on the other hand any refrigeration capacity not needed in the first heat exchanger is utilized in the second heat exchanger under conditions at which there is insufficient cooling capacity in the residue gas to cool the incoming gas stream to the set point of temperature recorder controller 49 three way valve 48 will be operated to close the entry into line 51 thus sending all of the residue gas stream directly through first heat exchanger 23 bypassing heat exchanger 29 on the other hand at any time that the cooling capacity in the residue gas stream is more than required to bring the incoming stream to the set point of controller 49 a portion of the gas is permitted to pass through pipe 51 and heat exchanger 29 if the temperature of the gas stream as sensed by temperature recorder controller 49 or 49a remains below the set point thereof the entire residue gas stream passes through the second heat exchanger 29 or 29a in the embodiment of fig2 this results in a complete bypassing of heat exchanger 23a in a calculated example according to the invention ten million standard cubic feet per day mmscfd 0 328m 3 s of wet natural gas which is substantially methane but contains minor.