Types Of Air Valves

Air valves are crucial components in various piping systems, helping to regulate air flow, release air pockets, and prevent vacuum formation. Understanding the different types of air valves and their functions is essential for efficient system operation. In this guide, we will explore the characteristics and applications of various air valves commonly used in industrial and municipal settings.

 

Air valves are crucial components in various piping systems, helping to regulate air flow, release air pockets, and prevent vacuum formation. Understanding the different types of air valves and their functions is essential for efficient system operation. In this guide, we will explore the characteristics and applications of various air valves commonly used in industrial and municipal settings.

 

 

Different Types Of Air Valves

 

Air valves can be classified into several types based on their functionality and construction. Each type serves a specific purpose in maintaining the performance and integrity of a piping system. The following are some of the most common types of air valves:

Function

Based on the functions they perform on the pipeline, there are three types of Air valves:

Air Release Valve

Air release valves, also known as air vents or automatic air valves, are used to release excess air from pipelines to prevent air pockets from forming. These valves automatically open when air accumulates in the pipeline and close when the air is released, ensuring that the system operates efficiently.

Air/ Vacuum Valve

Air/vacuum valves, also known as large orifice valves, are automatic float operated valves. Air/vacuum valves are designed to release air from pipelines during filling and allow air to enter the system to prevent vacuum formation during draining.

Air/vacuum valves are installed downstream of the pump and at high points to vent large amounts of air during pump startup and pipe filling. The valve also allows large amounts of air to enter to prevent vacuum conditions in the pipe and allow drainage. When the air is exhausted, the float in the valve rises with the water level to close the valve. When pressure is lost due to drainage, line breaks, or column separation, the float drops and allows air to re-enter the pipe.

These valves are essential for maintaining system efficiency and preventing damage to pipes and components.

Combination Air Valve

A combination air valve performs the function of both the air and the vacuum valve. It is designed to both admit and release air as the situation requires.

Combination air valves can be made in single or double body form. On smaller valves, the float and lever mechanism are included in the one-piece design. For larger sizes, the twin-body design consists of a vent valve piped to an air/vacuum valve and is supplied as a factory-assembled unit.

Single units have the advantage of being more compact and often less expensive. The two-body unit facilitates exhaust valve sizing and maintenance because the air/vacuum valve remains in operation while the exhaust valve is isolated and serviced. By combining various sizes of exhaust valves and air/vacuum valves, two-body combination valves can be used in virtually any application.

Some designers only use combination air valves on piping because all air valve functions are included and errors in field installation will not leave the piping unprotected.

 

Body construction

We can also classify air valves using their body construction or the number of orifices (opening). Based on this classification, there are two types:

Single Orifice Valves: 

These valves have a single opening for air to enter or exit. They are simple in design and are commonly used in applications where air flow needs to be controlled or regulated.

Double Orifice Valves:

Double orifice valves have one large outlet and one small outlet. The large outlet admits air in large quantities while a pipe section is being drained. It's also responsible for venting out the air during the pipe filling operation. The small outlet is responsible for venting out small amounts of accumulated air during the pipeline's operation.