When undertaking tunnelling works, one of the biggest challenges to overcome is working in high water tables or water-saturated formations.

With this in mind, UDS International has designed an effective Non-Return Valve solution to enable injecting fluids into the annular space during tunnelling operations.

UDS’ Non-Return Valves allow tunnelling operators to remove all injecting connections for lubrication and grouting. This reduces the risk of blow-outs or flow-back tunnel fluids after the work is completed, and during maintenance works.

The valves are made from plastic and can be used for tunnelling projects with high annular pressure or standard operation.

UDS offers two designs of Non-Return Valves to meet different flow requirements and back pressure:
– The Piston model has pressure retention up to 24bar and is
   safe up to 140m depth
– The Butterfly model has pressure retention up to 8bar and
   is safe up to 60m depth.

Non-Return Valve key features
– Reduces the risk of blow-outs and flowback tunnel fluids
– Two designs to meet different flow requirements and back
   pressure