The invention relates to a connection piece for producing a liquid connection between liquid-conveying lines for mounting in a recess of a housing part of a medical appliance, in particular of a dialysis appliance. In addition, the invention relates to a medical appliance, in particular a dialysis appliance, with a housing having a housing part with a recess into which such a connection piece is inserted. The connection piece 13 according to the invention has a tubular body 18 which is made of an electrically conductive material and which can be inserted into the recess 23 of the housing part 1A and whose end pieces 19, 20 are configured for the attachment of the liquid-conveying lines. The connection piece 13 is characterized by an attachment part 16 for the attachment of an electrical protective conductor or potential equalization element, wherein the attachment part 16 is connectable or connected to the tubular body 18 in an electrically conductive manner. The attachment part 16 permits direct attachment of an electrical connector cable 17 to a protective conductor 15 (PE conductor).
