霍夫曼专业水排气阀型号77, 78, 79
Hoffman Specialty Water Vents Model 77, 78, 79

Model 77 Part No. 401497 Water Vent Valve

• For efficient releasing of air in hydronic heating systems, such as baseboard radiators, convector radiators and small heating units
• 1⁄8″ NPT straight shank
• Maximum operating pressure 50 psig (3.5 bar)*
• Maximum temperature 240°F (116°C)

Model 78 Part No. 401485 Water Main Vent Valve

• For use on high pressure hot or cold water or glycol mains and process applications with specific gravity
• greater than 0.7
• Cast brass body
• Tapped at top for 1⁄8″ NPT safety drain connection for discharging moisture
• Body unscrews for easy cleaning
• Built-in Check Valve
• 3⁄4″ NPT straight shank
• Maximum operating pressure 150 psig (10.3 bar)*
• Maximum hydrostatic pressure 450 psig (31.1 bar)
• Maximum temperature 250˚F (121˚C)

Model 79 Part No. 401488 Water Main Vent Valve

• For use on hot or cold or glycol water mains and process applications with specific gravity greater than 0.7
• Tapped at top for 1⁄8″ NPT safety drain connection for discharging moisture
• Removable top
• Built-in Check Valve
• 1/2″ NPT female and 3⁄4″ NPT male straight shank
• Maximum operating pressure 75 psig (5.2 bar)*
• Maximum hydrostatic pressure 200 psig (13.8 bar)
• Maximum temperature 250˚F (121˚C)

*Drop away pressure (maximum pressure against which the vent can open).