PVC pipes are flexible pipes, they can flex without breaking when loaded externally from soil weight and heavy duty traffic. Rigid pipes, such as those made of concrete, clay or ceramic are unable to flex when loaded and will experience wall crushing and collapse when their load limit is reached. This is generally referred to as “crush strength” and “D-Load”, however since flexible conduit reacts differently under a heavy weight load, these terms do not apply to PVC pipe.
When a PVC pipe encounters external loading, its diameter will begin to deflect. If the pipe is buried in the right supportive soil conditions, the stiffness of the soil combined with the pipe stiffness will resist the deflection.
By combining the proper soil stiffness and pipe stiffness, PVC pipe of all sizes can be used at significant depths, very efficiently and economically by using proper installation technique.
PVC pipes typically will deflect up to 4% depending on the soil type and conditions. This does not present a problem with regards to the integrity of the pipeline.
Therefore PVC pipes can successfully be used where the surface will be subject to external loading such as road traffic*
- PVC pipes will not buckle even in deflection sup to 10%
- Apart from being better than concrete as far as water quality is concerned, their embodied energy and Carbon footprint is significantly lower than concrete
- PVC stormwater pipes are available in diameters up to 375mm and stiffness up to SN8
New report available from Uni-Bell's Technical Directory, John Houle on PVC Pipe standing up to Large Earth Loads
* Provided that they have been installed as per industry standards and guidelines