Solid Stainless Steel for MSK One Through Plants
“Previously published as part of The International Desalination Association (IDA) World Congress Proceedings, Madrid-Spain 1997”
Abstract: A field test in a Multi Stage Flash (MSF) once through plant has been evaluated. Six metallic construction materials, five stainless steels and one nickel base alloy, were exposed for a period of five months in the hot chlorinated and air saturated sea water stream which enters the first flash chamber at a temperature of 100°C. The lowest alloyed grades, I.e. type 316 and 317LMN, suffered crevice corrosion while the highly alloyed grades 254 SMO® and 654 SMO® were resistant. Also the duplex grade 2205 was resistant to corrosion. No material suffered pitting or stress corrosion cracking.
The uniform corrosion rate, 1.e. the type of corrosion decisive for the general mass loss, is extremely low, releasing less than 0.5 kg of stainless steel per 1,000 m² (~10,000 sq.ft) exposed area annually.
A 6Mo grade such as 254 SMO is a good choice for the first stage of evaporator vessels if solid stainless steel is being used. The first six stages of the plant where the test was performed are made of solid 254 SMO.
The test will continue to enable a second evaluation after approximately one year of exposure.
For more information please refer to the International Desalination website.