Learn about Air Fittings, Hose Connectors, and Quick Release Couplings

Although air hose fittings and connectors are small in size, they play a critical role in the overall performance of air compressors and their accompanying air tools. These fittings maintain a constant flow of air and pressure within the hose without affecting the performance of the air tools. Having durable and reliable air tool fittings and couplers is essential for the safe and efficient operation of pneumatic equipment. At CT AIR TOOLS, we offer high-quality air fittings and couplers that can help you expand your air supply system or create a more complex setup to meet your needs. To ensure optimal performance, it’s important to maintain your fittings in good working condition.

How Do Air Hose Fittings Measure?

Many of the hoses in our product line already come with end fittings installed, so you can immediately connect them to your air compressor and tools. Any additional couplers you need will typically match the same size as the existing fittings.

If you’re unsure of the size you need, it’s simple to determine. The circumference of the hose corresponds to the size of the fitting. Here's a quick method to calculate the circumference:

1. Take your hose and a piece of string.
2. Wrap the string around the hose.
3. Mark the ends of the string.
4. Place the string next to a tape measure and measure the length.
5. Divide the length by Pi (3.1416) to find the diameter of the hose.

Most pneumatic tools use a few standard types of connectors, with the main considerations being the fitting type and thread size. Common fitting types include ?” BSP, ?” PCL, and 3/8” NPT.

What are BSPF and BSPM?

British Standard Pipe (BSP) is a series of internationally recognized thread types used to connect and seal pipe ends. Male threads connect to female threads, and the thread size is measured from the inside of the fitting. When a fitting is marked "Female Quick Release to 1/4” BSPM," the "BSPM" indicates a British Standard Pipe Male Fitting. Conversely, if the fitting connects to a female thread, an "F" will appear.

Can You Connect Two Air Hoses Together?

Most hoses come with threaded fittings or quick release couplings. Male threads screw into female threads, and male quick releases plug into female quick releases. If you need to connect two hoses, you’ll likely need an appropriate fitting. Fortunately, we offer a wide range of fittings, and any CT AIR TOOLS air compressor or hose uses ?” BSP threads or quick release fittings for easy connections.

Technically, there’s no limit to the length of hose you can use with fittings. However, it’s generally better to use one long hose rather than connecting multiple hoses. More connections increase the likelihood of a pressure drop.

Should I Use Teflon Tape on Air Fittings?

It’s a good idea to use Teflon/PTFE tape on threaded fittings, but quick release fittings don’t require any additional sealant. These fittings rely on an internal o-ring to seal when disconnected. If you experience a leak with a quick release fitting, it may be due to an incompatibility or a damaged/missing o-ring. Many fittings look similar, so a leak could simply be caused by using the wrong type.

What are Quick Release Fittings?

Quick release fittings make it easy to connect and disconnect your air compressor or tools from the air line. These fittings are designed to seal with an internal o-ring, eliminating the need for a shutoff valve. Quick release fittings consist of male and female parts, and when connected correctly, they hold internal pressure.

These fittings also allow for movement, which reduces kinks and twists in the hose, making them ideal for busy job sites and contributing to a safer work environment.

What are PCL Couplings?

PCL fittings are disconnected by pulling back on the collar while keeping the air hose or tool connected. This can cause the air hose to flutter as compressed air escapes, so it's best not to perform this in busy areas. PCL couplings are ideal for stationary applications, such as bolting directly to a compressor. However, it’s important to note that PCL fittings are not compatible with BSP fittings.

What is a Hose Tail?

Hose tails are used to connect fittings to hoses or even to connect two hoses together. Always ensure that you select the correct hose tail size based on the hose ID and secure it with a Jubilee clamp.

What to Consider When Choosing a Coupling

When selecting a coupling, consider the following factors:

• What type of coupling do you need? Is it ?” BSP, ?” PCL, or another type?
• What is the maximum pressure (in PSI) that the air coupler/plug can handle?
• Some couplers may require PTFE tape to create a seal.
• Check the temperature ratings of the coupler.
• How long will the coupler last? All CT AIR TOOLS couplers come with a 1-year warranty!