Leakage innovations dominate awards shortlist
A range of solutions for leakage management and pipe repair dominate the Water Industry Achievement Awards' innovation categories. Natasha Wiseman rounds up the finalists
Leakage specialist i2O's methodology of Advanced Pressure Management in water distribution networks means that the pressure reducing valve (PRV) outlet pressure is continuously adjusted so that the pressure is always kept at the minimum necessary to guarantee a good level of service. To improve on existing solenoid technology, the company has developed the advanced pilot valve (APV), which is attached to the outlet pressure in place of a conventional pilot valve.
The APV smoothly adjusts the pressure in response to the i2O controller. The i2O server can receive and store data, update control algorithms, handle alarms and generate reports.
Platelets plug leaks
Yorkshire Water and Brinker Technology have developed a water pipe repair technique using polymer particles, or Platelets, which are injected into a leaking pipe. They are carried in the flow to the vicinity of the leak where the differential pressure pulls them into the leak to seal it. (See WWT February 2009)
Modulating flow reduces leakage
The most cost effective way to reduce leakage is to reduce pressure in the supply system and there are various ways to flow modulate the outlet pressure. The Model 7PM Flow Compensated Pressure Management System from Premium Bermad has been engineered as an adaptation to link between the valve position and outlet pressure.
An indicator rod is attached to the valve stem by a universal joint and the rod passes through an O-ring seal to minimise friction. The cam on the rod is adjustable and operates a roller pushing back a lever as the valve opens; this in turn tensions the pilot spring causing an increase in the outlet pressure.
When the demand declines the valve moves towards the closed position and the outlet pressure drops. Adjustable stops are provided to limit the travel of the lever preventing excessive pressure.
Camera kit enables live inspection
Balfour Beatty Utility Services' Vertical Valve Injection Kit is a camera system that enables quick inspection of live water mains through entry of existing water network hydrants, quadrenas or air valves. The camera system can now carry out visual inspection and leak detection on any sizes of small-bore pipe up to 100m from the access point.
This eliminates the need for excavation as existing fire hydrants, for which supply can be maintained, can be used. Trials are underway for a sonde tracking device to detect where the camera is in the pipe and a hydrophone listening device to be added to the system.
Ice pigging gets muck out
A technique for cleaning pipes and ducts by pumping a thick ice slurry through them has been developed by the University of Bristol with the support of Bristol Water. The slurry is transported by specialist tanker then pushed into potable water pipes via standard hydrants.
It forms an 'ice pig' in the pipe and mains water is then used to propel the pig along the pipe. At the next hydrant, downstream, it is forced out, taking the sediment it has collected with it.
Wizard helps hydrant replacement
Morrison Utility Services' Hydrant Wizard is a 'bagging off' technology borrowed from the oil and gas industry to enable hydrant replacement. It works by drilling an access hole under pressure in the riser/supply pipe immediately underneath the hydrant.
A launch tube containing an inflatable bag is then inserted under live, full pressure, operating conditions through this access hole. The bag is then launched into the riser pipe immediately below the faulty hydrant and inflated with chlorinated water to 2 bar above measured mains pressure. This isolates the hydrant from the mains allowing it to be replaced without impacting on mains water supply.
Iron solution to traverse Hadrian's Wall
An innovative approach to existing trenchless technology was needed when the replacement of the Tyneside North Circular main meant traversing Hadrian's Wall and other infrastructure. The base solution chosen for the trenchless sections was to pipe jack a concrete pipe and then insert a pressured pipeline through the casing. Due to the working pressure and steel needing to be welded under tightly controlled conditions, ductile iron was chosen as the most cost effective material solution.
Saint Gobain's PAM Universal was proposed because of its unique boltless restraint solution, featuring a push fit, double chambered socket design, which provides as secure seal and guarantees an immensely strong pipe-to-pipe anchorage system.