A modernisation and extension of a water- and wastewater network in Romania reduced leakage with more than 10 %. This resulted in big savings on operational costs for a large water supply company covering a water network of about 400 km and a population of approximately 200,000 people.
Major leakage reduction
The Romanian water supply company experienced a leakage reduction of 10 % when changing the pipes and installing AVK valves.
Also, a directly buried solution was selected and made the argument for using high quality products. At first, the water supply company used PVC pipes and T-keys for valve operation. These pipes, once clogged with soil and asphalt, made it impossible to operate the valves and led to a quick decision of including extension spindles.
From metal seated valves to AVK resilient seated gate valves
Today, many Romanian supply companies use gate valves, extension spindles and air valves from AVK. However, up until year 2000 only metal seated gate valves were used which caused some problems in relation to shut off tightness and different kinds of stem defects, such as wedge nut threads problems, breakage of the stem sealing area as well as breakage of the stem, caused when the valves were forced into closed position. Butterfly valves were used in the beginning of this modernisation, but because the water company were afraid that butterfly valves could cause water hammer and previous butterfly valves had sealing problems, it was decided to use only AVK gate valves, especially for the main lines.
Directly buried gate valves are still used for installations up to DN 200, whereas valves larger than DN 250 now are mounted in manholes.
The water supply company also used AVK air valves, which also had a positive impact on their network. Some of the main advantages expressed by the water supply network are reduction of the hydraulic problems in the network as well as easy installation and non-corrosive material. Furthermore they were very positive to discover, that there were no water losses during the operation.
A satisfied customer
The water supply company is very satisfied with their modernised network. They have experienced the following benefits:
- The tightness of the valves in closed position (this was very problematic on the metal seated gate valves)
- The possibility to shut off the water in small areas when necessary (this was impossible or quite difficult before)
- An optimum delimitation of distribution areas
- The easy access to valves regardless of the condition of the streets using extension spindles
- Lowering the installation costs by eliminating some manholes
- Fast and secure handling of hydrants