Stainless steels are widely used for pool ladders, wave machine grilles, handrails and diving board structures as well as in environmental engineering plant. When correctly selected, designed, fabricated and operated, they give generally good performance. However, there have been some instances of corrosion as a result of the particular atmospheric circumstances which can arise in indoor swimming pool buildings.
Grade selection
For the following items:
types 304 and 316 are widely used and have given excellent service when properly maintained. Type 316 is strongly preferred for its greater resistance to staining, pitting and crevice corrosion in the majority of pool conditions
Components which are in the pool hall atmosphere, which are safety-critical and load-bearing but which are not washed or cleaned frequently, are potentially vulnerable to stress corrosion cracking (SCC). Examples are:
Types 304 and 316 have been found to be susceptible to SCC in laboratory tests and in some swimming pool atmospheres, and must not be used for components vulnerable to SCC if failure could result in personal injury. More highly alloyed grades of austenitic stainless steel have a much greater degree of SCC resistance. The currently recommended grades for these applications include:
Alternative high alloy stainless steels are under review.
Highly aggressive conditions can be found in some areas of the ventilation and water treatment plant. Specific advice on material selection should be sought.
Design
The following guidelines should be followed to achieve good performance:
Maintenance and inspection
Good design will minimise the burden of maintenance. All stainless steel items around the pool should be washed down daily. Other stainless items should be cleaned by wiping once a week where practicable. Brown staining of stainless steel items is an indication of either an inadequate cleaning regime or an aggressive pool hall atmosphere. Carbon steel brushes or carbon steel wire wool should never be used on stainless steel. Chemical cleaners must be compatible with stainless steel.
The inspection procedures should be such that the safety can be guaranteed of structures which rely on stainless steel items subject to corrosion.