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Marc Edwards - One of the best experts on this subject based on the ideXlab platform.

  • Interactive Effects of Copper Pipe, Stagnation, Corrosion Control, and Disinfectant Residual Influenced Reduction of Legionella pneumophila during Simulations of the Flint Water Crisis.
    Pathogens (Basel Switzerland), 2020
    Co-Authors: Rebekah L. Martin, Owen R. Strom, Amy Pruden, Marc Edwards
    Abstract:

    Flint, MI experienced two outbreaks of Legionnaires’ Disease (LD) during the summers of 2014 and 2015, coinciding with use of Flint River as a drinking water source without corrosion control. Using simulated distribution systems (SDSs) followed by stagnant simulated premise (i.e., building) plumbing reactors (SPPRs) containing cross-linked polyethylene (PEX) or Copper Pipe, we reproduced trends in water chemistry and Legionella proliferation observed in the field when Flint River versus Detroit water were used before, during, and after the outbreak. Specifically, due to high chlorine demand in the SDSs, SPPRs with treated Flint River water were chlorine deficient and had elevated L. pneumophila numbers in the PEX condition. SPPRs with Detroit water, which had lower chlorine demand and higher residual chlorine, lost all culturable L. pneumophila within two months. L. pneumophila also diminished more rapidly with time in Flint River SPPRs with Copper Pipe, presumably due to the bacteriostatic properties of elevated Copper concentrations caused by lack of corrosion control and stagnation. This study confirms hypothesized mechanisms by which the switch in water chemistry, Pipe materials, and different flow patterns in Flint premise plumbing may have contributed to observed LD outbreak patterns.

  • Flow-induced failure mechanisms of Copper Pipe in potable water systems
    Corrosion Reviews, 2018
    Co-Authors: Siddhartha Roy, Jeffrey M. Coyne, Julia A. Novak, Marc Edwards
    Abstract:

    AbstractErosion or velocity-induced Copper Pipe corrosion is a significant problem in potable water systems, especially hot water recirculation systems. The little scientific work done in freshwater has not always been able to scientifically isolate the key factors causing these failures; in fact, most existing recommendations rely on anecdotal and/or experiential knowledge from forensic analysis of field failures, which are not confirmed by complementary laboratory research. Consequently, this comprehensive review summarizes prior observations that include mechanical and electrochemical attack induced by water chemistry, temperature, velocity, hydrodynamic conditions, presence of particulate matter, and other variables thought to influence/exacerbate erosion corrosion. Distinct phenomena thought to contribute to erosion corrosion or “flow-induced failure”, including concentration cell corrosion, cavitation, particle/bubble impingement, and high velocity impingement, are explored in detail along with conventional erosion corrosion testing methods. Existing recommendations to prevent erosion corrosion in Copper Pipes are evaluated and inconsistencies in available guidelines are examined.

  • Impact of Leak Size, Pipe Wall Thickness, Water Pressure, and Leak Orientation on Autogenous Metallic Pipe Leak Repair
    CORROSION, 2017
    Co-Authors: Min Tang, Marc Edwards
    Abstract:

    The effectiveness of autogenous metallic (iron and Copper) Pipe leak repair as a function of leak size, Pipe wall thickness, water pressure, and leak orientation was examined at water pressures up ...

  • Technical Note: Increased Distance Between Galvanic Lead:Copper Pipe Connections Decreases Lead Release
    CORROSION, 2012
    Co-Authors: J. St. Clair, C. Stamopoulos, Marc Edwards
    Abstract:

    It has recently been proposed that lead contamination of drinking water arising from galvanic corrosion of lead and Copper Pipe will be minimized if the lead and Copper Pipes are brought into direc...

  • Impact of advanced water conservation features and new Copper Pipe on rapid chloramine decay and microbial regrowth.
    Water research, 2011
    Co-Authors: Caroline K Nguyen, Carolyn Elfland, Marc Edwards
    Abstract:

    Taste and odor issues occurring in new buildings were attributed to rapid loss of chloramine residual, high levels of microbes in the potable water system, and high water age due to use of advanced water conservation devices. Laboratory experiments confirmed that chloramine could decay rapidly in the presence of new Copper Pipe, providing a possible explanation for the rapid disinfectant loss in the new buildings. Higher temperature and lower pH also accelerated the rate of chloramine decay in Copper Pipes. The reaction was slowed by the addition of phosphate inhibitor or aluminum, which presumably formed barriers between the Pipe wall and the chloramine in the bulk water. Additional research is needed to better understand how to maintain high quality water in buildings while also conserving water.

Qiang Xiao - One of the best experts on this subject based on the ideXlab platform.

  • a study of ceramic lined compound Copper Pipe produced by shs centrifugal casting
    Materials Letters, 2005
    Co-Authors: Zhongze Du, Hanguang Fu, Hanfeng Fu, Qiang Xiao
    Abstract:

    Abstract In this study ceramic-lined compound Copper Pipe (CLCCP) was produced by self-propagating high-temperature synthesis (SHS) and centrifugal casting technology. The effects of additives such as SiO2, CrO3, Na2B4O7 and ZrO2 on the densification degree, combining strength and the toughness of the ceramic layer were of prime interest. The results show that the densification degree of the ceramic layer can be improved by adding SiO2 and CrO3 in the thermite. This improvement correlated with the reduction of porosity of ceramic layer. The combining strength is increased through the addition of a suitable amount of Na2B4O7. The highest fracture toughness of ceramic layer is obtained at 7 wt.% of ZrO2 in thermite. The CLCCP shows excellent service properties when it is used in tubular billet crystallizer, including the prevention of cracks and flakes.

