High Pressure Fitting Comparison

We get calls all the time from people trying to identify what they have on their high pressure lines.  Here are a few examples of high pressure fittings and their most common uses. 

1/8” NPT
This fitting is commonly used in paintball and some scuba applications.  The fitting is smaller in size and about the same size as a first stage regulator hose o-ring fitting. NPT stands for National Pipe Thread.  NPT will have a taper that starts at the end of the fitting and gets wider as it gets closer to the center.  They will usually be seen with Teflon tape on them.  Common applications are Aqualung Tank Checkers, Paintball, Quick Connects and actuator valves on compressors 

1/4” NPT
This is one of the most common sizes seen on blending whips.  The fitting is larger about the thickness of your small finger.  NPT stands for National Pipe Thread.  NPT will have a taper that starts at the end of the fitting and gets wider as it gets closer to the center. They will usually be seen with Teflon tape on them. NPT is common on most blending whips, compressor adapters, blowguns, air tools, lift bag valves and many others.

Swagelock
This fitting is usually seen in stainless steel.  It is used to join piping together.  The fitting consist of four pieces.  If we go left to right from the picture the first thing you will see is the fitting.  It can be a tee, a coupler, an adapter, an elbow or many others. The fitting will have a concave internal in the shape of a “V”.  The next piece is the thrust part, this is the other end of the “V”.  The next inline is the compression part of the fitting this part gets pushed into the “V” part of the fitting.  The last item is the nut.  The whole fitting is compressed onto the hose by turning the nut.  These are very secure fittings that are able to withstand continuous use at high pressures.  The swagelock fitting is commonly seen on compressor systems and some rebreathers. 

 JIC
This fitting is found in everything from brass to stainless steel. JIC uses the two “V’s” we described above.  The big difference is it is face contact not compression that does the sealing.  These are very common on whip systems of compressors as the inverted V can swivel so the long whip does not have to be spun around as it is put on. 

O-ring (SAE BOSS)
This fitting can be found in brass to stainless steel.  The fitting uses an o-ring to seal the high pressure gases.  These are not nearly as common and used mainly for specialty applications.  The most common application is compressor filter towers and booster pumps. The SAE Boss fitting is used as a conversion to other adapters.  Another reason it is used is to keep from damaging components that would be normally NPT this way the SAE Boss adapter gets damaged not the expensive filter tower or booster pump head.