Types Of Pipe Materials Research Articles

The sewer advances: How to select eco-friendly pipe materials for environmental protection

Sewer pipe materials exhibit diverse inner-surface features, which can affect the attachment of biofilm and influence microbial metabolic processes. To investigate the role of the type of pipe material on the composition and metabolic capabilities of the adhering microorganisms, three sets of urban sewers (High-Density Polyethylene Pipe (HDPE), Ductile Iron Pipe (DIP), and Concrete Pipe (CP)) were constructed. Measurements of biofilm thickness and environmental factors revealed that the thickest biofilm in CP pipes reached 2000 μm, with ORP values as low as −325 mV, indicating a more suitable anaerobic microbial habitat. High-throughput sequencing showed similar relative abundances of genera related to carbon and sulfur metabolism in the DIP and CP pipes, whereas HDPE exhibited only half the relative abundance compared to that found in the other pipes. To explore the impact of pipe materials on the mechanisms of microbial response, a metagenomic approach was used to investigate the biological transformation of carbon and sulfur in wastewater. The annotations of the crucial enzyme-encoding genes related to methyl coenzyme M and sulfite reductase in DIP and CP were 50 and 110, respectively, whereas HDPE exhibited lower counts (25 and 70, respectively). This resulted in significantly lower carbon and sulfur metabolism capabilities in the HDPE biofilm than in the other two pipes. The stability of wastewater quality during the transmission process in HDPE pipes reduces the metabolic generation of toxic and harmful gases within the pipes, favoring the preservation of carbon sources for sewer systems. This study reveals the variations in carbon and sulfur metabolism in wastewater pipe systems influenced by pipe materials and provides insights for designing future sewers.

Perbandingan Penggunaan 3 Jenis Pipa untuk Sistem Penyediaan Air (Kajian Kasus Kawasan Industri Terpadu Kabupaten Batang)

Batang Regency is one of the areas located on the north west coast of Central Java province. Batang Regency is located in a strategic position, this area is traversed by primary arterial roads that connect West Java and DKI Jakarta with cities in Central Java and East Java Provinces. Batang Regency is divided into 15 sub-districts consisting of 239 villages, 9 sub-districts, 936 hamlets, 3,680 neighborhood units (RT) and 1,009 community units (RW). The total area of Batang Regency is 78,864.16 Ha. The widest sub-district is Subah District, which is 83.52 Ha (10.59%), while the smallest is Warungasem District, which is 23.55 Ha (2.99%) of the total area of Batang Regency. The Central Government's program to encourage the sector to strengthen the industrial sector in Indonesia, namely one of the developments in the Batang industry. The Government provides supporting facilities in the development of the Batang Industrial area through APBN financing. The Batang Industrial Estate has around 4,300 hectares of land to develop, for the first phase it will develop a land area of 450 hectares. To support the supply of drinking water in this area, PERUMDA of Sendang Kamulyan Drinking Water, Batang Regency will supply drinking water which will take water from the raw water source of the Bangkangan spring at 100 liters/second and will be supplied to the Industrial Area at 80 l/s. For the analysis of the drinking water supply system in this industrial area, the Epanet 2.2 program will be used by comparing the hydraulic analysis of the use of HDPE, PVC and iron pipe types/materials, residual pressure and diameter as well as calculating the amount of investment based on the type of pipe material. The results of running Epanet 2.2 on HDPE, Iron and PVC pipes with remaining water pressure at the end of the pipe at the KITB Junction, the remaining pressure is more than 10 meters, meaning that the water has flowed with sufficient criteria in the service area. Based on the analysis taking into account efficiency, the selected pipe is HDPE with an investment value of Rp. 20,273,230,410. The recommendations given for SPAM KITB, can use HDPE pipes, apart from lower costs HDPE pipes have a better roughness coefficient than PVC pipes and iron pipes and can also minimize pipe leaks. Lessons from this study with Epanet Software can calculate water hydraulics in the piping system such as water velocity, the furthest remaining water pressure can be known quickly, can determine the type and specifications of pipes used for the study area and known cost efficiency based on the type of iron, PVC and HDPE pipes.

