Investigation of water absorption profile of mineral wool insulation

This study is targeted at investigating the water absorption capacity of mineral wool insulation in order to understand its behaviour and contribution towards the occurrence of corrosion under insulation in industries. Corrosion of insulated process facilities is either triggered by the penetration of water from the immediate external environment or condensation of water within the internal domains of insulated assets. The degree of penetration of water from the external environment to the surface of insulated process facilities reflects the performance of the insulation material. Therefore, it is essential to investigate the water absorption profile of mineral wool insulation under different conditions such as: change in pH and temperature in order to ascertain its performance when insulated on a substrate. This was conducted according to ASTM C1511 standard. Preliminary results revealed a rapid increase in water absorption up to 40 % within the first fifteen minutes indicating susceptibility to the absorption of water, which increases with pH. However, this absorption reduced significantly when the material was subjected to varying temperatures from 50-250 oC reflecting its behaviour when insulated on a hot substrate. Also, the presence of aluminium foil as a barrier in mineral wool was observed to significantly reduce the overall water absorption capacity indicating additional protection. However, should water penetrate the insulation, it will take a longer time for it to dry out when the foil is in place when compared to the absence of foil.