Locating air valves along a force main lift station manhole pumps operating and line is full air release air release.
Air release valve force main.
Sewers force main description force mains are pipelines that convey wastewater under pressure from the discharge side of a pump or pneumatic ejector to a discharge point.
In this application the opening of the check valve is delayed with a timer until the air release valve can discharge the air in the pump column to achieve a controlled 1.
Pumps or compressors located in a lift station provide the energy for wastewater conveyance in force mains.
The key elements of force mains are.
Negative pressure valvepressure air release valve midget valve low.
An air release valve can open against internal pressure because the internal lever mechanism multiplies the float force to be greater than the internal pressure.
Sometimes they might be slightly downstream or paired with a combination air valve.
3 design the top of the force main and its appurtenances such as air release and air and vacuum valves lower than the hgl.
Air release valves arvs are used to help resolve air entrapment issues.
Air release valve arv and manhole are common locations where odor complaints can originate due to the production of h2s gas in the force main conveyance systems.
An air release valve can be used between a vertical turbine pump and a power actuated pump check valve to prevent surges in the piping between the pump and the check valve.
Combination air valves perform the functions of an air vacuum valve exhaust large quantities of air on start up admits air on shut down and air release valves release air continuously during operation to maintain system efficiency and prevent pipeline surges.
Water pipelines and sewer force mains are popular areas to find air release valves.
If correctly installed you should see them at the peaks and high points of the system.
Arvs are typically located at high point elevations in force mains.
High points lift station manhole potential vacuum pumps stopped and line is draining.
While the problems exists the damage by not fixing the issues at the source will remain for years and begin to degrade your equipment beyond repair.
The arv released any entrapped air caught at the high point of the system see image below 1.
2 show the hgl on the profile for the design of the force main or provide a table on the plans providing the hgl elevation every 50 feet along the length of the force main.
