In both hot and cold systems, compression fittings are utilised to connect copper and plastic pipes. They are perfect for industrial applications because of their excellent endurance to vacuum conditions and pressure vibration and WRAS approval. They may also be used for household tasks. Compression plumbing fittings are made up of an outer compression nut and an interior "olive" or compression ring. The area between the nut and the pipe is sealed for a watertight connection when the nut is tightened.