Horiznext Stainless Steel Compression Tube Fitting, Union, 3/8" Tube OD Straight Adapter

The coupler helped connect lines without any leaks. I highly recommend this part.

Please disregard the negative reviews regarding this item not fitting or threads being wrong. Those reviews were left by people that do not understand what this fitting is for. This is a union fitting to allow you to connect to a 5/16 outer diameter (0.3125" or 8mm) metal tube. You slide the nut onto the tube. Then you slide the smaller ferrule onto the tube. Then you slide the bigger, cone-shaped ferrule onto the tube. Then you push the tube into the fitting. Then you slide the nut down the tube and begin tightening it onto the fitting. The tightening process will wedge the ferrules together - and crimp them like crazy onto the tube. You can then assemble or disassemble the joint as often as you like. Be aware the ferrules will be permanently crimped onto the tube - and the nut won't be able to be removed from the tube. Do not use on plastic or teflon tubing. This is for steel/stainless/aluminum tubing only. I suppose it would probably work on copper, but these fittings rely on your tubing being nice and round - and stiff enough to take the crimping process. They work great and can handle tens of thousands of psi of pressure.

Bought this to replace a push in type fitting to my water softener salt tank. Does not do well on plastic tubing. It leaked from all sides. The description does not specify if this can be used on plastic tube. Might be fine for hard lines. Also the fitting had an extra piece that goes between the compression ring and the end cap. After trying to tighten the fitting to stop the leaks I found this extra ring was deformed and there was no way to straighten it so it could be used again.

ok

s/s product used on hydralic pressure lines on equip.