The Challenge

A live water tank in Gebeng required a new pipe outlet to support increased capacity. However, coring directly through the tank wall posed a serious risk of uncontrolled breach that would lead to water loss and potential supply disruptions to nearby users.

As the tank was in full operation and could not be shut down, careful planning was critical to prevent leakage and ensure continuous service.

Our Approach & Result

To begin, a specially designed steel plate was fabricated to temporarily seal the interior surface of the tank wall, allowing coring to be performed safely from the outside. A certified diver entered the tank to install the plate securely, performing multiple QC checks to ensure a water-tight seal under pressure.

Then, our team proceeded with stitch coring to create the opening. Unlike conventional coring, this method involves coring multiple overlapping holes to form a larger opening, allowing for precise control and preventing the risk of penetrating too deep and damaging the internal plate.

After completing the opening, the new pipe was grouted in place with high-strength material to ensure a firm and sealed fit.

Water tanks rarely allow for structural changes while in use. But that was the challenge we took on at a facility in Gebeng. The client needed a new outlet pipe installed, but couldn’t afford to shut down operations or drain the tank. That meant our work had to be executed with zero water loss and absolute control.

The first step was safety and pressure control. A custom steel plate was installed inside the tank by a diver, acting as a shield to contain internal pressure during coring. Only after a full QC inspection confirmed the plate was leak-proof did we proceed.

To avoid damaging the installed plate, we performed stitch coring by drilling multiple small, controlled holes to form one large opening, stopping just short of full penetration with each core.

Once the opening was completed, the outlet pipe was installed and secured using precision grouting. The result was a safe, clean installation with no disruption to the tank’s operation and no compromise to public supply.

This project shows how careful planning, the right tools, and close coordination can make even the most sensitive jobs possible.