LOAD COMPENSATOR FOR A PIPE RUNNING TOOL

摘要

A load compensator (304) is disclosed for use in connection with a pipe running tool (10). The load compensator (304) includes an outer housing (308) connected to the portion of the pipe running tool (10) that holds the pipe segment. A piston (310) is disposed within the housing (308), and is connected to a top drive system of the pipe running tool (10). The housing (308) is formed with a first port (312) through which pressurized air is delivered inside the housing (308) to drive the piston (310) within the housing (308). A second port (314) is disposed at a selected location on the housing (308), such that when the piston (310) is advanced past the second port (314), pressurized air passes through the port (314), and causes the control circuit (306) to stop delivering air through the first port (312). Once pressurized air no longer flows through the second port (314), the control circuit (306) causes air to be delivered to the first port (312).