What is an air release valve?

Most of the water systems consist of an air release valve. For instance, an irrigation system consists of pipelines that transport the water from one point to another. During the process, the water cavities are formed which disrupts the flow. At this point, the air release valve comes into the picture.

The air release valve uses an internal lever mechanism which aids it to open against the internal pressure built due to the air inside the pipeline. The internal lever mechanism multiplies the float force and surpasses the internal pressure. This, in turn, leads to the opening of the orifice where air pockets are collected in the valve.

Functions of air release valve

The air release valve is basically used to release the entrapped air inside the pipeline. They are designed to automatically release the air or wastewater gases when the pipeline uses the water services. It does not only release the air in the atmosphere but also sources the air into the piping system at the leaky point or when the pipeline is operating below atmospheric pressure.

The usage of an air release valve ensures the smooth functioning of the pipelines and improve the life of the system. It maintains the water flow in the right direction which is vital for the effortless functioning of the pipeline. This means that it avoids the backflow of the water. In addition to this, it reduces the pressure of the water in the system.

What if the air release valve is not installed in the system?

  • Leads to complete stoppage of water flow.
  • Energy losses in the system
  • Corrosion and cavitation in the pipeline.
  • Water hammer which causes serious damages to the pipes
  • Inaccurate readings on automatic metering valves

3 Basic Type of Air Release Valves

According to the American Water Works Association (AWWA), there are three basic types of air release valves.

Here below are the types

  1. Automatic air release valve with a small orifice

In this type, the orifice size ranges between 1.6mm and 13mm. It has a lever mechanism which helps in opening the orifice when air is accumulated near it. These air release valves are designed to automatically release the small air pockets when the pressure inside the pipe exceeds atmospheric pressure. This type is usually installed at higher points or at the point where the grade changes within the pipeline system.


  • Water transmission lines
  • Sewage lines
  1.  Air and vacuum valves with large orifice

This type is designed to exhaust a large quantity of air during the pipeline filling period or to insert a large quantity of air if the air inside the systems drops below the atmospheric pressure. The air and vacuum valves are equipped with an anti-slam device to control the flow of the water. The valve is usually open and reveals the large orifice. In this type, the residual air pockets might still remain while the pipeline is in the operation but the float will remain closed to the seat due to the internal pressure.


  • Sewage force mains
  • Water transmission lines
  • Combination air release valves

It’s a combination of air release valve and air & vacuum valve. During the operation, the large (air & vacuum valve) and small (air release) orifices are open during the filling of the water. In this case, the majority of the air passes through a larger orifice. The combinational air release valve came into existence due to the flaws in the afore-mentioned valves.

The small orifice valve does not admit a large quantity of air which can cause vacuum formation. Meanwhile, the larger orifice valve allows purging large volume quantity of air. During the operation, they can’t release the small air pockets in the atmosphere. Thus, to perform both the functions, a combination air release valve is installed in the system.


  • Water mains
  • Deep well turbine pumps
  • Transmission lines
  • Sewage water mains

Application-based Air Release Valve

The general size of the orifice in the air release valve ranges between 1/16’’ and 3/8’’, depending on the valve design or application.

  • Heating/Air Bleeder Type

The air bleeder valve ejects the trapped air from the heating system. The air trapped in radiators, pipelines, baseboard, and convectors can be easily removed by an air bleeder valve. If the value is not installed, the system starts making the system bubbling sounds or become noisy. This valve comes into action when the boiler is running hot while the convector or radiator is still cold. This is the time when the bleeder valve ejects the air out.

This bleeder valve type is available in manual and automatic options. The automatic air bleeder valve is fitted at the upper level in the building or at the boiler. In the case of manual type, these valves are usually located at heating radiators and convector units. In both cases, the entrapped air is removed via heating distribution pipes. This valve is basically used for the maintenance and safety operations of the heating systems.

  • Rapid Venting Type

This is a specialized air release valve utilized to remove the initial air from pipelines carrying fluids. They have a large-size valve seat which aids in rapidly discharging the initial air. The float in the valve responds with sound sensitivity which eliminates the need for manual labor. This product type does not have any hinges or levers which makes it easy to design. In this type, the float is the only moving part.

The rapid venting type is used in water lifting systems, water storage tanks, holding tanks, and hot water tanks, among others. This type carries non-flammable fluids. Most of the products available in the market are made up of cast iron or stainless steel. The rapid venting air release valve will only open again when the water level in the pipe approaches the vacuum conditions.

There are different types of air release valves which are designed for special purposes such as pressure relief valves, degassing valves, and vacuum breakers, among others.

3 Industry Trends That’s Driving the Growth of the Market

As per the market research by Growth Market Reports, the global air release valve market size was around USD 1.17 Billion in 2019 and is expected to at least USD 2.025 Billion by 2027, expanding at a CAGR of minimum 7% during the forecast period 2020-2027.

  1. Rising demand for water and wastewater management facilities

The world’s population is rising at a steady rate which is surging the demand for clean water across the globe. This has persuaded the state government and municipality bodies to take initiatives to deploy systems that manage the water effectively. They’re installing mechanical wastewater treatment to eliminate solid waste and drain out bio-waste through sludge activation tanks. All these water treatments and management require the installation of an air release valve in the system.

