What is a “flexible” pipe and how are they designed?
PVC-U piping systems belong to the category of so called “flexible pipes”. This flexibility provides a great advantage compared to the more “rigid pipes” made of traditional materials such as concrete or clay: For flexible pipes: the soil supports all the stresses on the pipe (including soil weight) and the pipes deform slightly but do not break For rigid pipes: the soil concentrates the stresses directly on to the crown of the pipe, these pipes do not deform but a failure mode results in a break in the pipe.
