Air Valve Manufacturer in Germany

Air valves manage accumulated air and vacuum conditions in pressurized water pipelines. They discharge large volumes of air while a system is filling, admit air when the pipeline is draining and, in combination designs, release smaller air pockets that collect while the line remains under pressure.

Air Management in Water Pipelines

Air can enter pipelines during filling, through pumps, through leaks under negative pressure or as dissolved air comes out of solution.

Uncontrolled air pockets can cause:

• Reduced pipeline capacity
• Increased pumping energy
• Flow instability
• Measurement errors
• Pressure transients
• Corrosion at air-water interfaces

Air valves are installed at selected pipeline locations to discharge or admit air according to changing system conditions.

Air Release, Air/Vacuum and Combination Designs

Air Release Valve

An automatic air-release valve removes relatively small volumes of accumulated air while the system remains pressurized.

Air/Vacuum Valve

An air/vacuum valve uses a large orifice to release bulk air during pipeline filling and admit large volumes of air during draining or negative-pressure conditions.

Combination Air Valve

A combination valve incorporates both large-orifice air/vacuum operation and small-orifice automatic air release.

This allows one valve to manage:

• Pipeline filling
• Normal pressurized operation
• Pipeline draining

Large Orifice and Small Orifice Operation

• During pipeline filling, large quantities of air must leave the system without generating excessive backpressure. The large orifice remains open until rising water lifts the float and closes it.
• During normal pressurized operation, accumulated air collects inside the valve body. A smaller automatic air release mechanism allows this air to escape without releasing significant quantities of water.
• During draining or a negative pressure event, the large orifice opens and admits atmospheric air into the pipeline.
• Correct coordination of these functions is important for pipeline surge and vacuum protection.

Technical Specifications

Air Valve Sizing Requirements

Air valve size should not be selected from pipeline diameter alone.

Required data includes:

• Pipeline diameter
• Filling rate
• Draining rate
• Maximum allowable differential pressure
• Pipeline length
• Elevation profile
• Pump flow rate
• Expected vacuum condition
• Surge-analysis results

Large orifice sizing determines how quickly air can leave or enter the pipeline.

Small orifice sizing is based on the volume of accumulated air that must be released while the pipeline is under pressure.

Pipeline Positioning and Installation

Air valves are commonly installed at:

• Pipeline high points
• Major changes in gradient
• Long rising sections
• Downstream of pumps where air accumulation is expected
• Upstream or downstream of control-valve locations according to hydraulic design

An isolation valve should normally be installed beneath the air valve so that maintenance can be performed without draining the entire pipeline.

The valve should be installed vertically unless the specific design permits another orientation.

Discharge outlets should also be positioned to prevent released water or contaminated fluid from creating a safety hazard.

Water Transmission and Pumping Applications

Typical applications include:

• Drinking-water transmission
• Distribution networks
• Pumping stations
• Sewage pipelines
• Effluent systems
• Desalination plants
• Irrigation networks
• Raw-water mains
• Firewater networks
• Industrial water systems

Correct air management improves hydraulic capacity and reduces the risk of vacuum conditions, but air valves should be selected as part of the complete pipeline surge and hydraulic design.