Sewer bends in Washington D.C. Do you have bends in your Washington D.C. sewer pipes? The Perma-Lateral material has a flexible PVC coating that allows the liner to invert through and negotiate 22, 45, and sweeping 90 degree bends with ease. Renew your Washington D.C. sewer pipes today with a minimum life span of 50 years per ASTM F1216 third party testing.