Valve Pit l Vacuum Mains l Vacuum Station
Vacuum sewers use small diameter PVC pipe installed in shallow trenches. Vacuum mains are slightly sloped towards the vacuum station. In flat terrain, a vacuum main can be extended 2+ miles from the vacuum station. Click here for more information regarding line sizes, slopes and line lengths.
Profile changes, called lifts, are used to minimize trench depth. The line profile is designed to ensure that sewage will not block the pipe at low flow periods when the sewage is at rest.
"We liked AIRVAC because it did not require large pipes nor deep burial depths." - Paul Moore
"With vacuum you can “field engineer” in some cases. You can actually redirect the line for a few feet to get around an obstacle such as a tree or buried utility you didn’t know was there. You can’t do that with a gravity sewer.” -Chuck Brunkart
Click Here to find out what more of our customers are saying about AIRVAC!
AIRVAC’s patented saw-tooth profile keeps sewer lines shallow. Vacuum mains are typically installed within 1-2 ft of the minimum trench depth required by code.
Line lengthThere is a potential vacuum loss associated with every lift. This limits the length of each vacuum main to about 2 miles (3 km) in flat terrain. Elevation changes along the route can extend or reduce this range.
SlopesVacuum mains are slightly sloped (0.20%) towards the vacuum station. Velocity in a vacuum main is independent of both slope and pipe diameter, unlike gravity sewers that require a minimum slope for a given pipe diameter to obtain the 2 ft/sec scouring velocity. The pressure differential results in velocities of 15 to 18 ft/sec.
Line sizes are typically 4”, 6”, 8” and 10“ (100 to 250 mm) SDR 21 gasketed PVC pipe. PE pipe can also be used.