Polypipe's Effast PVCu pipes employed in Flexigester Integrated Faecal Treatment system for Namisu Children's Village waste treatment project in Malawi. Projects. Sep 29, 2014. Connecting up the gas pipework … Used worldwide for plumbing systems as well as for the supply of potable water, Effast also features an incredibly smooth bore providing good flow characteristics, as well as abrasion resistance. Les James of Polypipe commented: “It has been very rewarding to contribute …