For older water pipeline materials such as cast iron and asbestos cement, future pipe failure rates can be extrapolated from large volumes of existing historical failure data held by water utilities. However, for newer pipeline materials such as polyvinyl chloride (PVC), only limited failure data exists and confident forecasts of future pipe failures cannot be made from historical data alone. T...

This research verified the applicability and effectiveness of the ultrasonic monitoring of sediments stuck on the inner wall of polyvinyl chloride (PVC) pipes. For identifying the transmittance of acoustic energy and the speed of sound in the PVC material, the pulse-echo ultrasonic testing was conducted for PVC sheets of different thicknesses. To simulate the solidified sediment, the hot melt a...

To compare the effect of various pipe materials on biofilm formation, surface water was used as the test water source; plastic-based pipe materials (polyvinyl chloride-PVC, unplasticised polyvinyl chloride-UPVC, medium density polyethylene-MDPE) and cement-based pipe materials (cement and asbestos cement) are commonly used in drinking water distribution systems in South Africa as test pipe mate...

When compared to free chlorine, chloramines represent an established secondary disinfectant that may be utilized reduce disinfection by-product formation and improve residual stability. Maintaining acceptable in distribution systems however challenging due potential high maintenance costs associated with uni-directional flushing swabbing. This study was designed identify the primary sources of ...

Water authorities around the world are faced with the problem of ageing distribution networks and often only limited historical data on which to base a sound long term, cost efficient replacement policy. The LICAN approach to whole of life costing is introduced and a hypothetical case study is used to demonstrate the importance of such an approach. A selection of pipe networks utilizing differe...

This work aimed to determine the influence of different chlorine doses to inactivate of Listeria monocytogenes biofilm cells collected from six types of pipe materials, which are commonly used in household at different biofilm ages. A laboratory-scale simulated distribution system, that consists of a design based on six different pipe materials which are: polyvinyl chloride (PVC), polypropylene...

An inexpensive and radiolucent elbow can be built with a PVC pipe available at any home center or hardware store for less than $25 that allows elbow arthroscopy or open elbow surgery such as open reductions and internal fixation to be performed in the prone, "sloppy" lateral, or decubitus position.

The predominant microorganisms in samples taken from shower heads in residences in the Korean city "N" were Stenotrophomonas maltophilia, Sphingomonas paucimobilis, Acidovorax temperans, and Microbacterium lacticum. Legionella was not detected in this case. The volatile organic compounds (VOCs) vinylacetate, NN-DMA, cis-1,2-dichloroethylene, epichlorohydrin, and styrene were measured in five ty...

The failure of steel liner of pressure shafts of hydropower plants can have catastrophic consequences. The partial or total loss of the liner support’s rigidity is characterized by a local change of the hydro-acoustic properties and creates reflection boundaries for the water waves. This paper presents a new monitoring method for detecting and locating weak reaches by processing reflected water...

An experiment featuring waterhammer in viscoelastic pipes is presented in which the effects of pipe-wall viscoelasticity on waterhammer pressures are investigated. A large-scale pipeline apparatus made of polyvinyl chloride (PVC) at Deltares, Delft, The Netherlands, has been used to carry out waterhammer experiments. Tests have been conducted in a reservoir-pipeline-valve system consisting of a...