Mufa PEHD Rainplus 40 Rainplus 40 is a PEHD (polyethylene high density) pipe system manufactured by Mufa. It is designed for use in rainwater collection and drainage systems and is available in sizes ranging from 40mm to 200mm. The system is made from high quality PEHD material and provides a reliable, efficient and cost-effective solution for collecting and conveying rainwater. The system is also suitable for use with a variety of fittings, making it ideal for a range of applications.