Viega PureFlow PEX pipe and fittings have been listed by UL as approved for use in exposed fire sprinkler systems in basements. The UL listings mean builders and contractors now are able to use PureFlow, Viega’s versatile system of PEX pipe and fittings, throughout an entire residential fire sprinkler system, Product Manager Seth Larson notes. The listing eliminates the need for contractors who have used PureFlow PEX throughout a house to have to join it to pipe of another material in the basement, the company points out. The system has an easy alignment bracket that eliminates the need for measuring when hanging pendants. Viega.