Chlorine Decay Simulation in Real Water Distribution System Using Epanet Program

Abstract Deterioration of treated drinking water intended for consumption during distribution may be due to physical, chemical or microbiological changes that occur in the water. In addition, the type of pipe material and disintegration of a disinfectant agent can affect the quality of the water supplied. Therefore, the research approach is to simulate the decay residual Cl2 through potable water distribution networks produced by a desalination plant of Oran city in western Algeria. EPANET 2.0 software was used for estimating and predicting Cl2 concentration at different water network points. The value of bulk flow decay coefficient (Kb) is set to −1,99 day−1 for a 50-year-old steel pipe, value for the wall decay coefficient (Kw) was determined using a trial-and-error procedure and assumed to be −1,2 day−1. An efficient model with an extended simulations period of 72 h can plot spatial and temporal variations of residual Cl2 concentrations at all links and nodes. Cl2 is injected at the El Mactaa desalination plant, with a concentration of 0.6 mg/l permanently. As well, it was observed that 51.33% of the Cl2 loss is due to pipe wall reaction, while 42.34 and 6.33% represent the bulk and tank reactions respectively. The results show that the range of residual Cl2 (0.11-0,45 mg/l) and most of the measured values are less than are below the minimum authorized threshold (0.2 – 0.5 mg/l) WHO standard. Therefore, it is recommended to rehabilitate the old water transfer pipes and re-chlorination stations were necessary to add into network. Statistical analysis shows that the calculated results correspond well to the observed data. EPANET can follow the Cl2 concentration in the drinking water network produced by El Mactaa desalination plant. It is a research tool to improve our understanding of water movement in the distribution system.

Utilizing Ground-Penetrating Radar for Water Leak Detection and Pipe Material Characterization in Environmental Studies: A Case Study

Detecting and mapping subsurface utilities in urban areas is crucial for identifying defects or damages in drinking and sewage pipes that can cause leaks. These leaks make it difficult to accurately characterize the pipes due to changes in their reflective properties. This study focused on detecting leaks originating from underground pipes and distinguishing between these various types of pipes. It also aimed to create a visual fingerprint model that displays the reflection characteristics of these pipes during different leak conditions, enabling efficient maintenance and handling procedures on the pipes. To achieve this, a finite-difference time-domain (FDTD) method was used to simulate two types of pipe materials with and without leak areas to construct different scenarios. Additionally, a ground-penetrating radar (GPR) field survey was conducted using a 600 MHz antenna in a part of the El Hammam area on Egypt’s northwest coast. The simulated images produced with numerical modeling were compared with the radar profiles obtained using GPR at particular locations. The numerical simulations and radar profiles demonstrated the noticeable influence of water leaks from the different pipes, wherein the reflection of saturated soil waves was interrupted due to the presence of saturated soil. Envelope and migration techniques were employed in a new application to accurately distinguish between different pipe types, specifically focusing on leak areas. The strong correlation between the real radar profile and the specific signal of a water pipe leak in the simulated models suggests that GPR is a reliable non-destructive geophysical method for detecting water pipe leaks and distinguishing between the different pipe materials in various field conditions. The simulated models, which serve as image-matching fingerprints to identify and map water pipe leaks, help us to comprehend reality better.

