Fuel Transfer Pumps

[CircleJAcres]

Keep having a problem with the fuel transfer pumps working loose on my tank in the bed of the truck..  They are the old Gas Boys with the lock down bolt.  The bolt rubs a groove in the pipe stand and the pump then spins around the pipe.  Certainly cant weld it still. 

Any suggestions

[siloguy]

Is the lock down bolt just a setscrew that tightens against the pipe? You could mark the spot where it is supposed to bite into the pipe, then drill into the pipe a bit so the setscrew has something to pilot into.  You may have better luck using a longer set screw with a jam nut to keep it tight.