Girard spheres are manufactured in a range of durometers for meter prover and pipeline applications. The GSY (yellow) is designed for meter prover use and the GSG (green) and GSR (red) are designed for pipeline use. Girard spheres are
available in sizes from 2" to 36".
Maximum benefits are obtained when spheres are properly filled and sized. Specific applications will determine the most effective sizing and filler fluid to be used. In general, Girard spheres should be sized 1% larger than pipe ID. Information on recommended use is available from Corrosion Control Products Company.