SYSTEMATISK LÄCKSÖKNING / Systematic Leak Detection
The network for distribution of water in Gothenburg amounts to 1,500 km pipes. About 60 % of the length has an average age of 50 years and is made of cast iron, 20 % is ductile iron and has an average age of 10 years. The waterlosses in 1985 were 26 % of the produced water volume. This type of percentage figures is often used to describe the leakage situation of a network. It is more adequate to describe it in terms of leakage per minute and kilometer. The Gothenburg network has a leakage of 22 1/min*km. The aim is to reduce the leakage to 10 1/min* km. This is planned to be carried out by tracking the leaks through measuring the night minimum flow in parts of the network. Thus the low pressure zone for example is divided into 124 districts and the night minimum flow will be measured for each one of them. Each district is divided into smaller parts by shutting valves during the flow measuring. “Complete abstract not presented.”