{"product_id":"metal-fab-3m12-double-wall-b-vent-pipe-3x12-in-twist-lock","title":"Metal-fab 3M12 Double Wall B-vent Pipe 3x12 in Twist Lock","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe METAL-FAB 3M12 is a double-wall, round Type B gas vent pipe section designed for venting natural gas and propane appliances in residential and light-commercial applications. The inner wall is 0.012-inch aluminum alloy and the outer wall is 0.018-inch G90 galvanized steel, with an integral annular insulating air space between the two walls. This construction maintains flue gas temperature and reduces condensation risk. The section measures 3 inches in diameter and 12 inches in length and connects using a positive twist-lock end design that requires no additional adapters or field measuring. Licensed gas technicians and HVAC service professionals install this pipe as part of a listed B-vent system.\u003c\/p\u003e\u003cp\u003eThe 3M12 is suited for residential gas furnaces, boilers, water heaters, and similar Category I appliances that require a Type B vent. The twist-lock male and female ends come factory assembled, making the section ready to install directly from the box. This eliminates the custom cutting and adapter work common with rigid straight-pipe sections, reducing labor time when connecting appliances to an existing rigid B-vent system. It functions as a universal connector between appliance collars and rigid B-vent pipe runs where a short, flexible-length section is needed.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eDouble-wall construction with 0.012-inch aluminum alloy inner wall and 0.018-inch G90 galvanized steel outer wall\u003c\/li\u003e\n\u003cli\u003eIntegral annular insulating air space maintains flue gas temperature and limits heat transfer to surrounding structure\u003c\/li\u003e\n\u003cli\u003ePositive twist-lock ends are factory assembled — no field cutting, special adapters, or measuring required\u003c\/li\u003e\n\u003cli\u003eRated to 530 degrees F for safe use in standard Category I venting applications\u003c\/li\u003e\n\u003cli\u003eMeets UL 441 and NFPA 54\/211 standards for Type B gas vent systems\u003c\/li\u003e\n\u003cli\u003eMade in USA\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement and standard section for residential and light-commercial Type B gas vent systems using 3-inch diameter B-vent pipe with twist-lock connections.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation must be performed by a qualified gas technician or licensed HVAC professional in accordance with NFPA 54, NFPA 211, and applicable local codes. Shut off gas supply and allow the venting system to cool completely before servicing or replacing any vent section. Maintain required clearances to combustibles as specified by the vent system manufacturer and local code. Do not mix vent pipe brands or connection types within the same listed vent system without confirming cross-brand compatibility with the manufacturer.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePipe Diameter\u003c\/strong\u003e: 3 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLength\u003c\/strong\u003e: 12 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWall Type\u003c\/strong\u003e: Double Wall, Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnd Type\u003c\/strong\u003e: Twist Lock\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInner Wall Material\u003c\/strong\u003e: Aluminum Alloy\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Wall Material\u003c\/strong\u003e: G90 Galvanized Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInner Wall Thickness\u003c\/strong\u003e: 0.012 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Wall Thickness\u003c\/strong\u003e: 0.018 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature Rating\u003c\/strong\u003e: 530 degrees F\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplicable Standards\u003c\/strong\u003e: UL 441, NFPA 54\/211\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin\u003c\/strong\u003e: USA\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: METAL-FAB\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 3M12\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"METAL-FAB","offers":[{"title":"Default Title","offer_id":51284055818546,"sku":"3M12","price":19.11,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/309277701.jpg?v=1781067338","url":"https:\/\/voomisupply.com\/products\/metal-fab-3m12-double-wall-b-vent-pipe-3x12-in-twist-lock","provider":"Voomi Supply","version":"1.0","type":"link"}