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Construction of Sewers
Published in Subhash Verma, Varinder S. Kanwar, Siby John, Environmental Engineering, 2022
Subhash Verma, Varinder S. Kanwar, Siby John
Cast iron (CI) pipe is available from 100 mm to 1200 mm in diameter with a variety of jointing methods. They are used in gravity sewers where tight joints are essential. The advantages of cast iron pipe are long laying lengths with tight joints, its ability to withstand high internal pressure and external load, and its corrosion resistance in most natural soils. They are very vulnerable to corrosion unless protected by lining with paint or cement concrete. They are relatively costly and used under special circumstances such as heavy external loads, protection against contamination, crossing low-level areas, the prevalence of wet conditions, and temperature variations and vibrations. When specifying cast iron pipe, it is necessary to give the pipe class, the joint type, the type of lining and the type of exterior coating.
Infrastructure and the Need for Condition Assessment
Published in Justin Starr, Water and Wastewater Pipeline Assessment Technologies, 2021
Cast iron pipes can be attacked externally as well – mostly through acidic soils (Figure 1.10). Damage to the pipe can result in significant water loss in a short period of time. When pipes are installed under roads, this can cause rapid washout of soil and the formation of a sinkhole. That said, cast iron remains a critical part of American infrastructure. Municipal Sewer and Water Magazine noted that in 2014, more than 600 municipalities had at least one cast iron pipe in service that was more than 100 years old. More than 20 systems had segments that were more than 150 years old.
The design of water transport and distribution systems
Published in Nemanja Trifunović, Introduction to Urban Water Distribution, 2020
Cast iron is one of the oldest pipe materials used for the conveyance of water under pressure. However, the use of cast iron pipes has declined over the last few decades. Nevertheless, it is not uncommon to come across a cast iron pipe that is over 100 years old and still in good condition; considerable lengths exist in some networks even in developed countries, such as in the UK or USA. Two examples of old CI pipes shown in Figure 4.35 are from the Netherlands. These pipes have been well preserved even without much protection, owing to the continuous supply and absence of external corrosion, which was not the case with the pipes in Figure 4.36 originating from former Eastern Germany in the water distribution systems with intermittent supply and inadequate water composition. Cast iron pipes
Reliability based failure assessment of deteriorated cast iron pipes lined with polymeric liners
Published in Structure and Infrastructure Engineering, 2023
Guoyang Fu, Benjamin Shannon, Rukshan Azoor, Jian Ji, Ravin Deo, Jayantha Kodikara
This paper presented a probabilistic analysis of deteriorated cast iron pipes lined with polymeric liners, given the uncertainties of key physical parameters in the failure criteria of lined pipes. A field validated corrosion model was used for cast iron pipes while new tensile creep and creep rupture models developed for spray and CIPP liners at Monash University were utilized in this study. Various failure modes of lined pipes were considered by classifying cast iron pipes as fully and partially deteriorated and the first order reliability method was employed to conduct the probabilistic analysis. Two worked examples were demonstrated for probabilistic analysis, one for a fully deteriorated cast iron pipe and the other for a partially deteriorated cast iron pipe, followed by a sensitivity analysis.
A model of stress concentration factors for external corrosion patches on large-diameter underground cast iron pipes
Published in Sustainable and Resilient Infrastructure, 2023
Guoyang Fu, Chunshun Zhang, Ravin Deo, Suranji Rathnayaka, Benjamin Shannon, Jayantha Kodikara
In this study, the finite element software ABAQUS (2013) was used to conduct stress analysis. Experimental tests of cast iron coupons under tension or compression generally show a nonlinear stress-strain curve (Johnson, 1890; Makar & McDonald, 2007; Rajani, 2012; Shawki & Naga, 1986). However, in this study cast iron was assumed to be linear elastic with a Young’s modulus of 100 GPa and a Poisson’s ratio of 0.3. This assumption is reasonable due to the low operating pressure in water pipes, which is usually less than 1 MPa. A comparison between the results from models with non-linear material and linear elastic material showed that the latter can overestimate the maximum stress by up to 30% (Ji et al., 2015). The overestimation of maximum stresses by the assumption of linear elastic cast iron is considered conservative for engineering applications. The soil was considered to be linear elastic with a Young’s modulus of 50 MPa and a Poisson’s ratio of 0.3. It should be noted that under same loading conditions and with same burial depth, pipes buried in soil with high modulus in general experience smaller stress compared with those in soil with low modulus. The interface between the soil and the cast iron pipe was assumed frictionless.
Micro-hydropower in drinking water gravity pipelines: a case study in Uttarakhand, India
Published in ISH Journal of Hydraulic Engineering, 2020
Epari Ritesh Patro, Thomas J. Voltz, Arun Kumar, Thomas Grischek
This assumes only the minimum necessary expansion, such that the values for power yield computed in Table 8 represent the minimum that would be available. If a pipeline with an even larger diameter is chosen with hydropower development in mind, as would certainly happen in the case of an expansion to meet rising demand, the power yield would be even greater. Based on the calculations for the hypothetical retrofit case, these MHP projects as accompaniments to a planned pipeline expansion would almost certainly be economically viable. Since the costs incurred by the new pipeline would have resulted anyway, only the additional cost of increasing the pipeline diameter to enable MHP is relevant for the economic viability of the MHP turbine infrastructure. For example, based on current prices in Uttarakhand, the cost of 200 mm galvanized iron pipe is 1650 Rs./meter compared to 1080 Rs./meter for 150-mm cast iron pipe. This means there will only be an additional 53% added to the investment to enable MHP.