Common Pipe Failures

Below are the most common causes for PVC pipe failures. PVC failures are not limited to these particular problems.

 

IMPROPER INSTALLATION

PVC installation requires attention to detail and sufficient time for the joints to solidify. A rushed installation is a common issue in PVC-related incidents.

DEFECTIVE Manufacturing

PVC manufacturing requires precise chemical processes that take place at multiple required temperatures.  A failure to adhere to these practices can result in defective PVC pipes.

 

Solvent Cemented Joint Issues

Many people believe that PVC pipe is very forgiving and anyone can install the pipe. This is true as long as long as the rules are followed. The rules are that the pipe end must be square-cut, deburred, and chamfered. Two heavy coats of cement are to be applied to the end of the pipe and one light coat to the inside of the socket. The pipe must then be fully inserted all the way to the bottom of the socket and then held in place for at least 30 seconds until the cement sets up sufficiently to hold the pipe in place, otherwise the pipe will back itself out of the tapered socket.

A common issue with PVC installation arises when a job is completed in a rushed manner, often in large-scale development with tight timelines.  These hasty installations can lead to serious consequences for property owners.

 The pipe shown above was short inserted into both elbow joints and there were areas of the joint where there was little or no bonding between the pipe and the fitting socket.

The pipe shown above was short inserted into both elbow joints and there were areas of the joint where there was little or no bonding between the pipe and the fitting socket.

A small margin for error in the manufacturing process

PVC pipes are manufactured by melting and extrusion of PVC powder. This chemical process, like most chemical processes, is vulnerable at many points along the timeline of manufacturing.  If the extrusion process is not operated at the proper temperature the pipe is weak and can become brittle.

A weak and brittle pipe is not immediately noticeable, and can be installed under the assumption it can handle the load of a healthy pipe.  However, a weak pipe put under high residual stress will begin to rupture over time and can cause catastrophic damage once a full rupture takes place.

 The image above shows how high residual stress on a weak pipe can cause what is referred to as a creep rupture.

The image above shows how high residual stress on a weak pipe can cause what is referred to as a creep rupture.