Government bodies are hiking investments in wastewater treatment plants and are refurbishing the broken/old pipelines. Moreover, they’re creating additional water supplies to cater to the demand for the urban population. Governments are issuing stringent norms on the water treatments as water pollution has witnessed an upward graph in recent years. According to the research, the wastewater treatment market is anticipated to grow at a healthy rate of at least 5% during the forecast period which is expected to eventually foster the growth of the air release valve market.

  1. Stringent Safety Regulations Across Globe

The explosion of compressed pipelines can lead to severe damages to human life and surroundings. Furthermore, it can incur a lot of costs to government state bodies and private organizations. Thus, to avoid both, the government and various organizations have implemented several workforce regulations across the globe. This has surged the demand for air release valves in various industries.

  1. Demand for Low Maintenance Systems

The installation of an air release valve reduces the maintenance frequency. This reduces the costs and purchase of spare parts. Moreover, it improves performance, reduces leakage, and cut overhead energy loss. This eventually reduces power consumption and saves a significant amount of money for the government or private organizations.

4 Leading Companies & Their Developments in the Air Release Valve Market

  1. Flomatic Corporation

The global manufacturer and distributor of air release valve have launched various products over the years to expand its market share across the globe. It has air release valves products for clean water and sewer water applications. The sizes available are between 10 and 50mm. Along with the air release valves, it has a broad product portfolio which includes a plug valve, gate valve, automatic control valve, and VFD valve among others.

In September 2020, the company expanded its AIS complaint Model 408 Ball Check Valves with new size which is 8’’ & 12’’. Its products are widely used in water and wastewater management facilities across the globe. In August 2020, Flomatic announced the expansion of its expanding AWWA Swing Check valve family with the 10’’ AIS complaint Model 92.

  1. AVK Holdings A/S

The UK-based utility and waste treatment company designs and manufactures valves, hydrants, and accessories for the water and gas industry. AVK has a double orifice valve designed for rapid pipe filling and pipe draining operations. Moreover, it is utilized for the discharge of accumulated air for drinking conditions. The company also has an automatic valve that enables the effective discharge of air under the pressure. Along with this, it has a combinational valve which admits and discharges a large quantity of air.

Most of its products are bonded with EPDM rubber which ensures long-term maintenance-free operation. Furthermore, it has a body of ductile iron with fusion bonded epoxy coating which is a complaint to DIN 3476 part 1 and EN 14901.

In September 2019, the company introduced UL and FM gate valves for fire protection applications. To stronghold its market position, AVK acquired the Norwegian company Furnes Jernstoperi, a prominent producer of manhole covers. In the same year, the company acquired ACMO, an Italian company whose product portfolio includes control valves, check valves, and air valves.

  1. Val-Matic Valve & Mfg. Corp

The U.S.-based air valve company manufactures air release valves for clean water and wastewater. All its products are manufactured under a certified ISO 9001 quality system. They are NSF 372 and NSF 61 certified while approved for fire services. Moreover, its air release valve also meets AWWA C512 rule.

The company’s air release valves are made up of T316 stainless steel floats and are available in size range of between ½’’ and 6’’. It produces products for various industries including sewage treatment, water treatment, and waste distribution. Over the years, the company has expanded its product line in butterfly valves, check valves, and plug valves, among others.

  1. Cla-Val

The prominent manufacturer of automatic control valves has been expanding its product portfolio and market share since 1936. Cla-Val has listed two products under the air release valve segment. Its first product- 33A Air Release & Vacuum Breaker Valve can be utilized for water treatments, vertical turbine pump discharge, and transmission pipeline high points.

The company’s other product- 34 Air Release Valve is UL Listed and FM approved. It can operate under the working pressure of up to 800 PSI. This product can be easily repaired without its removal from the pipeline.

Other prominent companies include E. Hawle Armaturenwerke GmbH, Braeco, Bermad Water Technologies, RF Valves, Tecofi, and VAG GmbH, among others. The leading companies are engaging in continuous product developments and are heavily investing in R&D activities. Besides this, they’re partnering and collaborating with other companies to expand their market share.

Market Segmentation

Based on the product type, the market is segmented into air bleeder and rapid venting. In 2019, the air bleeder type accounted for a significant market share and is expected to exhibit a high CAGR during the forecast period. In terms of applications, the market is divided into irrigation, water treatment, building & fire systems, and others. The water treatment segment contributed a high revenue share to the market and is anticipated to continue to do so in the foreseeable future.

The market is further classified into sales channels such as dealers/distributors, independent retailers, online platforms, and others. In 2019, dealers/distributors accounted for the largest market share and are anticipated to continue the trend during the forecast period. On the basis of geographical location, the market is segregated into North America, Europe, Asia Pacific, Middle East & Africa, and Latin America. The market in the Asia Pacific is predicted to witness a higher CAGR in the coming years. The rapid urbanization and increasing government investments in the water management facilities are catapulting the demand for air release valve in the market.