Our Experience in Reducing Water Losses by Regulating Pressure in Water Supply Systems

November 2011, Dubai, UAE

Prof. Dr. Dipl.-Eng. Gancho Dimitrov

Head of Department: Water Supply, Sewage and Purification of Water at at the University of Architecture, Civil Engineering and Geodesy, Sofia, Bulgaria

Pressure Reduction

In our experience pressure control in water supply networks is an effective measure for :

• the reduction of water loss and water consumption

• the reduction of the accident rate

• abolition of restrictions on traffic in the streets

• the reduction of operating costs

• the substantial reduction in investment

• the removal of less amounts of water from the water sources

• providing the necessary ecological balance of ecosystems

Types of pressure control, and our research results

• By maintaining constant pressure after the control valve • By maintaining constant pressure after the control valve through water

consumption or for specific periods of time; • Maintaining a minimum pressure through the critical point of the water

supply network.

• individual zones in 45 residences, 120 control valves• reduction of water losses from 15% to 50% of the average water

consumption• success in reducing accidents by 50% to 90%

Case Studies: Pressure Management

DMA 1, 2009

• Total length of water network: 38 127 m

• House connections:1 327

• Number of people: 23 209

• Maximum pressure: 9.1 bar

• Pressure regulator: DN 300

• Output pressure: 5 bar

Fig.1 Change in water consumption at the beginning of the zone

Results

a) period from 12-19 January 2007 before installing the pressure valve;

b) period from 14-22 June after adjusting pressure.

DMA 2, 2007

• Total length of water network: 75 834 m

• House connections: 6 550

• Number of people: 27 400

• Pressure regulator: DN 600

• Outlet pressure by night: 3,5 bar

• Outlet pressure by day: 5,0 bar

Case Studies: Pressure Management

Results

Fig. 2 Change in water consumption at the beginning of the zone for the period from 10-15 August 2007

Fig. 3 Change in water pressure at the beginning of the zone for the period from 10-15 August 2007

Results

Fig. 4 shaft with valves and pressure reducing valve with a diameter of DN 600 with two operation modes (with 5 bar pressure and 3,5 bar)

Effect:

Reduction:

• Water losses by 20%

• Number of accidents by 75%

• Investment recovery period – 1 year

DMA 3, 2010

• Total length of water mains: 104 818 m

• Number of people: 100 000

• Pressure regulators: DN 600 and DN 400

• Input pressure: 4,7 bar

• Output pressure: 3,7 bar

Case Studies: Pressure Management

Results

Fig. 5Installation - Main control valve with DN600 with a bypass line

Effects

Reduction:

• Water loss reduction 1,2 mln m3/ per year

• Number of accidents by 50%

• Investment recovery period - 1 year

CONCLUSIONS

• Pressure control is a relatively efficient way to reduce water losses and

especially the number of accidents.

• Investment recovery period for pressure regulating is very short (from a

few months to 1 year).

• Reduction of water losses by pressure control has a multiplier effect. It

reduces operational costs and investments for new pipelines, pumping

stations, treatment plants, and natural wastewater.

for questions and contact:

Prof. Dr. Dipl.-Eng. Gantcho Dimitrov

E-Mail: info@wato.bg

Mobile: +359 888 305525

Web: www.WATO.bg

Thank you for your attention!