TIP: How to repair a backhoe damaged underground section of rigid conduit without union fittings.
First remove all conductors.
Use reciprocating saw to remove damaged section of pipe. Clean the burrs off ends of existing conduits to be mated by reaming with a half-moon or round file depending on size of pipe. Clean off any rust or debris the entire length of at least an inch and a half or two inches from the end of the conduits.
If conduit section removed was bent as damage, the remaining ends cut to be mated should now be able to accommodate a new straight section of pipe or at the least a light bend or kick in the new section if needed.
Cut your section of pipe to install to size after you have made any necessary bends. Make the space tolerance between the existing pipe ends and new pipe ends as small as possible. This will insure the best fit for a properly positioned coupling. If the length of rigid pipe to install is less than 10 feet you will need two appropriate sized threadless compression couplings for rigid conduit.
Midway inside the threadless compression coupling is a “pipe stop” or ridge. You need to remove these on both couplings. This will allow the full length of the coupling to move freely on the conduit. A half-moon or round file works good to remove these stops. Remove the compression rings and nuts before you do any filing.
Slide both couplings on the pipe to be installed. Install new section of pipe by sliding the coupling into place on existing conduit end. Make sure that you center the couplings between the ends of pipe so that the compression rings on both ends of coupling will clinch the pipes completely. If you do not center the coupling properly you could have a compression ring clinching partially the conduit end and partially the dead space between the conduits. This would be a bad installation.
Tighten up all connections. As an added benefit to installation, install black vinyl 10 Mil tape over the coupling and the length of the pipe.
Install new conductors.