{"product_id":"a-y-mcdonald-5421-325-pressure-relief-valve-0-5-in-mpt","title":"A.y. Mcdonald 5421-325 Pressure Relief Valve 0.5 in Mpt","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe A.Y. MCDONALD 5421-325 is a lead-free pressure relief valve designed for residential and light commercial plumbing systems. Threaded with a 0.5-inch male pipe thread (MPT) connection, it provides automatic pressure relief at a 75 psi set point, protecting water lines, water heaters, and closed-loop systems from over-pressurization. The lead-free construction meets current federal and state potable water compliance standards. Licensed plumbers install this valve as a primary or supplemental safety device on water supply systems where pressure regulation and code-mandated relief protection are required.\u003c\/p\u003e\n\u003cp\u003eThis relief valve is suited for residential water heating systems, potable water supply lines, and light commercial plumbing applications where a compact 0.5-inch MPT connection is appropriate. It is typically installed on water heaters, expansion tanks, boilers, or inline on supply runs requiring pressure protection. The lead-free rating makes it acceptable for use on systems carrying drinking water under applicable plumbing codes.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eLead-free construction compliant with potable water standards\u003c\/li\u003e\n  \u003cli\u003e0.5-inch MPT connection for standard threaded pipe installation\u003c\/li\u003e\n  \u003cli\u003e75 psi factory-set relief pressure\u003c\/li\u003e\n  \u003cli\u003eCompact design suitable for water heaters and supply line applications\u003c\/li\u003e\n  \u003cli\u003eAutomatic pressure relief helps protect plumbing systems from over-pressurization\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style replacement or new-installation pressure relief valve for residential and light commercial plumbing systems requiring a 0.5-inch MPT lead-free relief valve rated at 75 psi.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eA licensed plumber should install or replace pressure relief valves in accordance with local plumbing codes and the International Plumbing Code (IPC). Shut off the water supply and relieve system pressure before removing or installing this valve. Use thread sealant tape rated for potable water on all threaded connections. Never cap or plug the discharge port of a relief valve once installed.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConnection Type\u003c\/strong\u003e: 0.5 inch MPT\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRelief Pressure\u003c\/strong\u003e: 75 psi\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLead Free\u003c\/strong\u003e: Yes\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: A.Y. MCDONALD\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 5421-325\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"AY MCDONALD","offers":[{"title":"Default Title","offer_id":51234073313586,"sku":"5421-325","price":28.42,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/307628793.jpg?v=1780116911","url":"https:\/\/voomisupply.com\/products\/a-y-mcdonald-5421-325-pressure-relief-valve-0-5-in-mpt","provider":"Voomi Supply","version":"1.0","type":"link"}