Making sure that you use the right-sized air line fitting is the starting point of ensuring that you do not have leaks in your air line. And to be on the safe side, it is usually advisable that you use the National Pipe Taper (NPT) measurements when ordering a fitting. Since it is a universal standard, it won't really matter who the manufacturer is.
However, getting it right when it comes to the dimensions of a fitting's threads is sometimes not enough to prevent a leak. And when this happens, the following tips will come in handy in helping you to solve your problem.
Use a Teflon tape
A small piece of Teflon tape can help to improve the sealing between the threads at the connection point. It does so by providing room for the male threads to go deep into the female boss. And since the deeper the male threads go, the stronger the connection, the use of Teflon tape can help to solve a leak problem.
To do so, simply wrap a piece of the tape around the male thread. Take care not to wrap too much tape on the thread because doing so will make it impossible for the threads to turn. Finding the perfect number of wraps is a matter of trial-and error. The only thing that you should keep in mind is that the goal is to allow the male thread to turn deeper into the female. Simply having a tight seal is not enough.
However, a Teflon tape, while effective in creating a tighter seal, can also come with its set of problems. Parts of the tape can lodge in openings. Use of the tape can therefore cause blockages. Pieces of the tape can also create leakage problems when they stick onto a sealing surface, preventing it from sealing properly.
To be on the safe side, make sure that the tape is wound away from the end of the fitting such that when tightening the threads, the risks of the thread overlapping the fittings are minimal.
Use a liquid sealant
If you don't want to deal with the complications that come with using Teflon tape, you can use a liquid thread sealant. Apply it to the fittings, right before threading them. The additional sealing properties of the sealant will help to eliminate any chances of leakages.
Use doped air fittings as an alternative
Applying a thread sealant and using Teflon tape to help in the thread sealing process takes effort on your part. If you don't want to waste time trying to figure out how much tape to use or how much sealant to apply, simply buy doped air fittings. They usually come already equipped with a sealing paste that usually evens out any micro-voids in the threads and thus allowing for better thread seals.
For more information, contact a local air fittings supplier, such as Fittings Inc.