Flooded Underground Chamber 900mm Steel Water Main Cracked Flange Repair

A 900mm steel water main leaking from cracks around a flange in a now-flooded underground chamber thought to be too complex to fix by a Malaysia water company undergoes repair over two days by a determined engineering team and a Sylmasta technician.

Site Underground chamber
Location Malaysia
Pipe Type 900mm steel water main
Repair Type Leak repair
Products Superfast Steel Epoxy Putty

A 900mm steel water main in Malaysia leaking from a cracked flange undergoes repair using Superfast Steel Epoxy Putty

Pipe Defect

Heavy corrosion had caused several large cracks to appear around a stub flange on the 900mm steel water main. The flange meant a clamp could not be fitted and there was no space between the main and the ground to effectively apply pipe repair tape or bandages.

There was no visible means of isolating the main, so flow through the leaking section could not be reduced or turned off. Replacing the damaged section would have meant excavating the chamber and shutting the main off for a prolonged period, something not considered a viable option by the water company.

Repairing the flange had therefore been considered impossible by the water company. It was left to leak unabated, save for a few cursory checks and the pumping out of escaping water when flood levels became too high.

That was until a determined engineering team accompanied by a Sylmasta technician arrived on site and set about finding a way to repair the main or at the very least, cut the amount of water being lost.

The flood chamber prior to water being pumped out for the repair
As water was removed, the scale of the leaks around the flange became apparent


Water was pumped from the flooded chamber so that the pipe could be accessed. An engineer then hammered a series of plastic plugs into the larger, noticeable cracks around the flange.

These plugs reduced the levels of water escaping the pipe, allowing a proper inspection to take place. It was then noticed by the engineer that the pipe did in fact have a stopcock a little further along. They were able to reach it and isolate the leak area.

With water flow now turned off, Superfast Steel Epoxy Putty was used to fill all visible cracks in the main. Numerous 114g Superfast Steel sticks were kneaded by hand and then pushed into holes in the pipe whilst soft.

Within 10 minutes, the putty hardened to seal the crack it had been applied to. Superfast Steel was also used to encompass the flange, permanently fixing in place the plastic plugs which had done such a good job of reducing the amount of lost water.

Because of the diameter of the pipe and the size of the leak area, it took over an hour to apply the necessary Superfast Steel. With flow isolated, it was difficult to see if all cracks in the water main had been found and sealed.

Even after pressure was restored, it was still hard to tell if the repair had been a success. The engineering team decided to return 24 hours later to check the effectiveness.

The inspection the following day revealed a success rate of around 80 percent. All remaining small leak areas missed the previous day were sealed with more Superfast Steel, worked into a sausage shape and pressed along the flange.

This left one large area needing attention, where water was jetting from a gap between flange and pipe. To arrest this, the manager of the engineering team decided to fix a valve in place over the hole using further Superfast Steel.

Any water trying to escape the main would now be channelled towards the valve. Once a tap was fitted and closed, the pipe was completely sealed.

Plastic plugs were hammered into the largest cracks to reduce the amount of water escaping
Superfast Steel Epoxy Putty being hand kneaded prior to application to a cracked flange on a 900mm steel water main in Malaysia
Superfast Steel Epoxy Putty was kneaded by hand and applied to the pipe
Cracks in a flange on a 900mm steel water main in Malaysia undergo repair using Superfast Steel Epoxy Putty
On day two, a valve was fitted using Superfast Steel to funnel water into one area
Completed repair of a 900mm water main leaking from a cracked flange
A tap was then fitted, shutting off the valve to complete the application


Sylmasta would normally recommend reinforcing the epoxy putty with a SylWrap HD Pipe Repair Bandage. The space constraints in the chamber however meant that this was not possible in this application.

Another inspection a day later revealed that the pipe was no longer leaking, denoting a successful repair of the flange. The water company were delighted that an application they had considered unfixable had now been repaired.

Follow Up

This was one of the more challenging Malaysia repairs that Sylmasta were involved in. As a result of this and other live leak repairs made alongside engineering teams, the national supplier approved the SylWrap Pipe Repair Contractor Case for use on Kuala Lumpur’s vast pipe network.

Each Contractor Case contains Superfast Steel, Wrap & Seal Pipe Burst Tape and SylWrap HD Pipe Repair Bandage to make up to six live leak repairs on pipes of all diameters and types, without the need for any formal training.

Maintenance teams are equipped with a Case on their van, enabling them to fix leaks and bursts as soon as they are identified. The Case offers a lightweight, more versatile alternative to carrying around heavy, bulky repair clamps.

Products Used

Superfast Steel
Fast working epoxy putty used to fill holes and cracks, and for high-strength bonding

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