{"product_id":"bk-521-203bg-malleable-black-iron-coupling-1-2-in","title":"Bk 521-203BG Malleable Black Iron Coupling 1\/2 in","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe BK 521-203BG is a 1\/2 inch malleable black iron pipe coupling designed for joining threaded black iron pipe in gas, compressed air, and general plumbing piping systems. Manufactured to ANSI\/ASTM A-197 material standards with dimensions conforming to ANSI\/ASME B16.3 and threads cut to ANSI B1.20.1, this coupling delivers consistent, code-compliant connections. Each fitting is individually flag tagged and 100% inspected before leaving the factory. Plumbers, pipefitters, and HVAC technicians install this type of coupling when extending or repairing black iron pipe runs.\u003c\/p\u003e\n\u003cp\u003eThis coupling is suited for residential and light commercial applications including natural gas supply lines, propane distribution piping, compressed air systems, and general-purpose black iron piping installations. The 1\/2 inch size is one of the most common sizes found in residential gas branch lines feeding furnaces, boilers, water heaters, and kitchen appliances. It is sold individually and is compatible with standard NPT-threaded pipe of the same nominal size.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eMalleable black iron construction meets ANSI\/ASTM A-197 material specification\u003c\/li\u003e\n  \u003cli\u003eDimensional compliance with ANSI\/ASME B16.3, B16.14, and B16.39\u003c\/li\u003e\n  \u003cli\u003eThreads cut to ANSI B1.20.1 for reliable NPT engagement\u003c\/li\u003e\n  \u003cli\u003e100% inspected and quality tested at the factory\u003c\/li\u003e\n  \u003cli\u003eIndividually flag tagged for easy identification and inventory\u003c\/li\u003e\n  \u003cli\u003eMueller logo cast into body for manufacturer traceability\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style replacement and standard-fit coupling for 1\/2 inch NPT-threaded black iron pipe systems in gas, air, and general plumbing piping applications.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation of black iron pipe fittings on gas lines must be performed by a licensed plumber or gas fitter in accordance with IFGC and local code requirements. Shut off the gas supply and verify zero pressure at the work area before disassembly or installation. Apply an approved pipe thread sealant or PTFE tape rated for gas service to the male threads before assembly. Do not over-tighten; hand-snug plus wrench turns per fitting manufacturer guidance is standard practice, and leak-testing with an approved solution or gas detector is required after completion.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Malleable Black Iron, ANSI\/ASTM A-197\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNominal Pipe Size\u003c\/strong\u003e: 1\/2 inch\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Standard\u003c\/strong\u003e: ANSI B1.20.1 (NPT)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDimensional Standard\u003c\/strong\u003e: ANSI\/ASME B16.3, B16.14, B16.39\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.186 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnit of Measure\u003c\/strong\u003e: Each\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStandard Information\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: BK\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 521-203BG\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"B\u0026K","offers":[{"title":"Default Title","offer_id":51345417470258,"sku":"521-203BG","price":14.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310549871.jpg?v=1782057753","url":"https:\/\/voomisupply.com\/products\/bk-521-203bg-malleable-black-iron-coupling-1-2-in","provider":"Voomi Supply","version":"1.0","type":"link"}