Legionella pneumophila Risk from Air–Water Cooling Units Regarding Pipe Material and Type of Water

Legionellosis is a respiratory disease related to environmental health. There have been manifold studies of pipe materials, risk installations and legionellosis without considering the type of transferred water. The objective of this study was to determine the potential development of the causative agent Legionella pneumophila regarding air-water cooling units, legislative compliance, pipe material and type of water. Forty-four hotel units in Andalusia (Spain) were analysed with respect to compliance with Spanish health legislation for the prevention of legionellosis. The chi-square test was used to explain the relationship between material-water and legislative compliance, and a biplot of the first two factors was generated. Multiple correspondence analysis (MCA) was performed on the type of equipment, legislative compliance, pipe material and type of water, and graphs of cases were constructed by adding confidence ellipses by categories of the variables. Pipe material-type of water (p value = 0.29; p < 0.05) and legislative compliance were not associated (p value = 0.15; p < 0.05). Iron, stainless steel, and recycled and well water contributed the most to the biplot. MCA showed a global pattern in which lead, iron and polyethylene were well represented. Confidence ellipses around categories indicated significant differences among categories. Compliance with Spanish health legislation regarding the prevention and control of legionellosis linked to pipe material and type of water was not observed.

Hydraulic studies of pressure pipes made of various materials

Introduction. To solve the problem of water shortage for irrigation in the city of Kerbala (Iraq), for the first time, a decision was made to use treated wastewater from urban wastewater treatment plants. Transportation of water from treatment facilities to irrigated lands is carried out through a pipeline in a pressure mode. The article compares the results of simulation modeling of WaterCAD V8i at various flow rates in a pressurized water supply system with the results of laboratory studies for three types of pipe materials (100 mm diameter steel pipe with polymer coating, 100 mm diameter polyethylene pipe and 100 mm diameter steel pipe with cement-sand coated (diameter 90 mm)). The purpose of the work is to verify the results obtained in the WaterCAD V8i program by conducting experiments for various types of pipes.&#x0D; &#x0D; Materials and methods. During the experiment, the characteristics of the flow were studied.&#x0D; &#x0D; Results. Comparison of the experimental results with the results obtained using the WaterCad V8i simulation model showed that the hydraulic parameters (pressure loss, friction coefficient) are close in values, but the WaterCad V8i program recorded higher values for pipes (steel pipe with a diameter of 100 mm with a polymer coating and a polyethylene pipe with a diameter of 100 mm). The high convergence of the results for a number of hydraulic parameters can be noted.&#x0D; &#x0D; Conclusions. The results of the work carried out by comparing the experimental data with the calculated ones obtained using the WaterCAD V8i program allow us to conclude that it can be widely used in practice to determine the hydraulic performance of pipelines.

Water and biofilm in drinking water distribution systems in the Netherlands

To keep the high quality of drinking water in the future for non-chlorinated drinking water systems, knowledge about the variables that most strongly affect this quality is necessary in order to know where to focus on and possibly even change aspects of drinking water production and distribution. Therefore, the aim of this study was to investigate which variables (source of drinking water, growth potential and pipe material type) have the biggest influence on bacterial community composition and biomass concentration of drinking water and biofilm in distribution systems. Ten different distribution systems were sampled for water and biofilm, obtained from four different pipe materials, throughout the Netherlands. The distribution systems are supplied either with drinking water produced from groundwater or surface water, and differ in drinking water quality parameters such as the growth potential. We found a significant relationship for growth potential and ATP concentration in water, but for the ATP in the biofilm none of the parameters showed a significant effect. Furthermore, the source of the drinking water and the pipe material did not significantly affect the ATP concentration in water and biofilm. The bacterial composition of in both water and biofilm was significantly different between distribution systems delivering water with low and high growth potential and between drinking water produced from groundwater or surface water. In contrast, the different pipe materials did not significantly affect composition of biofilm-associated communities. We conclude from these results that the growth potential of the treated water best explains the variation in biomass and bacterial composition in water and biofilm of non-chlorinated drinking water distribution systems followed by the drinking water source, whereas pipe materials seem to be of lesser importance.

