Zoom: Equipment for Water Supply and Wastewater Treatment

AVK Group’s solutions are currently used in the entire water process or water cycle, from pumping to treatment, including the transfer, distribution, and treatment of wastewater. The equipment manufactured and marketed falls within the range of gate valves (up to 2500 diameter), butterfly valves (up to 3600 diameter) and regulation or smart valves, which allow to stabilize a pressure or flow rate according to the consumption of subscribers. Those valves allow to follow the daily flow rate and the night flow rate, so as not to remain on a pressure downstream of 4 to 5 bars over all the year whereas the drawing is with high consumption. Connection valves with flap systems are also available, and the company has one of the widest ranges of drinking water valves and pipe accessories available today; However, pumps are not manufactured.

When the diameter increases, it is better to use butterfly valve for a better management of clutter and manhole. There is a range of materials suitable for aggressive liquids or wastewater. Wall and knife gate valves are used for wastewater treatment plants. The range of fire protection valves should be placed on fire hydrants in cities to ensure the safety of inhabitants.

The gate valve is the most used in water networks in Africa; Although quite underestimated because it is under the ground and the device is not often seen, this valve is used to sectorize a network as part of the procedure to determine the Non-Revenue Water (NRW). If the valve is not watertight, the whole calculation logic is wrong. Hence the problem of quality of the products set on the networks, because very often the valves don’t operate and are not watertight.

The software AVK Assist can be installed on I-pod or Android to read data of connected valves which have a barcode; through that means, it is possible to geolocate the position of the valve. There are also data sheets and small software programs to calculate flow rates. Smart valve includes a sensor system, which gives to the operator, instant information on the handling of the valve, which can no longer be handled without the operators’ knowledge. Similarly, that technology allows to notify the handling of the fire hydrant by an unauthorized person. That new technique is very useful to fight against the phenomenon of Non-Revenue Water, i.e., water produced but not billed to the customer.

AVK demands the same requirements on water cycle as it does on gas management. There is a completely crimped operating nut encompassing the cast iron cover and fully vulcanized. There is no movement or vibration between the nut and the gate, therefore no corrosion. There is a concept where the nut is simply positioned, and continuous movement can be noted. Also, after few months or few years, there is a phenomenon of vibration and then corrosion.

AVK is one of the only utilities that manufactures rubber (polymer) used in its equipment. A gate valve is made of EPDM which compatible with drinking water. This means that AVK has a quality control on the manufacturing process, which considers the European standard EN 681 on the elasticity of the rubber and the remanence (capacity to be crushed when the valve is closed and to recover its initial shape when the valve is opened). German GSK certification allows AVK to guarantee the quality of Epoxy coating on the valve. There are several criteria for non-destructive control that guarantee the longevity of Epoxy coating on the equipment, which prevents the valve from corroding even after ten (10) years of use. As guarantor of quality of their networks, water utilities would benefit from taking those certifications into account.

The concept of flanged valves can be multiplied into different connection types. Although the gate valve is the new product launched, there are several PEHD pipes in the sub-region. It is a very sleeved equipment with no bolts to tighten and no torques to comply with; it is enough to weld the PEHD pipes on the end caps which are already crimped and tested in the factory. The advantage of PEHD is the guarantee of no leakage, as the polymer can be welded.

Keyhole goes together with valves, as they constitute the access point to the valve, through which it is possible to search for leaks thanks to data loggers, among other quality systems, which allow to listen the return of network. After the theft of cast iron and at the request of customers, AVK has turned to composite materials, which are recyclable, cost effective, non-corrosive, cannot be stolen and consume less energy to meet today’s energy requirements. A new cast-iron keyhole, all-composite (round head, hexagonal marking, dedicated colour, numbering, etc.) that can be raised to fit under the roadway as vehicles pass by, was launched. In fact, one of the recurring problems is the crushing of the roadway by heavy vehicles, which leaves the keyhole protruding; it therefore remains at a height above the roadway. The solution at hand will follow the movement of the roadway and ensure a constant continuity between the head of the keyhole and the road, which will facilitate the handling of valve over years ahead in the interest of sustainability. At the request of customers, it is being developed and sold in Africa.

The origin of NRW can be the leaks in the valves. Then, pipe repair equipment is of major importance. Those are solutions or sleeves for all pressures, all materials (PVC pipe, PHP, steel, etc.) and all types of pressure (up to PN=40) that allow the repair of pipes or conduits in charge without cutting off the water supply. Information on the type of pipe, the external diameter and the pressure allow to manufacture dedicated sleeves to solve quickly and at low costs the leakage problems, thus avoiding untimely water cuts.

The connection of two (02) PVC or cast-iron pipes with leaks can also be repaired. The advantages include the simplicity of the repair which is definitive and guarantees the watertightness on long term, without cutting the pipe or excavating the conduit, and without interrupting the water supply so as not to disturb the supply to final users during the process.