View Tameson's range of compression fittings. Compression fittings are typically used for gas or water applications and can securely connect pipes together without soldering. They have an outer and inner compression. To install, slide the nut over the end of the pipe and then slide the ring over the end. Insert the pipe into the compression fitting and tighten the nut firmly with two wrenches. However, be careful not to over tighten. These fittings should not be re-used, because the inner compression ring deforms during compression. It is important to know your media to properly select the right material. Common materials are brass, stainless steel, and zinc-plated steel. They have either 2, 3 or 4 connection points.