Impact of pipe material on the wall reaction coefficients and its application in the rehabilitation of water supply system of San Pedro Nexapa, State of Mexico

Abstract One of the major challenges faced by water companies around the world is the high level of chlorine losses in distribution networks. This paper presents an experimental study to examine chlorine loss in different types of pipe materials and select the ones with low chlorine demand for the rehabilitation of the water distribution network of San Pedro Nexapa, State of Mexico. The materials investigated include: polyvinyl chloride (PVC), galvanized steel (GS), polypropylene (PP) and high-density polyethylene (HDPE). A 24-h chlorine consumption study was performed in a simulated water distribution network to assess the impact of wall reaction coefficient on chlorine decay. Four sets of independent pipe loops of 50 mm in diameter and 12 m in length were used. Two different scenarios were considered based on different initial chlorine concentration (1.21 mg/L and 1.60 mg/L). Samples were collected at each loop at two-hour intervals and physicochemical analyses were conducted. Results from the experimental distribution network showed that the wall coefficient values for GS, HDPE, PP and PVC were 0.165 h−1, 0.059 h−1, 0.043 h−1 and 0.026 h−1, respectively. Experimental results showed that wall reaction coefficient values depend on initial chlorine concentration and the characteristics of pipe material. The rate of free chlorine decay was found to be faster in steel pipe and slower in the plastic pipes. Based on its having the lowest chlorine demand compared with the other pipes, PVC pipe would be selected to rehabilitate Nexapa water distribution network, State of Mexico. The wall coefficients from the experimental study were incorporated into EPANET through four simulation runs to predict chorine decay of San Pedro Nexapa water distribution network, State of Mexico. In the PVC and PP pipes higher residual chlorine concentrations were observed that ranged from 0.30 to 0.90 mg/L and 0.50 to 0.95 mg/L, respectively. This study is important for utilities to operate their system effectively and protect public health.

Estimation of chloramine decay in drinking water distribution systems

When compared to free chlorine, chloramines represent an established secondary disinfectant that may be utilized to reduce disinfection by-product formation and improve residual stability. Maintaining an acceptable residual in distribution systems however may be challenging due to potential high maintenance costs associated with uni-directional flushing and swabbing. This study was designed to identify the primary sources of chloramine demand for a distribution system receiving surface and groundwater. Decay in the bulk water was quantified using a bottle point method. Bench-scale pipe section reactors (PSRs) were utilized to evaluate decay associated with cast‑iron and polyvinyl chloride (PVC) pipe sections that had been harvested from a distribution system, as well as to allow comparisons with new pipe material. Bulk water decay was compared to that observed in PSRs at flow rates of 0.03 m/s and 0.09 m/s, representative of distribution system conditions. Pipe material type and associated surface conditions were identified as the most critical factors influencing decay. Observed first-order decay rates for harvested cast‑iron pipe with an established microbial community and metal/silicate scale were significantly higher than those for PVC. In contrast, first-order decay rates for harvested PVC were comparable to new pipe, with water velocity exerting a negligible impact. Overall, these results reinforce the importance of determining the primary sources of chloramine decay in distribution systems.

Investigation of Pump Failure-Induced Waterhammer Waves: A Case Study

Abstract This study analyzes the effect of the pipe material type on the transient flow behavior in a pumping system due to an accidental pump shutdown. The material types addressed in this study include steel and high- or low-density polyethylene (HDPE) or (LDPE), involving elastic and plastic rheological pipe-wall behavior. The numerical solution is developed based on the method of characteristics used for the discretization of the extended one-dimensional pressurized-pipe flow model, incorporating the Kelvin-Voigt and Vitkovsky rules. Experimental data from the literature were used to validate the numerical solver. The proposed numerical algorithm is then used to investigate the transient pressure-wave behavior induced by the power failure to a pumping station composed of an inline connection using different pipe material types. The findings show the severity of such a scenario, in terms of the magnitudes of induced up-surge and down-surge pressure waves. Furthermore, this research demonstrates that plastic pipe-wall materials allow for substantial attenuation of surge magnitude in conjunction with the expansion of the period of pressure-wave oscillations. The observed attenuation and expansion effects are also found to be highly dependent on the plastic material type. In this respect, the findings indicate that the (LDPE-steel) piping system's specific layout allows for the best tradeoff between the two last effects.

