Polybutylene PB Hot Water Pipe Failure

The polybutylene PB pipes and pipework are used in domestic, commercial and industrial properties for heating, domestic hot water supply DHWS and cold water systems. It is often thought that corrosion does not affect plastic pipes. However, PB pipes have a history of failures or leaks especially on the DHWS systems.

The life expectancy of PB pipes is around 50 years but often these pipes fail 10-20 years into their service. Plastic pipes degrade from the inside under the influence of water, chlorine and dissolved metals eventually causing pinholing and leaks. On the outside PB pipes degrade with exposure to UV light, oxygen and other metals.

The root cause of the failures are often associated with plumbing design and corrosion elsewhere in the system, water temperature and quality and correct material or grade selection.

At LPD Lab Services, failed pipes are investigated from the outside and from the inside using optical microscopy and appropriate chemical analysis to identify the presence aggressive species like SEM/EDX, XPS and IC. The degradation of the PB polymer can also be assessed using FTIR.