The flametube-type heaters produced by GASCAT are designed to heat gaseous fluids with maximum efficiency and to operate safely in hazardous areas. Their main purpose is to preheat Natural Gas before it enters the pressure reducing station, where a simultaneous drop in temperature occurs due to the Joule-Thompson effect. The instrumentation of these heaters includes an interlocking system that controls the operation of instruments such as flow control valves, pressure valves, and temperature valves.