Heat transfer analysis of single and double U-tube borehole heat exchanger with two independent circuits

Borehole heat exchanger (BHE) is a very suitable and cost-effective technology for heat storage and extraction of heat from the ground. In this paper, comprehensive analysis of major influencing parameters on thermal performance of single U-tube BHE (sBHE) and double U-tube BHE (dBHE) was performed by using validated numerical heat transfer model. Combined effect of increasing borehole size and soil or grout thermal conductivity (for different cases of shank spacing) on performance of sBHE and dBHE was studied. Detailed comparative analysis of thermal performance was made among sBHE and dBHE with small and large borehole sizes. The impact of borehole depth and diameter, fluid inlet temperature, mass flow rate, U-tube pipe material type and diameter on total heat transfer per unit borehole depth, borehole thermal resistance and thermal effectiveness was also investigated. The simulation result revealed that when the shank spacing is kept at high or low value in sBHE and dBHE (both with small and large borehole size), dBHE with larger borehole size has the highest thermal performance while sBHE with smaller borehole size has the lowest performance; and the highest and the lowest thermal resistance is obtained for sBHE with smaller borehole size and dBHE with larger borehole size, respectively. Grout with high thermal conductivity is preferred in terms of improving thermal effectiveness and reducing thermal resistance of the BHE when the soil thermal conductivity is sufficiently high; while low grout thermal conductivity is preferred with large borehole size and high shank spacing. For high soil thermal conductivity (4W/m.K), the heat transfer rate per unit borehole depth increases with grout thermal conductivity to a maximum value; and then further increasing of the grout conductivity results in smooth declining of the heat transfer in the BHE. Thus, ground and grout thermal conductivity have an optimal range to achieve a lower value of the BHE thermal resistance, and consequently for better BHE sizing. With increasing fluid inlet temperature (15oC to 42oC), the total heat transfer is improved by 51.5 W/m and 36.2 W/m for dBHE and sBHE respectively; and more heat is injected into the borehole when dBHE is used than sBHE, particularly at higher inlet temperature showing that dBHE is preferable than sBHE for system that works with higher fluid inlet temperature. The result obtained can be used as a quick reference for the design, operation optimization and performance study of ground coupled heat pump system where BHE is used as aborehole thermal energy storage.

Behaviour simulation of a main pipe depending on it’s execution material, in a non-steady flowing state (water hammer)

The current paper presents the optimal ways for choosing appropriate devices in order to protect the pressurized hydraulic installations in a water supply system, against water hammer phenomena. The case study done it in this research paper presents a hydraulic system formed by a main water pipe, and it’s behaviour regarding the water hammer phenomena, taking into account 3 types of pipe execution materials (ductile iron, polyethylene and glass reinforced pipe). The study includes also the protection equipment’s need it for each type of pipe material. Hydraulic simulation was made using a numerical calculation model, designed with a software special for non-steady flowing state in pressurized systems, called Bentley Hammer v.10i..

Effect of geo-climatic conditions and pipe material on heating performance of earth-air heat exchangers

Climatological and geological site classification intended for Earth-Air Heat Exchanger Technology (EAHE) is an important factor in the design, implementation and optimal operation of such system. In this context, this paper presents an investigation on the heating performance and operating feasibility of two EAHEs in three different geo-climatic regions in Algeria. First, the performances of the EAHEs were experimentally studied in the temperate Oran climate and the corresponding results were used for validation of the numerical part. The experiment allowed to analyze the effect of the pipe material on the performance of the two EAHEs that are made of different materials (PVC and Zinc). After validation of the numerical part, the study was extended to three different climates including a temperate climate for Oran, an arid climate for Bechar and a steppe climate for El-Bayadh cities. For these climates, the heating study is rarely considered in this context. Furthermore, a sensitivity analysis was conducted in order to evaluate the operating feasibility of the EAHEs in the considered regions. The results revealed that the Zinc EAHE is more efficient in a temperate climate with a COP of 9.5 than in an arid or steppe climate with a COP of 8.2 or 8.1, respectively. However, the PVC EAHE is much better in an arid climate with a COP of 9.4 than in a temperate or steppe climate with a COP of 7.6 or 8.4, respectively. Otherwise, both EAHEs exhibited similar behavior in a steppe climate. The results show that the thermal performance of EAHE mainly depends on geo-climatic conditions and the type of pipe material.

