BYPASS VALVE AND PIG HAVING A BYPASS VALVE

摘要

A bypass valve for an inspection and/or cleaning pig which is intended to move through a pipeline through which medium flows. The bypass valve comprises an inner space which is provided with a flow profile and in which there is arranged a piston which can be moved in the longitudinal direction of the bypass valve by means of a force storage medium in a pressure-dependent manner. The piston can also be moved between a first open position of the bypass valve which enables a bypass for the medium and a second position which at least substantially closes the bypass. The piston can be further moved from the first position via the second position in the same direction into a maximum position which opens the bypass again and pig for inspection and/or cleaning of pipelines.