A SylWrap Pipe Repair made to an air conditioning pipe in a London hospital

Hospital Burst 300mm Air Conditioning Water Return Pipe Emergency Repair

A burst 300mm water return pipe forced a London hospital into shutting down their air conditioning system, with a rapid repair essential as temperatures rose to 27ºC on the hottest day of June.

Case Study Overview

Site Hospital
Location London, UK
Pipe Type 300mm air conditioning water return pipe
Pressure 12 bar
Repair Type No pressure pipe repair
Products Superfast Steel Epoxy Putty, Wrap & Seal Pipe Burst Tape, SylWrap HD Pipe Repair Bandage

An air conditioning pipe repair carried out in a London Hospital on a day when temperatures in the capital reached 27ºC

Pipe Defect

The burst occurred on Sunday night through a previous repair effort made to the 300mm water return pipe, located in a restricted cabinet with other service pipes.

Water was escaping at 12 bar pressure and so the hospital had no choice but to shutdown the air conditioning system to prevent the leak causing internal flooding.

Monday was forecast to be the hottest day of June. The hospital therefore needed a rapid leak repair method to minimise the downtime of the system for the safety and comfort of patients, staff, and to prevent machines and equipment from overheating.

The hospital’s maintenance team arrived at Sylmasta HQ first thing Monday morning to collect the products required for a repair. Sylmasta technicians were also able to offer to technical advice based on photographs provided of the burst pipe.

Deep cavities to a 300mm water return pipe in a hospital air conditioning system forced the shutdown of the system until a repair could be made
Deep cavities to the 300mm pipe

SylWrap Solution

Coarse fibreglass strands remained from the previous repair. Once these were cut away, two deep cavities were discovered to be the source of the leak.

The cavities were filled using Superfast Steel Epoxy Putty Stick. Superfast Steel is a fast-working putty kneaded by hand which was mixed and then pushed into the two holes in the pipe. Within 5-10 minutes, the putty began to harden to seal both leaks.

Because of the inconsistent substrates in this case, it was decided to take a ‘belt and braces’ approach to the repair and apply Wrap & Seal Pipe Burst Tape for additional leak sealing security.

Wrap & Seal is a self-amalgamating silicone tape which fuses to form a solid rubber band. Encompassing the entire repair area with multiple Wrap & Seals ensured there was no chance of seepage of water around the epoxy putty.

Once it was established that the burst had been completely sealed, the repair was finished with two SYL866HD SylWrap HD Pipe Repair Bandages applied over the pipe.

SylWrap HD is a composite repair wrap with a water activated resin. It sets rock hard in minutes and provided an impact resistant protective sleeve around the repair for further reinforcement.

Superfast Steel filled the cavities
Wrap & Seal Pipe Burst Tape applied to an air conditioning pipe in a London Hospital as part of a Sylmasta repair
Multiple Wrap & Seal reinforced the repair
The pipe was in a cabinet with restricted space
Completed repair of an air conditioning pipe in a London hospital made using a SylWrap HD Pipe Repair Bandage
Repair completed using SylWrap HD


Throughout Monday morning, numerous alarms had been triggered in the building as equipment began overheating. By Monday afternoon, the repair had been completed and the air conditioning system was back in operation.

Without SylWrap products enabling such a rapid air con pipe repair and the technical assistance provided by Sylmasta, the hospital could have gone days without any air conditioning – a clearly unsustainable situation when temperatures in London were peaking at 27ºC.

Follow Up

The hospital and the maintenance team who carried out the repair were pleased with the speed and ease with which the application had been completed.

With many hospitals across the United Kingdom featuring older pipework systems prone to leaks and bursts, SylWrap Pipe Repair solutions can provide permanent repairs which offer a cost effective alternative to replacement.

Products Used

Superfast Steel
Fast working epoxy putty used to fill in holes and cracks on pipework

Wrap & Seal Pipe Burst Tape
Self-fusing silicone repair tape which creates a solid rubber band over leak areas

SylWrap HD Bandage
Water-activated wrap sets rock hard to reinforce, protect and strengthen repairs

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