Economical velocity through pipeline networks “Case Studies of Several Different Markets”

In this research, a new concept for the economic pipeline design was presented. The new concept is called economic design velocity. Considering a simple pipeline, a mathematical model was presented to relate different types of annual costs to the design velocity of pipeline. At least annual cost, the design velocity is called the economic velocity. Relationships between design velocity and different parameters related to the pipeline were presented to show the effect of pipeline length, static head, capital recovery factor, flow discharge, pipeline accessories, as well as excavation and backfill on the economic design velocity. Three different markets were considered to estimate the annual cost of different components of pipeline. These markets are: Lebanese, United States, and Indian. Two different types of pipe materials were considered: ductile iron and high density polyethylene pipes. The economical velocities for ductile iron were 1.00 m/s, 1.70 m/s, and 0.90 m/s for Lebanon, United States of America, and India, respectively. The economical velocities for high density polyethylene were 1.75 m/s, 1.00 m/s, and 1.95 m/s for Lebanon, United States of America, and India, respectively. The Economical velocities of Indian and Lebanese markets were very similar to each other. The economical velocity for India and Lebanon is low while that for United States of America is high for ductile iron; whereas the economical velocity for India and Lebanon is high while that for United States of America is low for high density polyethylene.

Life cycle assessment of pipes and piping process in drinking water distribution networks to reduce environmental impact

Drinking water distribution networks (DWDNs) are one of the most significant components of urban water systems. Although the environmental aspects of DWDNs’ construction could be very important, limited studies have considered environmental impact (EI) of DWDN. Using Life Cycle Assessment, this paper evaluates the EI of five types of pipe materials in DWDNs, including polyvinyl chloride (PVC), high-density polyethylene (HDPE), ductile iron (DI), fibrocement, and steel. The results indicate that, in the production phase, DI has more EI in most impact categories. In the global warming category of production phase, the EI of one meter of 200 mm DI is 128 kg CO2 eq, six times greater than PVC. With respect to the installation phase, a specific trench was considered for each pipe type to compare the EI of different trenches. In this phase, due to the EI of bedding materials, fibrocement trench has the highest impact. To illustrate the applicability of the proposed method, a part of the Tehran DWDN was selected as a case study, with results demonstrating that a reduction of between 12 and 26% is achievable in the EI of the DWDN from its pipes and piping process by substituting for some of the pipes with environmentally friendly materials.

The Unfavourable Impact of Street Traffic on Water Distribution Pipelines

This article analyses the relation between the failures that occurred in the water supply network and the road traffic in the city of Cluj-Napoca in Romania. The calculations in this case study were made using the Autodesk Robot Structural Analysis Professional 2011 software. In the case study, the following types of pipes were analysed: steel, gray cast iron, ductile cast iron and high density polyethylene (HDPE). While in most studies only a few sections of pipelines, several types of pipelines and certain mounting depths have been analysed, the case study presented analyses the entire water supply system of a city with a population of 324,576 inhabitants, whose water supply system has a length of 479 km. The results of the research are useful in the design phase of water distribution networks, so depending on the type of pipe material, the minimum depth of installation can be indicated, so as to avoid the failure of the pipes due to road traffic. From this perspective, similar studies could also be carried out regarding the negative influence of road traffic on sewerage networks, gas networks and heating networks.

