SYSTEM, METHOD AND APPARATUS

The present invention relates to an apparatus, system or method for reducing pressure in a gas flow for a gas let-down system. The present invention further relates to an apparatus, system or method for drying gas. A system (10) for reducing pressure in a gas flow for a gas let-down system comprises an expander (102) driven by gas at a first pressure expanding to a second pressure, and a compressor (104) for compressing the gas from the second pressure to a third pressure, whereby the third pressure is lower than the first pressure and the third pressure is higher than the second pressure. By first expanding the gas and then compressing the gas the intermediate temperature of the gas at the second pressure is lower than if the gas is expanded directly to the third pressure. Further, a drying system for drying a gaseous fluid supplying heat to a heat exchanger comprises a liquid separator, a heat exchanger downstream of the liquid separator and a cooler for extracting heat from the gaseous fluid upstream of the liquid separator using the cold gas downstream of the heat exchanger. By extracting heat from the gaseous fluid the temperature of the gaseous fluid at the inlet to the separator can be reduced causing liquid in the gaseous fluid to condense and be separated in the separator.