Model M Manual : Appendix
Nitrogen Information (N2)
Nitrogen comprises approximately 79% by volume of the air. It is found
chemically combined in many forms in nature. Nitrogen will not burn and
will not support combustion. Nitrogen is normally available in cylinders
compressed to 2200-psi.
Nitrogen is used as an inert gas in electrical systems, the chemical
industry, and in the food packaging industry. Nitrogen, also finds
extensive use as an inert atmosphere and in the filling of some
incandescent lamps.
Nitrogen is nontoxic but can asphyxiate human beings and animal life by
displacing the necessary amount of oxygen in the air to sustain life.
ACOUSTIC LIQUID LEVEL DEPTH MEASUREMENT CONSIDERATIONS
Generally, a pressure regulator should be used with N2 since the
initial cylinder pressure is 2200-psi, which is normally in excess of the
wellhead pressure rating or the maximum rating of some of the pressure
gauges.
During pressure buildup testing, the pressure regulator should be set
so that the pressure in the volume chamber will exceed the pressure on the
casing annulus when the operator returns to check the equipment. Less gas
will be used if the pressure regulator is set to a lower value.
HANDLING PRECAUTIONS
Never drop cylinders or permit them to strike each other violently.
Never tamper with safety devices in valves or cylinders. See your local
gas supply dealer for other precautions.
| PHYSICAL CONSTANTS |
| Molecular Weight |
28.016 |
| Density @ 70°F, 1-atm |
0.17247 lb/cu ft |
| Critical Temperature |
-232.87°F (-147.15°C) |
| Critical Pressure |
492.45-psia (33.5-atm) |
| Specific Volume @ 70°F, 1-atm |
13.8 cu ft/lb
or 31,000 cu in/lb |