Brass compression fittings connect with pipe to transport air, drinking water, flammable gases, slurries, and chemicals in residential and industrial plumbing applications. Compression pipe fittings temporarily repair two new or existing pipelines, and include an outer compression nut and an inner compression ring or ferrule (sometimes called an olive), usually made from brass or copper. Ferrules vary in shape, but most commonly are the shape of a ring with beveled edges. Brass, an alloy of copper and zinc, is strong, highly conductive, maintains machineability at high temperatures, and resists corrosion from water, heat, acids, minerals, and peaty soils. Brass, a bright gold color, is compatible with stainless steel, copper, or zinc piping.