[LazyPup]

First of all, let us define the term "PSIG"

We must remember that the earths atmosphere exerts an average pressure of 14.2pounds per square inch at sea level therefore if we used PSIA(pounds per square inch-Absolute) the guage would read all available pressure therefore even when totally disconnected and lying loose in your hand a PSIA guage would read the atmospheric pressure and indicate 14-15psi. We would then need to subtract the atmospheric pressure from the actual reading to determine the line pressure.

The term PSIG (Pounds per square inch-Guage) indicates that the guage measures pressure above standard atmospheric pressure or in simple terms, the guage is calibrated to read "zero" at standard atmospheric pressure and it indicates the pressure increase above standard atmosphere.

By contrast a vacuum guage reads pressure below standard atmospheric pressure and is usually calibrated in inches of mercury "in/hg".

Although seldom seen in plumbing, in the refrigeration trade they use a "coumpound guage" which is an absolute guage that is calibrated to read ZERO at standard atmospheric pressure, PSI at pressures above standard atmosphere and inches of mercury at pressures below standard atmosphere.

A residential gas meter contains an internal pressure reducing valve. In most jurisdictions the maximum allowable service pressure on the outlet or structure side of the meter is .5PSIG (8oz per square inch). In some areas that have older meters the limit is .25psig (4oz) line pressure.

You gas meter is listed for a maximum "10psig inlet pressure". This means that your meter may only be connected to a municipal main that has a working pressure of 10psig or less. Your meter would then receive gas from the municipal main at up to 10psig and reduce the line pressure to the code maximum of .25 or .5 psig before delivering it to your house.

Absolutely do not make any attempt to tie into the line before that regulator. It would result in delivering gas into your system at 10 /.25 = 40 times the allowable working pressure for the regulators on your appliances. Not only would that be illegal it would be potentially lethal because an ordinary kitchen range burner would now blow a flame 5 or 6 feet high not to mention what would happen in your furnace or water heater.

Due to the extremely low working pressure on residential gas lines line sizing requires very precise calculations. Before you can connect a gas range you must first determine if your existing gas line is capable of assuming the additional load. In order to determine the total load we would need to have a list of:
1. all appliances operated by gas, as well as the BTU/hr rating of the burners.
2.BTU/Hr per cubic foot value of your gas. (typically 1100btu/cu.ft)-check with local supplier.
3. For a manifold system we would need the total developed length of the pipe run from the manifold to the proposed range location.
4. Outlet pressure of your gas valve.
5. Diameter of the line from the gas valve to the manifold.
6. Working diameter of the manifold.

In addition to the calculations there are a number of very subtle nuances in the Gas Code such as type of materials, types of valves and fittings, type of joints permitted by location (I.E. Concealed vs. immediately accessible), placement of valves, unions and drip stubs etc.

When all things are considered running gas lines is not difficult but due to the complexities involved and the potential for disasster it is not a project that I would recommend to anyone who has not had prior experience under the direct supervision of someone certified in the trade.