FOAMGLAS INSULATION FOR BURIED HOT PIPES

preliminary investigation has disclosed that Foamglas was being used successfully by a number of organizations to protect pipes in dry soild. A more extensive investigation, which included examination of Foamglas-insulated pipes in situ and examination of samples of soils and Foamglas, disclosed 1 the vapor barrier on the Foamglas was frequently broken, allowing moisture to penetrate the Foamglas insulation, 2 Foamglas absorbs more water as much as 7.9 by colume than had been reported, and 3 failure of vapor barrier and insulating material to prevent water intrusion permitted pipe corrosion, heat loss, and sometimes disintegration of the Foamglas. On the basis of these investigations it was concluded that Foamglass is not suitable for insulating pipes below the water table or in wet soils.