Electrically insulated joint for metal pipes

An electrically insulated joint for metal piping, comprising:

• two receiving elements each having an opposing surface facing each other, at least one of said opposing surfaces having a projecting portion and a recessed portion recessed relative to said projecting portion, said recessed portion having an outer diameter smaller than an outer diameter of said projecting portion;
• an insulating ring composed of a metallic element having an outer surface and an insulation member of high compression strength lining the whole outer surface of and adhering to said metallic element so as to make said insulating ring impermeable to gas and liquid, said metallic element including a metal ring and at least one leg integral with and extending radially from said metal ring so as to provide said insulating ring with an outermost diameter, said recessed portion extending in a radial direction along all of said leg;
• an elastic sealing ring having an inner diameter in a non-compressed state smaller than said outermost diameter of said insulating ring, said leg having an inner surface facing said elastic sealing ring, said inner surface lying substantially in one common plane with said projecting portion, said insulation member on said leg being disposed against said recessed portion, said two receiving elements being pressed together so as to compress said insulating ring and said elastic sealing ring between said opposing surfaces and thereby insulate said opposing surfaces of said two receiving elements;
• and
• means for pressing said two receiving elements together.