| Value | Unit | Specification | Notes |
| Wobbe Index | KWh/Nm3 | 13.066-16.328 | |
| Gross Calorific Value (GCV) | KWh/Nm3 | 10.174-13.674 | |
| Relative Density | - | 0.56-0.71 | |
| CH4 | % mole | 75.0 min | |
| CO2 | % mole | 3.0 max | |
| N2 | % mole | 6.0 max | |
| 02 | % mole | 0.2 max | |
| Hydrogen sulfide(H2S) | mg/Nm3 | 5.4 max | In exceptional cases and for a time interval that does not exceed two (2) hours; the content of Natural Gas in Hydrogen sulfide can have a value up to 10.8 mg/Nm3, without however exceeding 6.5 mg/Nm3 as an average Daily value. |
| Total sulphur | mg/Nm3 | 80.0 max | In exceptional cases and for a time period that does not exceed 48 hours it can receive values up to 120 mg/Nm3 without however exceeding 90 Mg/Nm3 as an average Weekly value. |
| Water Dew Point (WDP) | οC | +5 max | Under reference pressure of 80 barg. |
| Hydrocarbons Dew Point | οC | +3 max | Under any pressure from 1 to 80 barg. |
| Dust and Liquids | | | Natural Gas should be practically free from gaseous, solid or liquid substances that could pose blockage or malfunction or erosion risks to standard gas facilities and standardized gas equipment. Exception is made to the cases of liquid formation of minuscule droplets in Natural Gas which are impossible to be removed. |
| Odorizing Substance | | | The Natural Gas is delivered at the Entry Points without odorizing substance. The Odorizing Substance is added at the Exit Points, when necessary as per the ASME Code. |
| Temperature | οC | 0 - 50 | Under special NNGTS operation conditions or due to technical reasons and in any case for periods that do not exceed 4 hours; the temperature may be less than 0°C. In this case, Natural Gas temperature must necessarily be greater than -10°C and at least 5°C higher than the WDP temperature of Natural Gas under operating pressure. |
*Normal Cubic Meter or Nm3 shall mean the quantity of Natural Gas, which at conditions of absolute pressure 1.01325 bar and temperature zero (0) degree Celsius, occupies volume of one (1) cubic meter.
*Gross Calorific Value (GCV): The amount of heat produced by the complete stoichiometric combustion of one (1) normal cubic meter of Natural Gas at a constant absolute pressure of 1,01325 bar when the initial temperature of the fuel mixture and the final temperature of the products of combustion is considered to be twenty-five (25) degrees Celsius and the combustion produced is concentrated in the liquid state. Normal cubic meter means the amount of Natural Gas mass which, under absolute 1.01325 bar conditions and zero (0) degrees Celsius, occupies a volume of one (1) cubic meter.
