Application: | Main Vent |
---|---|
Size: | 1/2" x 3/4" |
Type: | Non-Vacuum Float-type Vent |
System Type: | Steam |
Max Pressure: | 15 psig |
Max Operating Pressure: | 3 psig |
Mount: | Straight |
Adjustability: | Non-Adjustable |
Material: | Steel |
Body Pattern: | Straight |
Thread Type: | Female Male |
Max Temp (F): | 240°F |
Temperature Range (F): | 140°F - 240°F |
Min Temp (F): | 140°F |
Thread Size: | 3/4" 1/2" |
Good AM The Hoffman model 75, p/n 401434, is 5-5/8" tall overall. Michael Milawski Associate Director of Physical Plant SUNY Downstate Medical Center
Air Valves perform two important functions in a piping system. They maintain system design efficiency and provide system protection. Air valves do not need to be changed as long as they are functioning properly.
This valve vents cool air from the radiator system to help the steam circulate. When the air heats up, the valve closes so no steam leaks out. These valves last for years, but eventually stop working. I have heard that they last 10 to 15 years, but do not know. When they stop working, they will remain open all the time, and will leak steam into the house throughout the whole steam cycle.
This vent removes steam and hot air pockets from the condensate return lines in a closed loop steam heat system. That is, steam goes out to your radiators to heat your building. As the steam gives up its heat to warm your room, the steam condenses into hot water, which returns to the boiler to be re-heated. For various reasons, steam may sometimes also return with the hot water, as well as air bubbles. These pockets can block the flow with pressure, cause your boiler to be full of air, or damage your pipes. This vent lets the steam and hot air out, but keeps the hot water in. If properly placed and sized, this vent should last for decades.