For people not in-the-know, a JIC fitting is a screw-type fitting with a flared and smooth butt-end. It is kind of a strange sort of fitting, only commonly used in either plumbing or industrial settings. Such JIC fittings seem strange until you consider their particular purposes.
Imagine you have a pipe and you want a liquid to pass through the pipe with as little leakage as possible. You would use a JIC fitting because the fitting helps funnel the liquid past the joint, where it is most likely to lose a few drops of fluid. The flared end of the fitting acts as a sort of mini-funnel, allowing the fluid to pass through the opening in the end of the fitting without losing any fluid.
Extra Secure Fitting
Besides funneling, JIC fittings serve as an extra secure fitting. The flared end drops into an open chamber end in the next piece of pipe. Because the fitting is screwed all the way in, and the flared end fits into the other pipe, the fit is very tight. It would take a very strong person to pull it apart or damage it. The very secure fit ensures that the force behind or in front of the JIC fitting cannot separate the two pipes.
Take Pressure Measurements
A JIC fitting not only allows fluid to flow through its flared end, but it also allows smaller diagnostic tools to slide through this portal to test the pressure and take measurements of the pressure. There would be no way you could do this if you just screwed pipe end to pipe end because you could not guide the tools through and keep them safe in the process. Just as easily as you can guide diagnostic tools in, you can pull them out again.
Think You Need JIC Fittings?
Now that you know what JIC fittings are and what purposes they serve, you can use them for your own industrial or plumbing needs. You can order them from most industrial supply companies, and the fittings come in a variety of flared-end diameters. Price is based on size and the number of fittings you need. If you are not sure, describe the diameter of the pipes you are attempting to fit with a JIC fitting and what you are attempting to do to the sales representative. He or she will be able to point you in the right direction.