Abstract: The gas conditioner comprises a cooling device including a pulsing tube and switching means for alternatingly connecting said tube to a source of compressed gas and to a consumer. The switching means comprises a double-diaphragm pneumatic relay having a control chamber, an inlet chamber and an outlet chamber. The inlet chamber communicates with the source of compressed gas, and the outlet chamber communicates both with the pulsing tube and alternatingly with the inlet chamber and with the consumer, the outlet chamber communicating with the inlet chamber via a hollow rod overlapped when the pressure in the control chamber approximates that in the inlet chamber. A gate is mounted at the outlet of the outlet chamber, which opens upon the closing of the hollow rod to establish communication between this last-mentioned chamber and a line for supplying cooled gas from the outlet chamber to the consumer.