Abstract: The gate and swing valve has a body which defines at least one valve seat. A closure member inside the valve is pivotably mounted on a support. A cam and cam follower operatively couple the cam to the closure member. A stem has one end coupled to the cam for moving the closure member in a linear motion, in a swinging motion, and then in a linear motion toward the valve seat.

Abstract: The cold decompressed gas flowing into the compression station is preheated by the compressed warmer gas discharged by the station's compressor, thereby raising the temperature of the compressed gas at the discharge outlet of the compressor. The warm compressed gas discharged by the compressor is cooled with ambient air and with the cold decompressed gas stream flowing into the station. If required, to still further reduce its temperature, the cold compressed gas stream is expanded until its temperature approaches the temperature of the gas within the pipeline.The apparatus of the invention includes a gas-to-gas heat exchanger wherein the decompressed cold gas is first preheated by the counterflowing warm compressed gas. The preheated gas is allowed into the inlet of the compressor. The temperature of the warm compressed gas from the discharge outlet of the compressor is first reduced by a gas-to-air heat exchanger.