If you have an air hose and need to install a permanent system or replace the fittings, you need to think about the size and type of fittings the system needs. Most air hoses for sale have standard fitting sizes, but it is essential to understand the common measurements that come into play. Air hose couplings and connectors use the NPT fitting standard, which means if you are choosing equipment measured with standard fitting, then it is compatible with the other fittings. Next is a guide to help you select the right fittings.
The Style of the Fitting
There are different styles of air hose fittings, i.e., A-style to T-style fittings hence, the need to choose the right one to ensure a secure fit. Some plugs are designed for A-style hoses while other styles (A/M/T) accept all the popular ¼ basic style plugs.
The fittings are usually manufactured according to the National Pipe Taper standardisation system. As such, the fitting should have the same dimensional compatibility as the fittings made by other manufacturers. Consequently, users can easily buy an air hose from another manufacturer as long as the dimensions are the same as the NPT standard.
Sizing Information and Dimensions
NPT sizes vary widely, and so, a fitting measuring ¼ inches isn’t the same as a ¼ inch diameter. Its actual diameter is close to half an inch. A fitting measuring an eighth, on the other hand, is equivalent to 5/16 in diameter size and two-inch NPT is equal to 2 3/8 in diameter. Instead of committing to memorise the diameters of the fittings, use the NPT chart to find the best size for your device. You can measure the diameter of the hole in inches and compare the measurement to the fractional sizes on the NPT chart to choose the appropriate fitting. Standard thread sizes for the NPT include ¼ NPT, 1/8 NPT, 3/8 NPT and ½ NPT.
Other Features to Consider
The maximum inlet pressure: Also referred to as the PSI, it shows the maximum amount of pressure the plug can withstand:
- The seal: Most seals are tapered and fastened to create a fluid-tight seal. Some allow users to increase the seal manually by adding a liquid thread sealant or Teflon tape. If you are using the air hoses in unusual high-pressure environments, be sure to choose a fitting suitable for that environment.
- The maximum temperature: The fittings withstand different amounts of temperature. The typical maximum temperature rating is 250 degrees Fahrenheit.