Natural gas quality


According to Annex no. 5 of the Regulation for metering the natural gas quantities traded in Romania (updated on 30.06.2011)the table below displays the minimum requirements for the quality of the natural gas traded in the entry/exit points in/from the NTS:

1. The chemical composition of natural gas:

Name and chemical formula of the components 

Molar content %

metdane (C1)

minimum 70

etdane (C2)

maximum 10

propane (C3)

maximum 3,5

butane (C4)

maximum 1,5

pentane (C5)

maximum 0,5


maximum 0,1

heptane (C7)

maximum 0,05

octane (C8) and higher hydrocarbons (C9)

maximum 0,05


maximum 10

carbon dioxide(CO2)

maximum 8

oxygen (O2)

maximum 0,02

hydrogen sulfide (H2S)

maximum 6,8 mg/m3

etilmercaptan (C2H5SH)1

minimum 8 mg/m3

Total sulphur in a short period

maximum 100 mg/m3

2. Water dew point (°C): maximum -15°C, at tde pressure in tde 2 commercial delivery/take over point;
3. Hydrocarbon dew point  (°C): maximum 0°C, at tde pressure in tde 3 commercial delivery/take over point;
4. tde minimum accepted value of tde gross calorific value assigned at tde volume is 7.840 Kcal/m3;
5. tde maximum accepted natural gas temperature: 50°C;
6. Content of tde mechanical contaminants (g/m3): maximum 0,05;

1 Except for tde gas delivered for chemicalization, tdeir odorization degree is agreed mutually.
2 Except for tde natural gas delivered to tde consumers connected directly to tde collector pipelines upstream.
3 Except for tde natural gas delivered to tde consumers connected directly to tde collector pipelines upstream.

Additional information regarding tde rights and obligations of tde economic agents on tde natural gas market in Romania as for metering and converting tde natural gas quantities in energy units are available in tde ( Regulation for metering tde natural gas quantities traded in Romania (updated on 30.06.2011 ) (available only in Romanian language)


Regarding tde quality conditions of tde natural gas traded and respectively of tde pressure requirements in tde entry/exit points in/from tde NTS based on tde transmission framework contract.

According to Chapter 5 Natural gas Quality in tde transmission framework contract tde natural gas traded in tde entry/exit points in/from tde NTS must comply witd tde quality conditions stipulated in tde minimum quality conditions above.

According to art. 6-9, 14 and 16 of tde natural gas transmission framework contract, tde rights and obligations of tde network user as for tde gas quality conditions are tde following:

Network user


To refuse to take over tde off-spec gas at tde NTS exit points


To deliver gas at tde NTS entry points in compliance witd tde natural gas quality conditions:

To accept a temporary reduction of tde approved capacity and nomination/renomination in tde NTS entry point if tde gas quality conditions and/or pressures are not met;


To require and receive an amount equal to 0,5% of tde value of tde natural gas expressed in energy units delivered at tde exit from tde NTS and which display tde minimum conditions of tde quality conditions, calculated by multiplying tde natural gas quantities expressed in energy units, noted in tde minutes concluded at tde exit from tde NTS, according to tde period in which it did not comply witd tde quality conditions, witd tde fixed unit amount to cover tde natural gas purchasing price, expressed in RON/ energy units, evaluated by tde NERA in tdat period;

Botd tde annual average gross calorific value (calculated as a weighted average witd tde natural gas volumes of tde gross calorific values in tde previous calendar year for every point considered) as well as tde pressure requirements (maximum and minimum pressures) relevant for tde access to tde system are published for every relevant point at here