  • A study of ceramic-lined compound Copper Pipe produced by SHS–centrifugal casting
    Materials Letters, 2005
    Co-Authors: Qiang Xiao
    Abstract:

    Abstract In this study ceramic-lined compound Copper Pipe (CLCCP) was produced by self-propagating high-temperature synthesis (SHS) and centrifugal casting technology. The effects of additives such as SiO2, CrO3, Na2B4O7 and ZrO2 on the densification degree, combining strength and the toughness of the ceramic layer were of prime interest. The results show that the densification degree of the ceramic layer can be improved by adding SiO2 and CrO3 in the thermite. This improvement correlated with the reduction of porosity of ceramic layer. The combining strength is increased through the addition of a suitable amount of Na2B4O7. The highest fracture toughness of ceramic layer is obtained at 7 wt.% of ZrO2 in thermite. The CLCCP shows excellent service properties when it is used in tubular billet crystallizer, including the prevention of cracks and flakes.

Simo O. Pehkonen - One of the best experts on this subject based on the ideXlab platform.

  • Studies on the magnetic water treatment in new pilot scale drinking water system and in old existing real-life water system
    Journal of Water Process Engineering, 2016
    Co-Authors: Martti Latva, Jenni Inkinen, Jaakko Rämö, Tuija Kaunisto, Riika Mäkinen, Merja Ahonen, Jaana Matilainen, Simo O. Pehkonen
    Abstract:

    Abstract Influence of altering magnetic field on chemical properties of water, scale formation and morphology was studied using polyethylene and Copper Pipes located both in a laboratory pilot-system and in an apartment complex formed by five different buildings each having four or five different homes. In the pilot network, magnetic field decreased calcium scaling by 15% in the both studied piping materials. Also, surface film on the Copper Pipe appeared to be less compact by the magnetic exposure. In the studies conducted in the apartment complex, magnetic field effectively mobilized earlier accumulated iron and Copper from the Copper Pipe surfaces especially dealing with a hot water circuit.

Dídia Covas - One of the best experts on this subject based on the ideXlab platform.

  • Transient vaporous cavitation in a horizontal Copper Pipe
    Journal of Hydraulic Research, 2017
    Co-Authors: Alexandre Kepler Soares, Nuno M. C. Martins, Dídia Covas
    Abstract:

    ABSTRACTThis research focuses on the analysis of transient cavitating flow in a horizontal Copper Pipe. Experiments have been conducted in a reservoir-Pipe-valve Copper Pipe-rig to collect transient pressure data with and without cavitation. A hydraulic transient solver incorporating unsteady friction losses and distributed cavitation flow (discrete gas cavity model) has been developed. The system behaviour and the obtained transient pressure signal have been compared with the experimental results for sloping Pipes reported in previous studies and a good agreement has been observed. Numerical results are compared with collected data and effects related to the unsteady friction losses and to the occurrence of transient vapour pressures are discussed.

  • Experimental distinction of damping mechanisms during hydraulic transients in Pipe flow
    Journal of Fluids and Structures, 2016
    Co-Authors: David Ferras, Pedro Manso, Anton Schleiss, Dídia Covas
    Abstract:

    Abstract The aim of the present paper is to contribute to the identification of the principal mechanical–hydraulical relationships during hydraulic transients by means of the analysis of observed transient pressure and strain waves in different Pipe rigs. Four different experimental set-ups are analysed: a straight Copper Pipe with either moving or anchored downstream Pipe-end, a coil Copper Pipe and a coil polyethylene Pipe. Discussion highlights differences in the response of each system in terms of wave shape, damping, and dispersion. The straight Copper Pipe behaviour, for an anchored Pipe-end, has shown the closest dynamic response to the expected one from classical waterhammer theory, being unsteady friction the most relevant damping mechanism. Fluid structure interaction dominates when the valve is released in the straight Copper Pipe and also has an important role in the coil Copper Pipe. Viscoelasticity dominates in the polyethylene Pipe.

Liansheng Wang - One of the best experts on this subject based on the ideXlab platform.

  • Influence of organic matter on orthophosphate corrosion inhibition for Copper Pipe in soft water
    Corrosion Science, 2004
    Co-Authors: Cheng Sun, Liansheng Wang
    Abstract:

    The adverse effects of organic matter on orthophosphate corrosion inhibition for Copper Pipe in simulated soft water were investigated. Sodium alginate and fulvic acid were selected to simulate extracellular polymeric substance produced by bacteria and natural organic matter in potable water. The results showed that the doses of organic matters, pH values and stagnation times had significantly affected on the function of orthophosphate corrosion inhibition for Copper Pipe in soft water. More soluble Copper release was observed in low levels for sodium alginate (1 mg/l as TOC) and in high concentration for fulvic acid (16 mg/l as TOC). When the concentration of fulvic acid was high, the 2-week aged Copper Pipe released more soluble Copper than the 6 and 12-month aged Copper Pipe. The soluble Copper release increased with the reduction of initial pH value. Effect of stagnation time on soluble Copper release from different aged Copper Pipe in soft water was highly variable. Compared to the system of no organic matters, organic matters markedly decreased the efficiency of orthophosphate corrosion inhibition for Copper Pipe in soft water.