way)\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBody Material:\u003c\/strong\u003e PVC\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eInlet Connection:\u003c\/strong\u003e 3\/8\" hose barb (for chemical tubing)\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eOutlet Connection:\u003c\/strong\u003e 1\/4\" MNPT (male NPT) for threading into an injection fitting\/port\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePurpose:\u003c\/strong\u003e Helps prevent backflow and supports reliable chemical feed at the injection point\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eCommon Applications\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eChemical injection point on pool\/spa return plumbing\u003c\/li\u003e\n    \u003cli\u003ePeristaltic metering pump installations using 3\/8\" feed tubing and a 1\/4\" NPT injection port\u003c\/li\u003e\n    \u003cli\u003eReplacing a worn, leaking, or stuck injection\/check valve in an existing dosing setup\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eCompatibility Notes\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eDesigned for systems that use \u003cstrong\u003e3\/8\" chemical tubing\u003c\/strong\u003e on the feed side and a \u003cstrong\u003e1\/4\" NPT threaded\u003c\/strong\u003e injection point.\u003c\/li\u003e\n    \u003cli\u003eIf your tubing size or injection port size is different, choose the correct barb\/NPT combination before ordering.\u003c\/li\u003e\n    \u003cli\u003eInstall at the injection point in the correct flow direction (arrow\/flow marking if present).\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eInstallation Notes\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThreaded connection (1\/4\" MNPT):\u003c\/strong\u003e Use PTFE thread tape or a non-hardening thread sealant compatible with PVC. Tighten snug—do not over-tighten.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTubing connection (3\/8\" barb):\u003c\/strong\u003e Push tubing fully onto the barb. Use a clamp if your application requires it.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eOrientation:\u003c\/strong\u003e Install so chemical flows toward the injection point; reversing it can block flow or allow backflow.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eLocation:\u003c\/strong\u003e Injection points are typically placed downstream of equipment (and after heaters when applicable) following your chemical system’s guidelines.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eSigns It’s Time to Replace\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eChemical line drains backward or loses prime\u003c\/li\u003e\n    \u003cli\u003eWater backs up into the feed tubing or pump line\u003c\/li\u003e\n    \u003cli\u003eVisible leaking at the injection point or around the valve body\u003c\/li\u003e\n    \u003cli\u003eInconsistent chemical delivery even after confirming pump operation\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eRelated Products\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=rola-chem%20injector\"\u003eRola-Chem Injectors \u0026amp; Injection Fittings\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=chemical%20injection%20check%20valve\"\u003eChemical Injection Check Valves\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=3%2F8%20chemical%20tubing\"\u003e3\/8\" Chemical Tubing\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=1%2F4%20npt%20injection%20fitting\"\u003e1\/4\" NPT Injection Fittings\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=ptfe%20thread%20tape\"\u003ePTFE Thread Tape\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=thread%20sealant%20for%20plastic\"\u003eThread Sealant for Plastic Threads\u003c\/a\u003e\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eInstallation \u0026amp; Maintenance Tips\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eFlush\/relieve pressure before removing the valve, and avoid tightening threaded plastic parts under pressure.\u003c\/li\u003e\n    \u003cli\u003eKeep the injection point clean—scale or debris can prevent the check valve from sealing properly.\u003c\/li\u003e\n    \u003cli\u003eIf you service the system seasonally, inspect tubing ends for swelling\/cracking and trim back to fresh tubing before reattaching.\u003c\/li\u003e\n    \u003cli\u003eWhen reinstalling, use only enough thread sealant to seal—excess tape\/sealant can interfere with seating or crack plastic threads if over-tightened.\u003c\/li\u003e\n    \u003cli\u003eAfter startup, verify there is no seepage at the threads and that the feed line holds prime between dosing cycles.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n","brand":"RolaChem","offers":[{"title":"Default Title","offer_id":46797835796655,"sku":"521170","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0734\/6415\/2239\/files\/rola-chem-injector-check-valve-521170-miscellaneous-9150628.jpg?v=1777067952","url":"https:\/\/freshized.com\/products\/rolacheminjectorcheckvalve521170rol521170","provider":"Freshized","version":"1.0","type":"link"}