We receive an average of 3 questions a day asking us if we can help with an airline fitting problem. Most revolve around the question of compatibility with existing fittings or connectors on air tools, compressors etc.
This short guide has been put together to try and give quick online help to these common questions.
There are hundreds of different types of air fittings but most air tools use one of just a few types of connector.
The main things to consider are the fitting type and the thread size.
Most buyers are looking to find simple replacement fittings or fittings to use with a new tool or compressor.
These types of air line fittings are sometimes given other names in other regions or parts of the world. They are not interchangeable and we often advise buyers to 'start again' with a single type to ensure future compatibility and certainty. Euro fittings have bodies which are typically around 20mm long. Much shorter than the Standard/Airflow/Type 19 fittings. Similar fittings to Euro fittings are often found on air tools from the far east, they look very similar but are not compatible.
One of the most common types of fittings in the UK is the Standard fitting, sometimes called Type 19 or Airflow. This fitting can be used with PCL Standard and Vertex couplings. Due to their double action mechanism Vertex couplings are ideally suited to trailing airline applications such as air lines in garages.
These quick release couplings have a double action feature which makes them ideal for trailing hose applications in garage and tyre bay environments (e.g. portable air tools and hand held tyre inflation equipment).
Threads are generally BSP or British Standard Pipe. A 1/4" BSP thread is typical but don't think it has any measurement of 1/4" is doesn't!
What is the difference between BSPT and BSP (or BSPP)? The other important thing to know is that airline connector threads are either parallel (P) or taper (T). As the name suggests the taper thread has a diameter which tapers towards the end. This can be used to improve the airtightness of the connection. An alternative method would be to use PTFE thread sealing tape.
Other common thread sizes include 1/2" BSP and 3/8" BSP.
Threads are also described as either male or female - A male thread is an external thread and a female thread is an internal thread. Gender Changers and Reducing Unions are widely available.
Airline hoses will be supplied with a range of threads so take care when ordering fittings to go with them.
Airline hoses will be supplied with a range of threads so take care when ordering fittings to go with them. It can be a good idea to buy kits of hoses with fittings to ensure you get the correct fittings for the hose.