The Emergency

National Gas Services were informed of a high-volume gas escape on the distribution network, caused by the failure of a section of 10” cast iron (CI) pipe at medium pressure (MP). Additional concern was raised because it was bonfire night, meaning there were many potential sources of ignition.   

The Solution

The original plan was to carry out two 315mm squeeze-offs on polyethylene (PE) pipe at either end of the cast-iron section. However, due to delays in locating the valves and PE pipe sections, the customer decided to opt for a single 10” stopple and valve closure on the cast-iron section.  

Our engineers promptly fitted a supa tee and valve, dropped the stopple, and had the gas estate under control by 18:00. Although the main had a running pressure of 2 bar, the pressure was found to be 200 bar due to the volume of gas escaping. It was estimated that 10,000 cubic metres of gas were being lost per hour. Our team monitored the stopple overnight, while the customer carried out the necessary repairs.