Brochure

90
Vents
Model 78 Part No. 401485
Water Main Vent Valve
• For use on high pressure hot or coldwater 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 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)
Water Vents
Water Vent Valve
Model 77
3
1
/4"
(83mm)
1
1
/2"
(38mm)
5
/8"
(15.9mm)
2
11
/16"
(68mm)
6
1
/2"
(165.1mm)
Water Main Vent Valve
Model 78
*Drop away pressure (maximum pressure against which the vent can open).
How to Select Water Vents
Built-in Maximum
Model Radiator Convector Vacuum Operating
Number Mains Check Pressure Remarks
psig (bar)
77 XX 50 (3.5) Small Systems
78 XX150 (10.3) High Pressure
79 XX75 (5.2) Low Pressure
790 X 30 (2.1) Small Systems
791 XX 50 (3.5) Small Systems
792 X 250 (17.3) Cast Iron Body
550 X 100 (6.9) Air Chamber
508 XX 50 (3.5) Moisture Type
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)
6
5
/8"
(168.3mm)
2
1
/2"
(64mm)
Water Main Vent Valve
Model 79
Hoffman Specialty
®
Vents