What is a safe pH range?
There is no safe pH range. Other factors must be considered. For example, in the area of external corrosion, soils with a pH of 0.0 to 4.0 are acidic and serve well as a corrosive electrolyte. Soils with a pH of 8.5 to 14.0 are generally high in dissolved salts, yielding a corrosive soil with low resistivity. Soils with a near neutral pH of 6.5 to 7.5 and low redox conditions are optimum for sulfate reduction by bacteria, which can cause corrosion. In terms of the pH range of effluents inside the pipe, chemicals with a broad range of pH’s can attack iron, cement lining, asphalt sealcoat, and/or rubber gaskets. In addition to pH, factors such as the specific chemical or chemicals being conveyed, concentration, temperature, flow rate, etc. are needed to determine the suitability of the pipe, lining, and gasket materials for a specific type of service.
