{"product_id":"john-guest-12mm-check-valve","title":"John Guest 12mm Check Valve","description":"\u003cp\u003eThe \u003cstrong\u003eJohn Guest 12mm Check Valve\u003c\/strong\u003e is a push-fit non-return valve designed to prevent backflow in campervan, motorhome and caravan water systems. Installed in-line within your 12mm pipework, it ensures water flows in one direction only — protecting pumps, heaters and appliances from reverse flow and pressure issues.\u003c\/p\u003e\u003cp\u003eUsing trusted \u003cstrong\u003eJohn Guest Speedfit technology\u003c\/strong\u003e, this valve connects quickly and securely without tools, clamps or sealants. Simply push your 12mm pipe into each end for a reliable, leak-tight installation.\u003c\/p\u003e\u003cp\u003eIdeal for fresh water systems, the check valve helps maintain consistent water pressure, prevents back siphoning, and improves overall plumbing reliability in mobile and off-grid environments.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e12mm push-fit non-return (check) valve\n\u003c\/li\u003e\n\u003cli\u003ePrevents backflow in water systems\n\u003c\/li\u003e\n\u003cli\u003eTool-free Speedfit installation\n\u003c\/li\u003e\n\u003cli\u003eSuitable for hot and cold potable water\n\u003c\/li\u003e\n\u003cli\u003eProtects pumps, heaters and appliances\n\u003c\/li\u003e\n\u003cli\u003eIdeal for campervan, caravan \u0026amp; motorhome plumbing\n\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eTypical Uses\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eInstalled after water pumps\n\u003c\/li\u003e\n\u003cli\u003ePreventing backflow from accumulators\n\u003c\/li\u003e\n\u003cli\u003eProtecting water heaters\n\u003c\/li\u003e\n\u003cli\u003eMaintaining one-way flow in fresh water systems\n\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eA simple but essential component for building a safe and professional campervan plumbing system.\u003c\/p\u003e","brand":"Nomadic Leisure","offers":[{"title":"Single","offer_id":56864774914421,"sku":"12SCV","price":6.75,"currency_code":"GBP","in_stock":true},{"title":"10 Pack","offer_id":56864774947189,"sku":"12SCV-10","price":81.48,"currency_code":"GBP","in_stock":true},{"title":"100 Pack","offer_id":56864774979957,"sku":"12SCV-100","price":726.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0916\/7182\/2709\/files\/Screenshot2026-03-03144231.png?v=1772548961","url":"https:\/\/nomadicleisure.co.uk\/products\/john-guest-12mm-check-valve","provider":"Nomadic Leisure","version":"1.0","type":"link"}