Impact of Pipe Materials and Chlorination on Planktonic and Biofilm Cells of Listeria monocytogenes

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 (PP), polyethylene (PE), iron (I), copper (Cu) and rubber (R). Six samples of L. monocytogenes biofilm were collected from the previous designed system at three different biofilm ages (10, 40 and 90 days-old). The collected biofilm samples were exposed to different chlorine doses (0.2, 0.6, 1.0, 1.4, 1.8, 2.2, 2.6 and 3.0 mg/l) at 10 min, and then total bacterial counts using pour plate method was enumerated. The results showed that the log reduction of 90 days-old of L. monocytogenes biofilm formation, when exposed to 3.0 mg/l of chlorine dose, on six pipe

Computer analysis of the different water hammer protection systems

Water hammer is defined as a pressure surge or wave caused when a fluid in motion is forced to stop or change direction suddenly. This pressure wave can cause major problems to transmission pipes.. The present study aims to investigate problems resulting from unsteady flow and then investigate the effect of using a protection device; air vessel only, surge tank only and air vessel with surge tank; to protect pipelines against water hammer. Through this work, the study is applied using Water Hammer Software Wanda V3.30. In the present study for transient condition caused by pump failure, it is found that using the proposed an air vessel as a protection device proved to be effective for prevent column separation, using of air vessel with two surge towers will not effect the total volume of protection. Increases the diameter of the pipeline reduces the surge pressures and decrease the total volume required to protect the system. Otherwise, change of pipe material type from Glass Reinforced Plastic to steel decreases the minimum pressure but does not effect the total volume required to protect the system and change of pipe material type from Glass Reinforced Plastic to concrete decreases the minimum pressure and the total volume required to protect the system. Finally found that as the air vessel volume is reduced the number of used air vessels is increased and the negative pressure of the pipe line not affected.

Impact of weather conditions on pipe failure: a statistical analysis

The occurrence of pipe failures in drinking water distribution networks may be influenced by weather conditions. In this work, a statistical analysis is performed to study the correlations between weather parameters and pipe failure in the Netherlands with the ultimate aim to predict the effects of climate change on network integrity. Failure data from a Dutch national failure database were divided into different cohorts, depending on type of pipe material, year of installation, and diameter class. Weather data related to temperature, drought, and wind were collected. Relationships between weather data and failure data were sought using a linear regression analysis and a frequency analysis. The latter analysis results in a weather variable dependent pipe failure frequency. The most obvious relationships were found between pipe failure and temperature. Failures in asbestos-cement (AC) and steel pipes increased during warm periods, which often simultaneously occurred when water consumptions were high. For cast iron pipes, failures increased at low temperatures. Drought parameters had a smaller effect on pipe failure than temperature, but still an increase in pipe failure was observed during dry periods for AC and steel pipes. No effect of weather conditions on pipe failure were observed for poly(vinyl chloride) and polyethylene pipes.

Impact of elevated Ca2+/Mg2+ concentrations of reverse osmosis membrane desalinated seawater on the stability of water pipe materials

Hardness and alkalinity are known factors influencing the chemical stability of desalinated water. This study was carried out to investigate the effect of Ca(2+) and Mg(2+) on corrosion and/or scale formation on the surface of different water distribution pipe materials under tropical conditions. The corrosion rates of ductile iron, cast iron and cement-lined ductile iron coupons were examined in reverse osmosis (RO) membrane desalinated seawater which was remineralised using different concentrations of Ca(2+) and Mg(2+). The changes in water characteristics and the coupon corrosion rates were studied before and after the post-treatment. The corrosion mechanisms and corrosion products were examined using scanning electron microscope and X-ray diffraction, respectively. We found that the combination of Ca(2+) and Mg(2+) (60/40 mg/L as CaCO3) resulted in lower corrosion rates than all other treatments for the three types of pipe materials, suggesting that Ca(2+)/Mg(2+) combination improves the chemical stability of desalinated seawater rather than Ca(2+) only.