4 to 8 oz. Natural gas entering the building is reduced to 10" water column by the regulator on the gas meter, and is further reduced to 3.5" w.c. by the individual appliances. The size ( in this case you mentioned 1/2 inch ) does not matter. What does matter is the design, installation, and testing. The gas purveyor can provide regulators at the meter that reduce the pressure entering the structure to 1/2 pound, 2 pounds, and 5 pounds, that I know of. Other pressures might be available. The system would have to be installed, tested, and inspected at the test pressures required by the administrative authority. It would also have to meet any other code requirements, such as type of material (pipe and fittings), type of joint for the installed size (welded, threaded, etc.), hangers (and spacing of), isolation, etc. Here in Oregon we are required to test a gas system at 30 times the regulator setting. Therefore a 1/2 pound system is tested at 15#, a 2 pound system is tested at 60 pounds, and so on. The advantage to piping a structure with a higher pressure system is that pipe sizing can be correspondingly lower, especially beneficial in long runs in commercial structures. The drawback is, if a pressure above 1/2 pound is used, an additional pressure regulator is necessary at each appliance. You also need to consider the cubic feet per minute so you can establish pipe sizing. even at higher pressure for some appliances especially furnaces you might possibly run a one inch or larger pipe if you have other gas appliances in your building.
Low pressure - 6 to 7 inches water column, equivalent to 4 ounces or 1/4 PSI, is the standard pressure supplied by natural gas utilities in the USA and Canada. Check with your local utility if you need to increase the pressure for your use. Most natural gas appliances manufactured for use in the US are designed to operate up to a maximum of 14 inches water column.
Very safe.
natural gas
medium pressure
The gas orfice when operating creates a vacuum drawing combustion air into the burner. This is the reason that gas pressures vary between types. Natural gas appliances operate at a nominal 3.5" wc pressure, while LP appliances run 10-11" wc. Natural gas has about 1000 btu's per cubic foot, while LP gas has about 2500. As an example, if you were to reduce the manifold pressure of LPG, you would have an oxygen starved mixture that would not burn properly. lc
One can usually find both gas (natural as well as propane) and electric appliances at most, if not all, appliance stores. Stores such as Sears and Best Buy sell appliances, including gas, as well.
700 km
Without knowing whether this is atmospheric-pressure natural gas, pipeline-pressure or compressed natural gas (and the pressure it's been compressed to), or liquefied natural gas, this is an unanswerable question.
The Natural frequency is the frequency at which Resonance(maximum amplitude) occurs.
The incoming pressure of natural gas in the UK is somewhere between 19-23 mbar.
In natural frequencies the output of the system will be less than the maximum level. In the resonance frequency the output of the system will be the maximum level.
In Denver the atmospheric pressure is approx 12.1 psi. As you go up in elevation this will drop. Even going up a mere 500' will change it. I had to learn all the de rated values for the surrounding areas for natural gas in appliances. Delivery pressures and orifice sizing will change or you will have under or over firing.