PERFORMANCE OF NODULAR CAST IRON AS VALVE MATERIAL IN ARABIAN GULF SEAWATER

Abstract

Failure analysis was conducted on three modular cast-iron globe valves of different sizes used in flowing seawater cooling systems. The 3-in. valve suffered from cavitation corrosion and erosion cracks. In the larger valves, intensified localised attack was found under voluminous scales. In all valves, galvanic corrosion was evident in areas of the body under the stainless-steel seat rings. The results are substantiated by investigating the corrosion behaviour of cat iron in stagnant and flowing seawater.