Esholt STW, Thermal Hydrolysis Plant

Annular gap between flanged pipe and sewer tank access hole.

Provide a permanent seal within the annular gap whilst also providing structural support for the stainless steel pipe.

Flexseal Ring Seal, providing retro-fit solution for permanently sealing the flange pipe into the tank.

Yorkshire Water contracted the build of a Thermal Hydrolysis Plant in Esholt, Bradford to support its northern operations and supply ‘green energy’, contributing to attaining its carbon footprint reduction targets.

Contractors were required to build a sewer storage tank on the site with a 1200mm access door.

The door was constructed from a wooden frame with concrete poured around it and the frame removed once set; leaving and annular gap for a 1200mm flanged pipe to be installed, which would form the access door.

Next, the pipe needed attaching to the tank, provide a watertight seal and be centralised within the hole.

This was achieved by using a Flexseal Ring Seal to fill the void between the outside of the pipe and the internal surface or the tank’s hole.

The Ring Seal is made up of small individual links that when all linked together, create a circular seal. Each link is made from an EPDM moulded rubber, stainless steel squeezing plates housed in plastic casings, held together with high strength bolts. When the bolts are tightened the rubber expands outward uniformly, creating a pressurised seal.

Flexseal provided the seal made to order, ensuring installation was as quick and efficient as possible. The contractors had no experience in fitting with Ring Seal’s, however, installation was complete in less than 1 hour.

Added: March 2019 | CSR025