How VIDI is Helping to Address Network Challenges.
For a water network to be managed effectively it is vital to know whether a valve is open, closed or at some intermediate position. The VIDI positioner is a small intelligent device that sits between the top of the AVK gate valve (often known as a sluice valve) stem and the valve cap. The VIDI positioner automatically communicates the position of the valve back to the network management team. Alarms can also be set up to alert when the valve position changes.
The VIDI positioner can be supplied as an integral part of a new AVK Smart gate valve or retrofitted to legacy AVK gate valves. Retrofitting is straightforward; the stem cap is removed, the VIDI positioner installed, and the stem cap replaced. It really is as simple as that!
This case study looks at examples of how the VIDI positioner is being used by water companies in the UK and Ireland to address network management challenges.
District Metered Areas (DMA) Wrexham in North Wales is relatively unique in that its water needs are served by a ring main that runs around the town. Within the ring main, however, network management follows the accepted approach of dividing the supply network into a series of DMAs.
A DMA is defined as a discrete part of a water distribution network. At the interface between adjacent DMAs it is common to find boundary gate valves. These valves are typically closed but may be opened on occasions for strategic reasons, often to assist the resilience of the network.
An unauthorised opening of a boundary valve can cause major problems with water quality and pressure stability. Often zones are fed from a different source which can be dynamically different. If water from a high pressure zone enters a lower pressure zone the flows will reverse. Which in turn disturbs sediment causing discolouration; the high pressure can also lead to breakages of pipework used to the normally lower pressure, therefore it is critical valves are not opened without prior planning. VIDI positioners and smart gate valves offer real-time information prior to any activity so informed decisions can be made remotely and recorded automatically, saving time and resource. Boundary valves are critical assets. Leaving a boundary valve open can lead to false leakage alarms. Furthermore, an open boundary valve significantly compromises efforts to locate potential leaks in a DMA using step testing.
Typically, locating and closing off an open boundary valve requires a team to be mobilised. It is often challenging to locate the guilty valve and it can become an expensive, time-consuming and
disruptive task.With a VIDI positioner, the network management team know whether a gate valve is open, closed or at some intermediate position in between. The VIDI positioner communicates the
position of the valve using LoRaWAN or NB-IoT technology.
LoRaWAN is a low power, wide area radio network that connects battery-operated devices to the internet. The low power and low bit rate of the LoRaWAN approach means battery life can reach up to ten years and beyond. It is particularly effective for demanding communication scenarios including remote rural locations.
NarrowBand Internet of Things (NB-IoT) is an increasingly common low power, wide area technology. NB-IoT networks are growing across the UK and offer a real shift in the way UK water
companies can now obtain regular data with increased granularity over legacy systems.
Real Time Alerts. AVK Assist is AVK’s free mobile app. Initially developed to help network engineers specify, select and record the location and details of valves and hydrants, AVK Assist has been
extended to provide an interface with VIDI devices. This means that an engineer can now track and manage his network assets via his mobile device. This includes receiving instant alarm alerts when the position of a valve is changed.
VIDI positioners quickly pay back their initial investment. For example, in the case of the Wrexham DMAs application the figures are as follows:
An engineer is costed at £49.56 per hour, and HD Water estimate they can easily spend three or four days a month re-zoning and operating strategic valves, particularly during cold winter months and peak summer months to ensure resilience, as well as carrying out essential planned works. In Wrexham alone the positioners are paying for themselves by saving around £1,500 per month by reducing verification works and operational reporting as everything is documented in real-time and reports can be generated at the click of a few buttons.
Exceptional Operational Efficiencies
In regional coverage black spots HD Water spend two days per week manually downloading devices, this comes at a cost of £792.96 per week, plus the added negative impacts of carbon footprint,
potential Health and Safety risks as assets are often in roads, chambers and hard to reach places like trackways and woodlands. Having a LoRaWAN system has proved a real game changer and
offers considerable benefits with operational efficiencies.
Mark Jervis, Leakage Manager at HD Water, said:
“The removal of the need to manually check valves and other assets has allowed us to be much more proactive with other resources extending more time on other priorities, such as leak detection and customer service.”
Working Smarter not Harder with AVK Smart Fire Hydrants Glyn Ceiriog is a small and relatively remote village north-west of Oswestry. AVK throughbore fire hydrants have been installed. The hydrants are equipped with VIDI positioners. If water levels are low, water is tankered into the area and fed into the pipe via the hydrants. The VIDI positioners will capture these events and log
activity so “to join the dots” when events occur that need reporting. The fact that this is now automatically recorded means that significant time is saved in the reporting of events. The VIDI positioner is used for a range of purposes. When the pipe is periodically flushed, the VIDI positioner advises how long the hydrant has been open. This is very important when logging flushing schedules and ensuring correct procedures have been carried out. Again, all the information is automatically recorded via the VIDI positioner meaning flushing programs can be verified and results managed much easier.
HD Water carry out a heavy flushing program in Wrexham annually with 32 DMAs being flushed by two engineers during the night. The benefit of automatic data recording saves a great deal of additional works during these testing night periods. Again, at £49.56 per hour it only needs a few hours paperwork reduction and the VIDI positioner pays for itself in one flushing program. There are also considerable advantages to seeing any correlation between flushing activity and discolouration complaints; or water quality improvements; or network efficiency improvements. Using other VIDI smart IoT devices you can easily capture the entire network picture and gain a great deal from the data. Discoloration of water is a major customer service issue for water companies. Discoloration can often be linked back to hydrant use which agitates settlement in the pipes. The VIDI positioner provides a record of when each hydrant (and gate valve) has been opened and this can help identify a potential source of discoloration or, alternatively, rule it out.
Clamping down on water theft remains a challenge in many parts of the UK. The VIDI positioner alarm alerts the Network Manager that the hydrant position has moved from closed to open. If the change is unauthorised, it can be investigated immediately. It also logs all operations so patterns can be captured for illegal hydrant use which can help with prosecution.
Andrew Jervis, Senior DST Team Manager at HD Water, said:
“We are really looking forward to achieving real results with time and cost savings once the network is complete. We know we have
to improve and the VIDI technology is a great holistic foundation to ensure any gains achieved through leak detection and NRW reduction can be sustained by robust network management.”
Call David to learn more about smart water and how it can significantly improve your network.