Ball-Operated Emergency Disconnect An emergency disconnect should be in the tool string to use in the event that the running tool does not operate properly. This could be either a pull disconnect (wireline applications) or a hydraulic disconnect. The hydraulic disconnect (pipe applications) is operated by pumping a ball to the tool and applying pressure. The pull disconnect is operated by pull. When running a bridge plug in on wireline a Belleville spring type pull disconnect should be used.