IEEE Standards IEEE C37.122.7-2021 pdf free download – IEEE Guide for Field Testng of Gas-Insulated Substatons Rated Above 52 kV IEEE C37.122.7-2021 pdf free download - IEEE Guide for Field Testng of Gas-Insulated Substatons Rated Above 52 kV. .2.2 Gas leakage tests 4.2.2.1 Vacuum rise test Prior to the gas leak test, a vacuum rise test will... 02-24 Download Now