CATIONIC CHEMICALS IN STEAM PLANT: Filming Amines Prevent Condensate Line Corrosion

Abstract

The advantages of reclaiming as much condensate as possible in any steam‐generating system are manifest. The return of hot water to the boiler results in a considerable reduction in fuel and water consumption. In addition, a low make‐up will give rise to a lower rate of corrosion attack due to carbon dioxide generated from dissolved bicarbonates. However, such a procedure greatly increases the length of piping and number of fittings which are exposed to attack. The corrosion of steam and condensate return lines, and also of steam‐using equipment, can become a major problem. Perforation of steam jackets, steam coils, pipes and fittings; choking of steam traps with corrosion products; leaking valves and joints are serious enough in themselves. The cost of replacing the corroded equipment is often considerable and excessive damage may be caused by the ingress of steam or water to the product being manufactured. In addition, a very high labour cost is often involved. Repairs to damaged plant must usually take place at weekends and during holiday time, when overtime rates are paid.