Natural Gas Preheaters

Preheaters of Natural Gas

Natural gas is one of the most commonly used fossil fuels. It supplies energy for industrial as well as residential purposes. It is eco-friendly in nature, and is a very popular energy source. However, natural gas cannot be used unless it is processed. Transporting natural gas from its origin to processing facilities is also a very difficult task. The transportation of natural gas through pipelines requires high pressure with the pressure levels of 200 to 1,500 pounds per square inch (psi).There are two primary reasons to compress natural gas in such high pressure level. The volume of natural gas can be reduced as much as 600 times under high pressure. Besides, it helps greatly to drive forward the gas through the pipelines under high pressure. Conversely, it is not possible to use high pressured natural gas locally unless it is brought down to 3 psi or so. It can be regulated at the distribution network to control the pressure of gas ensuring an optimal flow. The catch is that the temperature of gas will tremendously drop along the way when the pressure drops.


When the pressure of natural gas decreases by 88%, the temperature also decreases by about 65%. The drop in temperature, known as Joule Thompson effect in physics, can cause an operational and quality problems. WATTCO™ addresses the issue of temperature decrease by designing preheaters that are particularly suitable for the highly flammable environment. The best electric heater that is suitable for preheating natural gas is the circulation heater with stainless steel flanges with NEMA 7 control panels.The benefits of having WATTCO™ gas preheaters are that they are digitally controlled for precise controls in dangerous environments. Having NEMA 7 explosion proof enclosure is a very adequate safety measures taken in the given gas preheating application purpose. The natural gas preheaters are generally designed to prevent the Joule Thompson effect using Electrical Block Type Process Heaters. It is an indirect heater with aluminum encased block protected by stainless steel or carbon shell. It is called heat exchangers and is one of the best methods to heat up the natural gas before transmission. The thermal carrier fluid used for heat exchangers are either hot water or steam. The design allows the thermal carrier to enter form the top of the heat exchanger through the tubes and leave at the bottom. The natural gas is exposed to the thermal carrier for the maximum duration to achieve the optimal results for heat exchanging.

Safety Measures

Preheaters for natural gas perhaps requires one of the stingiest precaution for safe operation and maintenance. The gas preheaters designed by WATTCO™ incorporates several safety measures necessary to ensure the safe control of the heaters. Thermocouples are used at each inlet and outlet of preheaters to monitor the temperature increase. Instead of contactors, silicon-controlled rectifiers (SCR) were used to reduce the chance of control failure. Of course, the NEMA 7 terminal enclosure is an excellent way of protecting the control panel in the hazardous environment such as natural gas processing facility. All these combined makes WATTCO™ preheaters one of the safest preheater of the industry.