How Are Air Fittings, Hose Connectors, & Quick Release Couplers Used?

Air compressors, hoses, and other pneumatic tools are dependent on the connectors and other fittings they use to work effectively. The fittings are tasked with maintaining a constant flow of air and pressure within the hose so that the performance of the system is not compromised. Several major types of connectors you will see are quick release couplings, threaded fittings, PCL couplings, and hose tails. Having durable and effective pneumatic tool fittings is essential for the safe and efficient operation of your pneumatic instruments. In this blog, we will discuss the different types of fittings available and several key things to consider when choosing a coupling(s) for a specific project.

How Are Air Hose Fittings Measured?

Many air hoses will come already attached with some type of end fitting, and any additional couplers will need to be the same dimensions. If you are unsure what size you need, you can measure the circumference of your hose, which is also the size coupler that you will need. For example, if the diameter of the hose is a quarter of an inch, you can look for a size ¼” female quick release coupler. Besides sizing, the other two main things to consider are the fitting type and thread size. These will need to match the components you already have with the same threading, but opposite mating genders are used when applicable.

What Are BSPF and BSPM?

The British Standard Pipe (BSP) is a family of standard screw thread types that is used internationally for interconnecting and sealing pipe ends by connecting male with female threads. The thread size is measured and based on the inside of the hose fitting. An “F” or “M” on the end refers to the mating of the coupler connects.

Can You Connect Two Air Hoses Together?

Most hoses come supplied with either a threaded fitting or quick release coupling, and so, to connect another hose, you may need an additional coupling to connect the lines together. A male thread can screw into a female thread, whereas a male quick release can plug into a female quick release. By using a coupling, there is no limit on how long you can make a hose. However, it is important to keep in mind that with each new connection, the more likely it is that the line will experience a pressure drop. Therefore, it is always better to have a single, long hose than to have multiple smaller hoses connected together.

Can Teflon Tape Be Used on Air Fittings?

Teflon/PTFE tape is a good option for putting on threaded fittings to add an extra level of security without compromising flexibility. Conversely, quick release fittings are designed to seal using internal o-rings, so any additional tape or sealant is not required. Any leaks from a quick release coupling will likely mean that the o-ring is incompatible or damaged, and needs to be replaced.

What Are Quick Release Couplings?

Quick-release couplings are a type of fitting used to easily connect and disconnect hoses from an air compressor or pneumatic tool. They incorporate an internal o-ring that eliminates the need for a shut-off valve. These joints are also made of a female and male part which effectively contain internal pressure when properly connected.

What Is PCL Coupling?

PCL coupling can be detached by simply pulling back on the collar of the fitting while holding the air hose or tool that it is connected to. This can cause the hose to whip as the compressed air escapes so removal of this coupling should happen in a spacious environment. As a result of its single-action design, this coupling is ideal for fixed applications where it will not be regularly removed.

What Are Hose Tails?

Hose tails can be used to connect couplings to hoses, but may also be used to connect two hoses together. It is important that the size of these fittings match the diameter of their respective hose and that they are secured using a jubilee clip.


When choosing the right fitting for a pneumatic system, it is important to consider what removal method will suit your application along with the size and connector type of the parts you will be connecting them to. For a wide inventory of industrial parts including threaded fittings, sealants, and tapes, Industrial Parts Sphere is here to assist you with all that you require. We invite you to browse our catalog of available items on our website and submit a Request For Quote form (RFQ) to receive a competitive quote for your comparisons on any of the products we offer. Upon receiving and reviewing your form, our dedicated team will send you a quote catered to your specific needs in 15 minutes or less. Get started today to see how Industrial Parts Sphere can serve you as your premier sourcing partner!


December 15, 2022

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