Download a .pdf Permaflow brochure Here << Permaflow culverts are an exciting new range of heavy duty plastic culverts with sizes up to a massive 1500mm diameter. All Permaflow culverts are 6 meters in length, they are 100% polyethalene, smooth bore for increased flow rate, externally ribbed for strength, unique lifting eyes for safe installation, rust … Continue reading Permaflow culverts