Manually operated pincer mechanism for rapid shutoff of a pipeline that has developed a break or leak. The pincer mechanism is actuated by a manually operated hydraulic jack. The jaws are designed to shutoff small diameter steel pipe with the lower jaw in the upper position and with adapter members attached to both jaws with the lower jaw in the lower position is able to squeeze off plastic pipe up to a larger specified diameter. Removal of the plastic adapter jaws and with the lower jaw in the lower position permits booming down on patches for steel pipe up to a larger specified diameter for welding.
