Xylem 401485 Model 78 Water Main Vent Valve 3/4" NPT 150 PSI

The Xylem 401485 is a Hoffman Specialty Model 78 water main vent valve designed for hydronic heating and cooling applications. This high-capacity automatic air vent is engineered for use on high-pressure hot or cold water or glycol mains and process applications with specific gravity greater than 0.7.

Key Features:

• Cast brass body construction for durability and corrosion resistance
• 3/4" NPT male straight shank connection
• Built-in check valve prevents air from re-entering the system when pressure drops
• Tapped at top for 1/8" NPT safety drain connection for discharging moisture
• Body unscrews for easy cleaning and maintenance
• Top-mounted, replaceable seat and check valve assembly isolated from suspended dirt

Technical Specifications:

• Maximum operating pressure: 150 PSI (10.3 bar)
• Maximum hydrostatic pressure: 450 PSI (31.1 bar)
• Maximum temperature: 250°F (121°C)
• Dimensions: 6-1/2" inlet to outlet length, 2-11/16" width
• Glycol-ready brass and stainless steel construction

This high-capacity vent can handle up to 850 SCIM, making it the only vent in this category with published ratings. The Hoffman Model 78 is ideal for commercial and industrial hydronic systems where reliable automatic air venting is essential for system efficiency and performance.