Commercial gas piping repair. Replaced 3/4” stainless gas flexible piping to a tube heater in the service garage. There was a leak coming from the old flex. I used a radius turn when connecting the flex line with no hard turns or kinks recommended by the manufacturer. Turned on the gas, and no more leak. Also, there was a gas leak for the dryer on a fitting coming directly out of the gas regulator. I pulled apart all fittings, re-doped the fittings, taped everything, and installed a new gas 1/2” gas whip for the appliance. Turned on the gas, and no more leaks.