1/2" 9D-M3 Backflow Preventer – Brass Dual Check Valve with Intermediate Atmospheric Vent for Boiler Feed & Water Supply Protection, Female Union Inlet & Outlet, Vertical or Horizontal Installation

Protect your water system with the 1/2" 9D-M3 Backflow Preventer, a high-quality dual check valve designed for both residential and commercial use. Built from durable brass with stainless steel internal components and a robust rubber disc, this valve delivers reliable, leak-free performance for years, even under fluctuating pressure and extreme temperatures.Ideal for boiler feed lines, laboratory equipment, sterilizers, process tanks, and dairy systems, it ensures return pressure never drops below system pressure, preventing contamination and safeguarding your water supply. The universal 1/2-inch female NPT connections make installation seamless, and the valve can be mounted vertically or horizontally to suit any setup.Engineered for continuous operation, it handles hot or cold water within a temperature range of 33°F to 210°F and pressures up to 175 PSI, with a minimum operating pressure of 25 PSI. Precision-machined double check mechanism guarantees consistent performance and tight sealing, even during frequent pressure surges.User-friendly features include cast-in “INLET” & “VENT” labels for correct orientation and clear installation guidance. For safety, a drain pipe should be installed approximately 12 inches above the floor drain, and exhaust ports must remain unobstructed. When used with boilers, avoid air gap fittings on surfaces to prevent scalding.This backflow preventer combines durability, safety, and versatility, giving you peace of mind and reliable water protection. Backed by responsive customer support, installation and troubleshooting are simple and hassle-free.

• 1️⃣ Standard Size & Wide Compatibility: Universal 1/2-inch female NPT connections fit standard U.S. piping. Ideal for boiler feed lines, laboratory equipment, sterilizers, process tanks, dairy systems, and other small supply lines
• 2️⃣Reliable Performance Under Pressure: Dual check valve designed for hot or cold water. Operates continuously at temperatures from 33°F to 210°F and up to 175 PSI (tested to 5000+ cycles). Minimum operating pressure: 25 PSI. Fail-safe reliability in extreme conditions
• 3️⃣ Premium Materials: The 1/2" 9D-M3 Backflow preventer construction consists of brass body, stainless steel working parts, integral filter and durable rubber disc. The inlet and outlet of the inner connector are connected. Main check valve with rubber disc seat combined with matching rubber parts to ensure tight closing
• 4️⃣ Safe & User-Friendly Design: Cast-in “INLET” & “VENT” labels ensure correct installation. Can be mounted vertically or horizontally. Requires drain pipe installed ~12 inches above floor drain to prevent water damage. Do not block exhaust ports; avoid air gap fittings on boilers to prevent scalding
• 5️⃣ Reliable Support & Satisfaction: Dedicated customer support ready to assist with installation or troubleshooting. We strive for your complete satisfaction and provide fast, professional service whenever needed