Ductile iron double flanged pipes are most suitable for over ground pipelines like portions of Pipelines on Pillars Pedestals for Rivers Canal or Road crossing and bridges. In these pipes the flanges are flat rings around the end of pipes which mate with an equivalent flange from another pipe, the two being held together by bolts usually passed through holes drilled through the flanges. A deformable gasket, usually electrometric, placed between raised faces on the mating flanges provides the seal. The predominant wall material is ductile iron, a spheroidized graphite cast iron, although an internal cement mortar lining usually serves to inhibit corrosion from the fluid being distributed, and various types of external coating are used to inhibit corrosion from the environment. Ductile iron pipe is a direct development of earlier cast iron pipe which it has superseded. Ductile iron has proven to be a better pipe material, being stronger and more fracture resistant; however, like most ferrous materials, it is susceptible to corrosion and retains some brittle characteristics. Relatively recent developments such as polyethylene sleeving andor zinc and polymer coatings have done much to mitigate corrosion concerns.

Ductile iron double flanged pipes are most suitable for over ground pipelines like portions of Pipelines on Pillars Pedestals for Rivers Canal or Road crossing and bridges. In these pipes the flanges are flat rings around the end of pipes which mate with an equivalent flange from another pipe, the two being held together by bolts usually passed through holes drilled through the flanges. A deformable gasket, usually electrometric, placed between raised faces on the mating flanges provides the seal. The predominant wall material is ductile iron, a spheroidized graphite cast iron, although an internal cement mortar lining usually serves to inhibit corrosion from the fluid being distributed, and various types of external coating are used to inhibit corrosion from the environment. Ductile iron pipe is a direct development of earlier cast iron pipe which it has superseded. Ductile iron has proven to be a better pipe material, being stronger and more fracture resistant; however, like most ferrous materials, it is susceptible to corrosion and retains some brittle characteristics. Relatively recent developments such as polyethylene sleeving andor zinc and polymer coatings have done much to mitigate corrosion concerns.