Cast irons ductile iron

Cast Iron, Ductile Iron, and High-Silicon Iron. 10-92... 

CAST IRON, DUCTILE IRON, AND HIGH-SILICON IRON... 

Major internal corrosion can occur in pipes made of cast iron, ductile iron, steel, galvanized steel, and cement-based materials. Table 3.3 summarizes the types of corrosion occurring in different piping materials and the possible tap water quality problems caused by them, as described by the AWWA Research Foundation in 1996 in a reference book on internal corrosion of water distribution systems (17). 

Water is pumped from temporary storage tanks or from the treatment facilities through large-diameter transmission water pipes. The transmission water piping system contains large valves where the water amounts are measured using water meters. The materials of construction of transmission pipe are cast iron, ductile iron, prestressed concrete, asbestos concrete, PVC and welded steel piping. All of these materials except PVC contain ferrous metal components, which need corrosion protection. The different materials used in transmission are as shown in Table 4.31. 

The water mains used to distribute drinking water have normally been constructed from cast-iron, ductile iron, asbestos cement and, more recently, from plastics (for example, MDPE medium density polyethylene). Leaching of lead from these materials does not normally occur. Very exceptionally, lead water mains have been used to distribute drinking water. The only known occurrences are in Ireland where their replacement has high priority (Devaney, 2009). 

Iron (cast iron, ductile iron, malleable iron) AC AC or DCEN... 

Cast iron, ductile iron, or steel pipe may be coated at the mill by a process during which the pipe is spun on the center of its longitudinal axis while a mortar mixture is sprayed onto the inside surface in a uniform, dense layer. After proper curing, provided the pipe is handled carefully, this coating can protect the pipe interior against attack by water and many other liquid and gaseous corrosive environments. 

Ductile cast iron Ductile irons (aU grades)... 

Other Types of Piping Joints Packed-gland joints (Fig. 10-135) require no special end preparation of pipe but do reqmre careful control of the diameter of the pipe. Thus the suppher of the pipe shoiild be notified when packed-gland joints are to be used. Cast- and ductile-iron pipe, fittings, and valves are available with the bell cast on one or... 

Cast irons are iron with high levels of carbon. Heat treatments and alloying element additions produce gray cast iron, malleable iron, ductile iron, spheroidal cast iron and other grades. The mechanical properties vary significantly. Nickel-containing cast irons have improved hardness and corrosion resistance. Copper or molybdenum additions improve strength. 

Valves having shell (body, bonnet, cover, and /or end flange) components made of cast or ductile iron shall not be used in hydrogen service. 

Deterioration of water pipe fittings such as service saddles contributes to water main failures. This type of failure may be due to galvanic corrosion since the pipe is cast or ductile iron, saddle is either bronze, steel or cast iron and the service line is made of copper. 

Chemical and physical analysis of the soils where the failures of pipe were observed showed the soils to be either corrosive or very corrosive. The soils consisted of wet salty clay containing irons with resistivity in the range of 820 1200 Ocm. A strong relationship between the corrosion rate of buried cast and ductile iron pipes and soil resistivity was found. 

Cast and ductile iron Uniform Pitting MIC Concentration cell... 

Staples, L. B., A New Tool for Condition Evaluation of Cast and Ductile Iron Pipe." Corrosion/96, Paper 45, NACE International, Houston, TX, 1996. 

A fatal accident and some other disasters, which were caused by small cracks, lead to a more strict consideration of the security of these steam drums. Parallel to these the economical pressure, due to the globalisation of the today s industry, lead to the increase of the pressure and the rotation speed of the paper production machines for a higher output of the production, which means, that all safety aspects from the design and the material will be exploited totally. On the other hand cast iron is also not a ductile and comfortable material, like the most steels for the pressure equipment. 

This study detects the defect of the void and the exfoliation in the solid phase diffusion bonding interface of ductile cast iron and stainless steel with a nickel insert metal using ultrrasonic testing method, and examine the influence of mutual interference of the reflectional wave both the defect and the interface. 

---