Case Study Overview

During an overhaul of this Yorkshire sewer, workers unblocked siphons by removing an existing walkway and other steelwork and installing a new, smaller walkway to prevent further obstructions. Due to the noxious and explosive sewer gases, a ventilation system was required to protect workers.


The ventilation system had to allow for the impact of changing weather conditions and different rates of sewage flow. There was also the danger of the fresh air being supplied too forcefully; pockets of gas could be disturbed and cause explosions.


RVT installed a powerful centrifugal fan that delivered fresh air at a safe pressure to displace the sewer’s contaminated air. The Ventex CF 450S (Centrifugal Fan) generates airflow of 20,500m/hr so was ideal to supply fresh air throughout the entire sewer tunnel. Gas levels were also continuously monitored throughout the project.



Products Used