ForgeFix Pipe Clip Single Cliplock - ForgeFix PCSC28, These Forgefix Single Cliplock Pipe Clips are made from heat resistant polypropylene, designed to withstand the temperature changes in central heating systems, and are effective with temperatures of up to 100°C (most pipes in domestic central heating systems operate at around 70°C). Used when fitting most types of pipe work. Polypropylene, also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. An addition polymer made from the monomer propylene, it is rugged and unusually resistant to many chemical solvents, bases and acids. ForgeFix PCSC28 Pipe Clip Single Cliplock 28mm Box 100