Insulating joints are used for the electrical separation of pipeline systems or for dividing pipelines that are affected by high voltages into sections. The electrical isolation of cathodically protected systems is maintained until the dielectric strength/ flashover strength of the insulating joint is reached. Overvoltages which occur as a result of lightning striking exposed parts of a pipeline system can exceed t he dielectric strength of insulating joints. This can result in open sparks or destruct ion of the insulating joint.

Ex isolating spark gaps (ExFS) with suitable connect ion technology have the task of protecting the insulating joint (insulation) against lightning-induced overvoltages and discharging the lightning energy without sparking when dealing with dangerous explosive atmospheres (d.e.A.) at t he same time. During normal operation and after the discharge process, the ExFS should disconnect safely electrically. In addition to checking ExFS, GW 24 [1] also provides information on the sel ection of ExFS including the suitabl e connection technology, which is described in more detail below.