English to Serbian Tech/Engineering Metallurgy / Casting ductile iron pipes

One of the main defects in ductile iron pipes are surface defects, such as pinholes. Pinholes are typically holes located in the external surface of pipes, and are generally undesirable in cast products as they may compromise the structural integrity of the cast products. In cast iron pipes pinhole defects can generate water leaking when the pipes are connected with water pressure