Hikelok often hear that the twin ferrule tube fittings and valves are not easy to use, unreliable, and leak after installation testing. No matter how hard the nut is tightened, it is useless.

The ferrule must also work equally well across the tubing diameter tolerance range, typically ±0.005 in., and handle surface defects such as scratches that may be several thousandths of an inch deep.

Sometimes called an EO style fitting, the design incorporates a 24° tapered throat on the fitting body, and a nut that drives a ferrule into the tube as it is tightened.

Product Features. Suitable for the outer diameter of the pipe:1/4" 3/8" 1/2" Product Material: Brass. Used with plastic and copper tubing. Package Include:120PCS Compression Sleeve Ferrules.

For sizes greater than 1/4 in. (6 mm) to grip, the back ferrule bites into the tube. To do this effectively, the ferrule must be harder than the tubing material, which is typically 316 stainless ...