An air chuck, by definition, is simply a device that is used to hold an object in place while it is being worked on by a pneumatic machine, such as an air compressor.
One of the most common types of air chuck is a tire chuck. Tire air chucks connect to the stem or hose of a tire gauge, inflator, or air compressor. The tire chuck holds the air line onto the tire valve stem, so that air can flow freely between the tire and tool being used to check, inflate, or deflate tire pressure.
There are two types of air chucks - open flow and closed flow. In this blog post, we will discuss the differences between them, and in what situations you should use an open flow vs. closed flow air chuck for tire pressure maintenance.
What is the difference between open and closed flow air chucks?
Open Flow
Open flow air chucks are the most common type of chuck. They allow the air to pass freely through the fitting, even if the chuck is not engaged with the tire valve stem. Open flow air chucks are required for use with hand-operated tools such as tire gauges and inflators, or for tankless style 12-volt air compressors.
Closed Flow
Closed flow air chucks feature internal "check valves" that do not allow air to flow to or from the chuck unless the chuck is engaged with a tire valve stem, which makes them more efficient for using directly on an air compressor hose line, since they will not rapidly deplete the air tank unless engaged with a tire valve stem.
How do you know which type of air chuck to use for a particular job?
When choosing an air chuck, it is important to consider the type of job you will be using it for.
- Open flow air chucks are typically used with tire gauges and inflators
- Closed flow air chucks are typically used directly on the end of an air compressor hose line (see below image)
Can you use an open or closed flow air chuck with a compressor?
Yes, you can use either an open or closed flow air chuck with a compressor. However, when using a compressor, it is important to choose an air chuck that is compatible with the type of compressor you are using.
Different Types of Air Compressors
12-volt Tire Inflators
Portable tire inflators are an excellent choice for those who have limited storage space or want to take their vehicle on trails without having too much equipment. This type of power source works best with open flow chuck chucks because there's no need for tanks, so using a closed-flow unit would only build up pressure which could damage the motor over time!
Air Compressors with Tanks
The compressors you'll find in automotive shops, garages and workshops are usually of the "pancake" or “hotdog” styles. They have a built-in tank for holding air which can be disconnected from its hose when not needed so it doesn't take up space on your workshop!
With these types of compressors, you will want to use a closed flow air chuck unless you have an hand-operated tire inflation tool, such as a tire inflator gauge that can control the flow of air to and from the compressor. Using an open flow air chuck directly on the airline of these types of compressors will rapidly deplete the air from your tank!
TLDR;
- Open flow air chucks do not have a check valve, so they allow air to flow freely through even when not engaged with a tire valve stem. These are commonly used with tire inflators and tire gauges, since they do not allow air to build up in the tool.
- Closed flow air chucks feature an internal check valve that does not let air pass through unless engaged with a tire valve stem. These are best used as a standalone fitting directly on the end of an air compressor hose line, since they will not drain the air tank.
