Gas insulated electrical apparatus with particle traps

A gas insulated electrical apparatus comprising:

• a hermetic sheath having a plurality of electrically conductive sheath sections each including flanged ends;
• a high voltage conductor disposed within said sheath;
• an electrically insulating spacer for electrically insulatably supporting said conductor relative to said sheath, said spacer having an outer circular periphery of a diameter which is substantially the same as the diameter of said flanged ends of said sheath sections;
• a pair of electrically conductive trap rings interposed between adjacent flanged ends of said sheath sections and said outer periphery of said spacer, each said trap ring defining, between each said trap ring and said spacer, a low electric field particle trap in which electrically conductive particles can be retained;
• through hole fastening means for fastening said flanged ends of said sheath sections, a portion of each of said trap rings and said outer periphery of said spacer thereof;
• an electrically insulating gas disposed within said sheath;
• and
• an inner periphery of each of said trap rings having a substantially rounded cross-section to moderate the concentration of the electric field.