Chemical Degradation

Chemical Degradation of High-Density Polyethylene

High-density polyethylene sulfuric acid storage tank.

High-density polyethylene.

The plastic sulfuric acid storage tank had been in service for approximately 15 years. An inspection of the tank was performed to determine if it was still suitable for service.

Service Life
Approximately 15 years.

Examination of the interior of the tank revealed a surface riddled with surface cracking caused by chemical attack of the sulfuric acid on the HDPE. A cross-section of the tank wall revealed the presence of micro-cracking. Based on the condition of the tank, it was deemed unfit for further service. It was also recommended that the tank be replaced immediately.