Method for separating air by cryogenic distillation in an installation comprising a column system (31, 33), of which one column operating the highest pressure called the average pressure, wherein: - all the air is brought to a high pressure, higher than at least 3 bars to the average pressure, purified at this pressure in a purification unit - all the air is sent at the release temperature from the purification unit to an exchange line; - all the air is cooled in the exchange line and a part of the purified air is compressed by means of at least one first compressor at one single stage and sucking at a first intermediate temperature from the exchange line; - at least one part of the compressed air in the first compressor is compressed by means of at least one second compressor at one single stage and sucking at a second intermediate temperature from the exchange line and is sent into the exchange line where it is cooled, then liquified, possibly at the cold end of the exchange line and is sent into the column system after release; - another part of the purified air under high pressure is cooled in the exchange line then at least in the released part in at least two turbines (17, 27) having one or several start temperatures which is an intermediate temperature or which are intermediate temperatures of the exchange line then sent to the column system to be separated; - the work released by the release of air is used at least partially for the cryogenic compression carried out by the first and the second compressor, by coupling the first compressor to one of the two turbines and the second compressor to the other of the two turbines; - the liquid oxygen is pressurised at a pressure less than or equal to 16 bars, preferably between 10 and 16 bars, and is vaporised in the exchange line, characterised in that the part of air compressed in the first compressor constitutes between 10% and 35% of the purified air and the part of released air in at least two turbines constitutes between 65% and 90% of the purified air, the part of air compressed in the first compressor is cooled in the exchange line above the second compressor, an energy dissipation device (22, 24) is coupled with at least one of the compressors, the first intermediate temperature differs from the second intermediaite temperature by at most 10°C, and the first and second temperatures are between -145°C and -165°C, and the release temperatures of the first and second compressor (15, 25) are between -110°C and -150°C. - all the air is brought to a high pressure, higher than at least 3 bars to the average pressure, purified at this pressure in a purification unit - all the air is sent at the release temperature from the purification unit to an exchange line; - all the air is cooled in the exchange line and a part of the purified air is compressed by means of at least one first compressor at one single stage and sucking at a first intermediate temperature from the exchange line; - at least one part of the compressed air in the first compressor is compressed by means of at least one second compressor at one single stage and sucking at a second intermediate temperature from the exchange line and is sent into the exchange line where it is cooled, then liquified, possibly at the cold end of the exchange line and is sent into the column system after release; - another part of the purified air under high pressure is cooled in the exchange line then at least in the released part in at least two turbines (17, 27) having one or several start temperatures which is an intermediate temperature or which are intermediate temperatures of the exchange line then sent to the column system to be separated; - the work released by the release of air is used at least partially for the cryogenic compression carried out by the first and the second compressor, by coupling the first compressor to one of the two turbines and the second compressor to the other of the two turbines; - the liquid oxygen is pressurised at a pressure less than or equal to 16 bars, preferably between 10 and 16 bars, and is vaporised in the exchange line, characterised in that the part of air compressed in the first compressor constitutes between 10% and 35% of the purified air and the part of released air in at least two turbines constitutes between 65% and 90% of the purified air, the part of air compressed in the first compressor is cooled in the exchange line above the second compressor, an energy dissipation device (22, 24) is coupled with at least one of the compressors, the first intermediate temperature differs from the second intermediaite temperature by at most 10°C, and the first and second temperatures are between -145°C and -165°C, and the release temperatures of the first and second compressor (15, 25) are between -110°C and -150°C.