Protective coating corrosion failure is a complicated process that involves various phenomena which are hard to test for separately. An adequately protected pipe can be in service for a relatively long time without exhibiting any signs of corrosion failure, and then all of a sudden it corrodes over a short period of time. Failure will definitely happen if the interface between the pipe surface ...

N. Rastkhah, K. Edalati, A. Kermani, M. Seiedi, A. Movafeghi Safety and Radiation Protection Technological Center, Iranian Nuclear Regulatory Authority, Atomic Energy Organization of Iran, Northern Kargar Ave., Tehran, Iran Abstract: This study is a new attempt followed the research project conducted by IAEA in a Contract Research Project (CRP). In this new challenge, the reference blocks desig...

In order to monitor the pipe thinning caused by flow-accelerated corrosion (FAC) that occurs in coolant piping systems, a shear horizontal ultrasonic pitch-catch waveguide technique was developed for accurate pipe wall thickness monitoring. A clamping device for dry coupling contact between the end of the waveguide and pipe surface was designed and fabricated. A computer program for multichanne...

Ductile iron replaced grey cast iron as pipe material in the early 1970s. It has been estimated that almost half of all new water mains in North America are ductile iron. The main cause of the structural deterioration of all metallic mains is external corrosion, which is induced by environmental and operational conditions. Internal corrosion, on the other hand, can cause significant functional ...

Failures in the water distribution network are some most important factors in water losses, water shortage and dissatisfaction of users and secondary pollutions as well. This research aimed to analyze failure in water distribution networks during 2006-2008, for better water management. Daily failure reports in Ahvaz, Iran distribution network during 2006-2008, were collected from emergency depa...

The effects of disinfection and biofilm on the corrosion of cast iron pipe in a model reclaimed water distribution system were studied using annular reactors (ARs). The corrosion scales formed under different conditions were characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM), while the bacterial characteristics of biofilm on th...

A biofilm is a collection of organic and inorganic, living and dead material collected on a surface. It may be a complete film, or, more commonly in water systems, it is a small patch on a pipe surface. Biofilms in drinking-water pipe networks can be responsible for a wide range of water quality and operational problems. Biofilms contribute to loss of distribution system disinfectant residuals,...

The root cause of odor and corrosion in collection systems is sulfide, which is produced from sulfate by bacteria residing in a slime layer on the submerged portion of sewer pipes and structures. Once released from the wastewater as hydrogen sulfide gas, odor and corrosion problems begin. Another type of bacteria utilizes hydrogen sulfide gas to produce sulfuric acid that causes the destruction...

The remote field effect is an electromagnetic method for inspecting pipes and tubing. It has recently been commercialised as a technique for inspecting gray cast iron and ductile iron water mains. However, commercial tools provide information on pits depths in the pipe and overall wall loss. Models of the mechanical behaviour of cast iron pipe also require information on pit width and length. T...

This study establishes the ability of hydrate formation to initiate internal corrosions along natural gas pipelines. The identified corrosion types, which are cavitations, erosion and corrosions by chemical reactions, are capable to individually or collectively initiate pitting and stress cracking corrosions which are also dangerous to gas pipelines. The impacts of these corrosion types are cla...