Deaerated membranes are used to prevent rusting of metal pipes used for boiler water, tap water in buildings and apartments, and gray water. Water pipes in buildings and condominiums are embedded in walls for aesthetic reasons, but after about 10 years, red water appears, and in another 10 years, the pipes got clogged with rust, requiring labour to replace them. The cause of this problem is the oxidative corrosion of water pipes due to dissolved oxygen, and as a countermeasure, a dissolved oxygen removal device using a degassing membrane is used.
The rust-preventing effect of deaeration of pipes to a dissolved oxygen concentration of 0.5 ppm or less has been shown to increase the life of pipes by 4.5 times, and for pipes with a remaining life of 6 years, the life is extended to 6 years x 4.5 times = 27 years.
