{"product_id":"lisnhlin-brass-rv-vacuum-breaker-check-valve-1-2-npt-male-upgraded-8-125-psi-replacement-for-b-b-model-571","title":"Lisnhlin Brass RV Vacuum Breaker Check Valve 1\/2\" NPT Male — Upgraded 8–125 PSI Replacement for b\u0026b Model 571","description":"\u003cp\u003e\u003cstrong\u003eLisnhlin's 571-VAC-CHK-A is an upgraded brass vacuum breaker check valve designed to replace leaking b\u0026amp;b Model 571 units and protect your RV's freshwater from backflow.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf your camper's black tank flushing line is allowing waste or wastewater to siphon back toward the freshwater source, this brass check valve provides a durable, straightforward fix. Built to fit between the freshwater inlet and the tank flusher, the 571-VAC-CHK-A is a direct service replacement engineered for long-term reliability during road travel and campground use.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this valve stop backflow into my freshwater system?\u003c\/h3\u003e\n\u003cp\u003eThe valve functions as a one-way vacuum breaker and check valve, mechanically preventing water from flowing backwards into the freshwater line. When pressure drops or a siphon effect occurs, the internal check closes to block contaminated water from re-entering your potable supply.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOne-way flow design prevents reverse flow and back-siphonage.\u003c\/li\u003e\n  \u003cli\u003eInstalled between freshwater inlet and black tank flusher for isolation.\u003c\/li\u003e\n  \u003cli\u003eReduces risk of cross-contamination during flushing operations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the material and pressure specifications?\u003c\/h3\u003e\n\u003cp\u003eThis upgraded unit uses brass construction to resist corrosion and handle typical RV water pressures safely. The valve is rated for 8–125 PSI, making it suitable for most RV potable water systems and campground hookups.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSolid brass body for improved durability over plastic alternatives.\u003c\/li\u003e\n  \u003cli\u003ePressure capacity: 8–125 PSI to cover common RV water scenarios.\u003c\/li\u003e\n  \u003cli\u003eDesigned for repeated use without performance degradation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eIs installation complicated and what fittings are required?\u003c\/h3\u003e\n\u003cp\u003eInstallation is straightforward: both ends come with 1\/2\" NPT male threads that fit standard RV plumbing adapters and lines. Positioning matters — the valve must be mounted at least 6 inches above the highest point of any device connected to the waste tank flusher to operate correctly.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e1\/2\" NPT male threads on inlet and outlet for simple plumbing connections.\u003c\/li\u003e\n  \u003cli\u003eMount at minimum 6 inches above highest connected point to prevent siphoning.\u003c\/li\u003e\n  \u003cli\u003eNo special tools required for most installations beyond common pipe wrenches and thread sealant.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this part fit my RV or camper model?\u003c\/h3\u003e\n\u003cp\u003eThe 571-VAC-CHK-A is designed as a replacement for b\u0026amp;b Model 571 vacuum breaker check valves and works with many RVs, travel trailers, and motorhomes that use the same black tank flush arrangement. Always confirm thread size and clearance before purchase to ensure compatibility.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect replacement for b\u0026amp;b Model 571 check valve assemblies.\u003c\/li\u003e\n  \u003cli\u003eCompatible with most black tank flush systems that use 1\/2\" NPT connections.\u003c\/li\u003e\n  \u003cli\u003eWorks across a broad range of RVs, campers, and trailers as a standard fix for leaks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The Lisnhlin 571-VAC-CHK-A is aimed at RV owners, repair technicians, and DIY campers who need a reliable replacement for a cracked or leaking vacuum breaker in their black tank flushing system. It suits anyone seeking a durable brass alternative to plastic valves, a straightforward field-service part for preventing backflow, or a preventative upgrade to protect potable water during tank maintenance.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use this check valve on any RV black tank flush system?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes if your system uses 1\/2\" NPT fittings and the b\u0026amp;b Model 571 form factor; confirm thread type and clearance before installing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Do I need special tools to install the Lisnhlin 571-VAC-CHK-A?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No special tools are required—common wrenches and thread sealant are typically sufficient for a secure installation.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Lisnhlin","offers":[{"title":"Default Title","offer_id":48082962841758,"sku":"B0D4Z8RDRG","price":52.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/lisnhlin-front-view-brass-valve.jpg?v=1785820616","url":"https:\/\/northtrailauto.ca\/products\/lisnhlin-brass-rv-vacuum-breaker-check-valve-1-2-npt-male-upgraded-8-125-psi-replacement-for-b-b-model-571","provider":"North Trail Auto","version":"1.0","type":"link"}