One thing that MUST not be done is to install a bonding jumper around a gas meter. Gas meters almost always have a dielectric union on the custormer side of the meter. Metal gas pipes have a negative direct current voltage on them for corrosion protection. The reason why underground gas pipes are insulated is to conserve corrosion protection current and to concentrate the voltage gradient at the suface of the pipe so that it does the most good.
Similarly, plastic underground gas pipes have an insulated tracer wire. This wire also has a corrosion protection voltage on it.
In both cases of metallic pipes and tracer wires the ability to place and audio tone current over the metal needs to be possible so that gas lines can be located. A few months ago a gas company technician was having a devil of a time across the street from us because someone who had patched some metal gas pipeline with plastic pipe had NOT hooked up the tracer wires so that the connection was electrically sound and chemically durable.
Mike Cole, mc5w at earthlink dot net
Michael R.Cole September 5 2006, 10:13 am EDT
