Amtrol 446 Air Purger 125 Psi Cast Iron for 700 Series Automatic Air Vents and Extrol Expansion Tanks

Product Description

The Amtrol 446 Air Purger is a cast iron air separation device built for hot water heating systems. It continuously separates dissolved and entrained air from circulating system water and routes that air to an automatic air vent for hands-free removal. This eliminates the need for frequent manual venting and keeps the heating system running efficiently. The 446 is designed for use with Amtrol 700 Series Automatic Air Vents and Extrol Expansion Tanks, making it a natural fit for complete Amtrol hydronic system assemblies. It is rated for 125 psi working pressure and is constructed from durable cast iron for long service life in commercial and residential hydronic heating applications. HVAC technicians and plumbing professionals rely on air purgers like the Amtrol 446 to solve one of the most common problems in closed-loop hot water heating systems: air entrainment. Water used to initially fill a hydronic system carries dissolved air. Make-up water added over time also introduces air into the loop. When that water is heated, the dissolved air is released and allowed to circulate through the piping. This causes noise, reduces heat transfer efficiency, and can lead to airlocks that block flow in radiators, baseboard heaters, and fan coil units. The Amtrol 446 Air Purger addresses this problem at the source by providing a dedicated collection and separation point in the system piping. It features a 2 inch system connection that sets the point of no pressure change in the hydronic loop. The top connection is 1/2 inch NPT, and an additional 1/2 inch NPT tapping is also provided for flexible installation. The unit measures 8 inches in length, 3.5 inches in width, and 5 inches in height. It is compliant with low lead IAPMO requirements, meeting current standards for potable and heating system installations. This purger is a dependable component for any hydronic heating setup requiring reliable automatic air elimination.

• Continuously separates and collects air from circulating hot water heating system fluid for automatic venting
• Compatible with Amtrol 700 Series Automatic Air Vents and Extrol Expansion Tanks for integrated hydronic system builds
• Cast iron construction rated to 125 psi with low lead IAPMO compliance and flexible 1/2 inch NPT connections

Product Highlights

The Amtrol 446 Air Purger provides reliable, automatic air separation in closed-loop hot water heating systems. Its cast iron body, 125 psi rating, and standard NPT connections make it a practical choice for HVAC and plumbing professionals installing or servicing hydronic heating equipment.

Product Information

Standard Information

• Brand: AMTROL
• Manufacturer Part Number: 446

Technical Specifications

• Material: Cast Iron
• Maximum Working Pressure: 125 psi
• System Connection Size: 2 inches
• Top Connection: 1/2 inch NPT
• Additional Tapping: 1/2 inch NPT
• Length: 8 inches
• Width: 3.5 inches
• Height: 5 inches
• Compatible Equipment: 700 Series Automatic Air Vents and Extrol Expansion Tanks
• Compliance: Low Lead IAPMO