WET News

20 WET NEWS JUNE 2014 Water hammer is a serious problem for the water industry, with research blaming valve operations for half of supply interruptions. The challenge: Hammering out pressure surges T he issue of transient pres- sure surge (water ham- mer) in water networks has been a serious issue for water companies for some time. Transient pressure surge can occur as a result of net- work operations or interven- tions, particularly valve opera- tions, hydrant operations and pump starts and stops. The potential for structural damage of ageing distribution networks resulting in increased leakage and / or burst mains is significant and inevitably leads to customer supply interruptions. Research carried out by aca- demic institutions, and analy- sis of asset failures by water companies, into the causes and effects of transient surge has revealed that more than 50% of unplanned supply interrup- tions can be traced back to net- work activity, primarily valve operations, that has taken INSIGHT VALVES, DRIVES & ACTUATORS The training process has been rolled out to more than 500 operatives, as the training rig and training programme demonstrate how by changing the method of operation, these damaging transient surges can be avoided or substantially reduced place in the vicinity within the preceding seven days. Working in collaboration with Sheffield University and Severn Trent Water, Morrison Utility Services is spearheading a new 'Calm Networks' approach to valve operations. A purpose-built Calm Net- works training rig has been designed and constructed to demonstrate to operators of valves the potential, dramatic pressure surge consequences of operating distribution net- work valves in the traditional way and how, by changing the method of operation, these damaging transient surges can be avoided or substantially reduced. n Morrison Utility Services is delivering innovative 'Calm Networks' training to valve operators. A solution: A calming influence Y orkshire Water, Thames Water and Anglian Water have all engaged Morri- son Utility Services to design, supply and install a Calm Net- works training rig, along with a bespoke training programme to raise awareness and under- standing to all valve operators that is now in the process of be- ing rolled out to almost 500 valve operator employees. The rig consists of a closed loop of approximately 200m of 90mm diameter PE pipe fed by a heavy duty pump from a tank reservoir. Simulating a section of operational main, the rig can be adjusted to produce a varied range of flow velocities and pressures. The system is equipped with various valves, hydrants, PRV, MSM chamber and other appa- ratus to replicate equivalent net- work installations, configura- tions and conditions. Pressure variations Strategically positioned pres- sure sensors, capable of meas- uring pressure variations and pulses as short as 5/1,000ths of a second, are connected (via laptop) to a large display, ena- bling real-time graphical dis- play of pressure variations to demonstrate to trainees the pressure consequences of the operation of the various valves and other apparatus. The training programme is currently being rolled out to Thames Water employees and contractors authorised to oper- ate, or supervise operation of, assets on the network. Comprising both classroom and practical sessions, the training is structured to raise knowledge and awareness around three key activities that can impact performance: • Standard valve operations • Mains recharge • Bypassing of PRVs Richard Smith, contract manager, Capital Delivery at Thames Water is full of praise for the Calm Networks approach and the collaboration with Mor- rison Utility Services. He says: "This has been an exceptionally well thought-out training course that has really engaged our operatives. Since November 2013, we have put through 300 network operations staff, through the training, including operations director Bob Collington, and the feedback has been excellent. "We now look forward to seeing the benefits of this training and working with Morrison to identify ways in which we can develop this learning into the field." Adam Gosnold, executive director at Morrison Utility Ser- vices, comments: "Our aim with this initiative is to raise under- standing and awareness of the importance of modifying opera- tional practice in support of the ongoing drive to deliver strong customer service and improved SIM performance. "Evidence is already point- ing to a reduction in the number of burst mains and, conse- quently, unplanned customer supply interruptions." n for more information contact maureen.gaines@fav-house.com THE CONCEPT • The purpose-built Calm Networks training rig demonstrates to valve operators the potential, dramatic pressure surge consequences of operating distribution network valves • The rig comprises a closed loop of 200m of 90mm diameter PE pipe fed by a heavy duty pump from a tank reservoir • Pressure sensors, capable of measuring pressure variations and pulses as short as 5/1,000ths of a second, enable real-time graphical display of pressure variations • The system simulates a section of operational main NEED TO KNOW 1 More than 50% of unplanned supply interruptions can be traced back to network activity, primarily valve operations 2 The Calm Networks training concept is in the process of being rolled out to almost 500 valve operator staff 3 Thames Water has put 300 staff through the training since November 2013 4 Water hammer commonly occurs when a valve closes suddenly at the end of a pipeline system, and a pressure wave propagates in the pipe THE VERDICT • The training has "really engaged our operatives", says Richard Smith, contract manager, Capital Delivery at Thames Water • The training has led to a reduction in the number of burst mains and, consequently, unplanned customer supply interruptions SHARE YOUR OPINION... yoursaywn@fav-house.com "Our aim with this initiative is to raise understanding and awareness of the importance of modifying operational practice in support of the ongoing drive to deliver strong customer service and improved SIM performance" Adam Gosnold, Morrison Utility Services

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