Product category:
Pneumatic Valves and Controls
News Release from: Parker Hannifin | Subject: Yorkshire Water
Edited by the Engineeringtalk Editorial
Team on 09 May 2002
Efficient in-situ water main cleaning
and relining
Parker Pneumatic components are playing an integral role in ensuring the efficient operation of eight specially designed lining rigs supplied by Pipeway to Yorkshire Water.
Parker Pneumatic components are playing an integral role in ensuring the efficient operation of eight specially designed lining rigs supplied by Pipeway to Yorkshire Water to apply a rapid setting PU lining material to the inside of water mains - while still in the ground Each of the Pipeway, in-situ, 300C Series mains renovation spray lining rigs supplied to Yorkshire Water consists of a towable four-wheel trailer which houses two heated component storage reservoirs, a two-stage pumping system, trace heating circuit, PDACS (pipeway data acquisition and control system) electronic control system, umbilical hose and spinner/mixer assemblies
Operators first locate the pipe and dig two, 2m square holes up to 220m apart to expose it.
Access to the pipe is achieved by removing a one metre length section of pipe from each excavation.
The pipe inner is then cleaned by traditional rack boring or drag-scrapping methods.
Once cleaning and prelining CCTV inspection are complete the lining is applied.
The machine dispenses a two-pack resin system by centrifugal spray.
This is achieved by warming each resin system component while in the reservoir, which helps to reduce viscosity and aids pumping.
Thermal conditioning of the resin system components takes place inside the umbilical hose.
The hose is then pulled through the pipe and the spray head attached.
The pumps are started and once the on-board monitoring computer shows stable conditions (2-3min), the winch drive is started and the hose is withdrawn from the main.
The lining thickness of 1mm is obtained by holding the resin system flow constant and varying the linear speed of the spray head via closed loop control.
The resin takes less than 2min to harden.
A post lining CCTV survey is then carried out before reconnection and commissioning of the renovated pipe.
The hose was developed by Pipeway specifically for this application.
It consists of six inner core hoses (two for resin transfer, one air brake tube for bulk pneumatic feed to the spray head, and three for trace heating), four quad data cable bundles and two capillary nylon tubes encased in a 47mm OD composite polyurethane/Aramid sheath.
The combination of inner hose products and sheathing offers good service performance and acceptable abrasion resistance while maintaining the all important flexibility required for the tight operating environment inside a 3in nominal ID water main - the maximum ID operated is currently 18in.
Yorkshire Water is investigating the possibility of lining pipes up to 48in in diameter, in 200m sections.
Head loss is one of the disadvantages of pumping high viscosity resin systems through small bore hoses of 250m in length.
This is overcome by using reciprocating piston pumps (positive displacement) with 14in diameter air motor pistons to get the required mechanical advantage.
Parker Pneumatic 1in FRLs (filter/regulator/lubricator) satisfy the huge supply demand air motors of this size place on the conditioning equipment.
The Pipeway rig also uses separate Parker P3E series FRLs in series with Parker Lucifer solenoid valves which control pneumatic supply to loading pumps, to feed the metering pump, and for the application spray head and for purging/venting of nitrogen screening in the reservoirs. Request a free brochure from Parker Hannifin ...
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