a mounting system for a fill - up and circulating tool on the rig hoisting system is disclosed . in the preferred embodiment , the tool is supported on one of the bails and it driven to rotate around the longitudinal axis of one of the bails . a combined vertical and rotational movement is imparted by the mounting system to allow the fill - up and circulating tool to be raised and swung out from between the bails to allow normal drilling or tripping . in the other position it can be swung over the tubular and lowered for sealing contact to allow fluids to pass in both directions to or from a pumping and storage system on the rig .