Creep Resistance of PE-X

All thermoplastics essentially act like elastic when stressed for a short period of time and will return to their pre-stressed state when the stress is removed. However, when stressed continually over a long period, they will “creep”, as the deflection of the material will increase with time.

The amount of “creep” that any plastic part experiences is influenced by several factors – the material from which it is made, the stress under which it is used, and the temperature at which it is exposed to the stress.

Because all plumbing systems (hot water plumbing systems in particular) are subject to continuous hoop stress from the pressure of the water within the pipes and to elevated temperatures from the transport of hot water, the creep resistance of the materials used within these systems is of vital importance.

Below is a comparison of cross-linked Polyethylene (PE-X) compared to some other polyolefins: