Troubleshooting Challenge: Drill Rig’s Top Drive Drops Uncontrollably (.PDF Download)

A 65-ft.-high drill rig, mounted on a freshwater barge, was allowing its top drive head to drop uncontrollably. The circuit controlling this function shows (see illustration) both a brake (counterbalance) valve and a hydraulically controlled mechanical brake on the hoist function. The systems’ power unit was mounted close to the deck, with its A and B line hoses going up to top drive’s hydraulic motor. The brake and shuttle valve were plumbed close to th

Register to view the full article

By registering on Hydraulics & Pneumatics now, you'll not only gain access to [current-page-title], you'll also receive a complimentary copy of Hydraulics & Pneumatics 2016 Salary & Career Report.