Armstrong International D500631 3/4" 21-AR Air Vent 133 PSI

The Armstrong International D500631 is a 3/4-inch 21-AR series automatic air vent designed for steam and hot water systems. This air vent features a 5/64-inch orifice and is rated for working pressures up to 133 PSI, making it suitable for medium to high-pressure applications.

Key Features:

• 3/4-inch NPT threaded connection for easy installation
• 5/64-inch orifice size for efficient air removal
• Maximum working pressure of 133 PSI
• 21-AR series design with thermostatic operation
• Automatic venting eliminates air pockets that reduce system efficiency
• Durable construction for reliable performance in steam and condensate systems
• Helps prevent water hammer and improves heat transfer

Armstrong International's 21-AR air vents are essential components in steam distribution systems, automatically releasing non-condensable gases while preventing steam loss. The thermostatic element closes when steam is present, ensuring efficient operation and energy savings.