Meldt
# 1982 York
A method of specifying the HDPE pipes to use in renovation is described. The following factors are considered: flow capacity, stress during insertion into straight and non-straight lines, lifting and buckling forces experienced by the lining while the cavity between it and the old pipe is filled. Four sources of in-servicestress are considered, internal pressure, external hydrostatic pressure caused by groundwater, soil and traffic loads and thermal expansion.In pipes where the cavity is filled, the critical hydrostatic buckling pressure is roughly trebled by the presence of the fill material.