Water is a scarce resource that we need to protect. We need to secure water for the next generations and a growing population. Control valves are regulating valves. They maintain certain pressure, flow or level regardless of changes in the supply network, and therefore help reduce water losses and contribute to efficient water supply. AVK supplies a complete range of control valve solutions for water utilities. Control valve solutions can reduce energy consumption for pumping by allowing for a lower pressure in general and especially during off-peak hours
Consequences of water loss
For water utilities, 'non-revenue water' is water that has been produced but “lost” before it reaches the customer because of leaks, theft or metering inaccuracies and is a source of unwanted cost. From an environmental perspective, the significant amounts of precious water that are lost, and the energy used to treat and distribute the water lost is also wasted.
So how can control valves help?
Automatic control valves are used to obtain efficient flow management and pressure resulting in reduced:
- water loss through leakages
- risk of water hammer and pipe bursts
- disruption to consumer
- Minimized risk of contamination
increased savings for water companies
Main Features - AVK control valves
The safe choice, offering accurate regulation, easy maintenance as well as long durability:
- All non-coated metal parts of stainless steel AISI 316 as standard.
- Fusion bonded epoxy coating (300 micron) - GSK approved.
- AVK's own, drinking water approved, rubber compounds
- Modular pilot system to enable easy fitting to other applications without replacing the valve.
- Independent adjustment of the opening and closing speed for full control.
- Parabolic plug design to provide precise regulation and stability at low flow.
- Large diaphragm to secure fast reaction to minor changes in pressure.
- Lifted seat to prevent damage caused by cavitation inside the valve body.
- AVK design, manufacture and 100% pressure test
Pressure Control - reduce or sustain:-
1- Pressure reducing control valves.
A pressure reducing control valve will automatically reduce a higher inlet pressure to a lower outlet pressure - regardless of changes in flow rate or inlet pressure.
The pressure reducing pilot senses the outlet pressure through the connection on the valve outlet port. Under flowing conditions the pressure reducing pilot reacts to small changes in the outlet pressure and controls the valve position by modulating the pressure in the control chamber. When the outlet pressure changes according to the set-value of the pilot, the pilot modulates and ensures pressure control.
Example: The pressure is 7-8 bar, appropriate to supply the consumers in area A but too high for the consumers in area B. Solution - a pressure reducing control valve is installed to reduce the pressure to 3 bar in area B.
2- Pressure sustaining/relief control valve.
A pressure sustaining control valve automatically maintains a minimum pre-set inlet pressure by relieving excess pressure regardless of changes in flow rate.
The pressure sustaining pilot reacts to small changes in the inlet pressure, controlling the valve position. Should the inlet pressure falls below the set point the main valve closes or modulates to ensure a minimum inlet pressure. The sustaining valve will hold a minimum back pressure on the inlet and normally allows flow. The relief valve normally remains closed only opening when pressure exceeds a pre-determined set point.
Example: When the water reservoir fills the pressure drops leaving the consumers without water. Solution - a pressure sustaining control valve is installed to maintain the pressure for the consumers.
VARIANTS AND CONFIGURATIONSPressure reducing and pressure sustaining/ relief valves are part of our standard range. On request, we also offer control valve variants such as:
Surge anticipation valve: Automatically protects the pipe system against pressure surges, mainly happening at pump start-up, or in the event of failure. Altitude valve: Automatically controls the water levels in tanks or reservoirs.
One-way: The altitude pilot senses the water level and opens to refill, once the level drops below set point. Two-way: Like one-way, but furthermore, the valve opens for returning the flow in case the inlet pressure is lower than the tank/reservoir pressure.
Float level valve: Automatically controls the water levels in tanks or reservoirs.
Modulating: The modulating float is remotely installed and controls the tank/reservoir level at a defined set point. The valve closes tightly at desired level and opens, if filling is needed.
Non-modulating: The non-modulating float keeps the valve closed until the tank/reservoir level reaches the minimum acceptable set point. Then the control valve opens fully to refill, until it reaches the maximum acceptable set point, and the valve closes.
Constant flow valve: Automatically maintains the flow demand, regardless of changes in inlet or outlet pressures. Solenoid control valve: Automatically either closes or opens the main valve. Dual solenoid control valve: Automatically controlled by electrical signals. The control valve offers full regulation of pressure, flow and level. Multi-function and solenoid override Multi-function control valves, such as a combined pressure reducing and pressure sustaining control valve, are also part of the range. Furthermore, many of the variants are available with solenoid override, where an electric signal either closes or opens the main valve. Optional configurationsAVK also offers accessories such as pressure gauges and position indicators as well as special configurations e.g. with built-in anti- cavitation trim, lifting lugs and flush valve on the filter.
What does AVK offer ?
Pressure control valves
- Pressure reducing (standard)
- Pressure reducing with check valve
- Pressure reducing with isolating pilot
- Pressure sustaining/relief (standard)
- Surge anticipation
Level control valves
• One-way altitude
• Two-way altitude
• Float level (modulating)
• Float level (non-modulating)
Flow control valves
• Constant flow
Electronic control valves
- Solenoid control, open/close
- Dual solenoid control, regulating
- Dual solenoid control, regulating
- Multi-function control valves
- Pressure reducing / pressure sustaining
- Float level (mod.) / pressure sustaining
- Float level (non-mod.) / pressure sustaining
- One-way altitude / pressure sustaining
- Pressure reducing / constant flow