Walker Construction (working with Thames Water)

Ashford Designer Outlet

Exposed smaller surface water pipe than initially expected causing connection issues

Provide a reliable solution for connecting 375mm concrete pipe to 675mm concrete pipe. The connection must be fit for purpose and not be labour intensive.

Flexseal’s modular Ring Seal was used to provide a secure connection within the annular gap of the two pipes.

Surface water was being conveyed away from the complex via what was thought to be 450mm concrete pipe. The main drainage pipes used for the site were 675mm concrete, meaning Standard Couplings used with bushes would provide a suitable connection.

However, upon exposing the surface water pipes, the contractors revealed a much smaller 375mm concrete pipe. This would mean that a connection using a Standard Coupling would require over the recommended number of bushes and subsequently a concrete collar would need to be cast – a bodge job which would be time consuming, costly and labour intensive.

After hearing about the problem, one of Flexseal’s experts for the area visited the site to assess the situation. He instantly knew that a traditional coupling method would be tricky, however, he did have a solution.

Flexseal specified a modular Ring Seal, an easy to install seal that is designed to fill annular gaps. The Ring Seal would need to be installed on the outside diameter of the smaller pipe to the inside diameter of the larger pipe and thus providing a water tight seal within the annular gap.

As well as providing a water tight seal, the product creates a strong grip and after the contractors installed the product, this was tested with a pressure test, which it subsequently passed.

The main benefit of the product was the time it saved in resolving the problem. It took the installers only 10 minutes to make the connection, compared with hours using a bodge it method.

The whole solution from Flexseal hearing about the problem, to making the connection was dealt within a matter of days.

Added: May 2018 | CSR011