Val-Matic Air Valves to the Rescue

The water supply distribution system consists of pipelines that help get water and wastewater from point A to B. Purging air from the pipeline is necessary because trapped air significantly reduces pump and/or pipeline efficiency and life. This can cause surges/water hammer and accelerated corrosion. Air is sometimes removed from the line with a manual vent or fire hydrant during initial start-up, but this method does not provide continual air release during system operation, nor does it provide vacuum protection. Today, municipalities use a variety of automatic air valves at the pump discharge and along the pipeline.


Air valves are hydromechanical devices designed to automatically release air and wastewater gases or admit air during the filling, draining, or operation of liquid piping systems for water and wastewater services. This part can be installed in numerous applications from local peaks in a system and changes of the pipe diameter to street underpasses and by filter installations. Advantages of an air valve includes the following:


  • Reduces corrosion
  • Decreased energy consumption and operation costs
  • Increased accuracy in flow metering
  • Reduces the delay time for filling of mains, which increases the efficiency of the pump and pipeline
  • Decreases the risk of water hammering
  • Sudden movement of air pockets can result in a rapid change in the flow velocity, leading to high pressure surges of a destructive nature. By decreasing air pockets in the pipeline, this also reduces the chance of a surge.


There are three basic types of air valves standardized in the American Water Works Association (AWWA) Standard C512-15:

  • Air Release
    • Releases relatively small quantities of air from a pressurized line as needed
    • Also known as a small orifice air valve and as a pressure air valve
  • Air/Vacuum
    • Discharges large quantities of air from non-pressurized pipes and are used mainly when filling a line
    • Also makes it possible to admit large quantities of air when lines are drained and when the pressure drops suddenly
    • Also known as kinetic valves, large orifice air valves, vacuum breakers, low pressure air valves, and air relief valves
  • Combination Air Valve
    • Fulfills the tasks required of both types of valves – air release and air/vacuum
    • Discharges or intakes large volumes of air when filling or emptying a system and releases small volumes of air when the line is pressurized as needed
    • Also known as double orifice air valves, double acting, or dual orifice


The Val-Matic Air Release Valve and Combination Air valve are manufactured in accordance with rigorous industry requirements given in the AWWA Standard C512. Each valve features a 316 stainless-steel trim, full size port, ANSI threaded or flanged connections, and stringent testing. From the float material to the shape of the body, Val-Matic Air Valves are designed for optimum performance. Both valves are NSF 61 and 372 certified for use in drinking water applications. Keep reading to learn the features and benefits surroundings Val-Matic’s Air Release Valve and Combination Air Valve:


Val-Matic Air Release Valve

Val-Matic Combination Air Valve

Operational highlights:

  • Maintains system flow efficiency
  • Releases unwanted air pockets during system operation
  • Protects system against air related surges
  • Fully complies with AWWA C512

Product features:

  • Unconditionally guaranteed stainless-steel floats
  • Stainless-steel 316 internal trim
  • Resilient seating for positive shutoff
  • Performance proven for over 50 years

Optional accessories:

  • Vacuum check (prevents inflow of air)
  • Outlet hood with screen (prevents debris from entering valves)
  • Isolation ball valves (allows valve maintenance)

Operational highlights:

  • Provides the functions of both Air Release and Air/Vacuum Valves
  • Exhausts large quantities of air at system start-up
  • Provides pipeline vacuum protection
  • Fully complies with AWWA C512

Product features:

  • Single body incorporates both features within one valve
  • More compact and economical
  • Inlets and outlets are equal to full nominal size
  • Unconditionally guaranteed stainless-steel floats
  • Stainless-steel 316 internal trim
  • Exclusively high/low pressure resilient seating

Optional accessories:

  • Outlet hood with screen (prevents debris from entering valves)
  • Isolation ball valves (allows valve maintenance)


Learn more about Val-Matic Air Valves by taking the ‘Val-Matic Air Valves’ AYU course, calling our customer service department at 1-800-292-2737, or filling out a Contact Us form on