Oil and gas companies use pressurized natural gas (i.e. instrument gas) to operate pneumatic actuators and controllers. These controllers are essential for managing process flows at wellheads, compressor stations, and processing plants. Pneumatic actuators controllers direct the opening and closing of valves, the level of fluids in tanks and separators, and the temperature, pressures, and flow rates of oil and gas.
In most industry pneumatic devices are generally controller with clean and dry compressed air, which is called instrument air. Instrument air is generated with an electrically driven air compressor and drying equipment. At many oil and natural gas production and processing sites, however, there’s insufficient electrical power to drive an air compressor. Pressurized instrument gas, however, is readily available and can be used in lieu of compressed air.
Operators face certain challenges when using instrument gas. The gas is normally contaminated with liquid water, water vapor, and liquid hydrocarbons. These contaminants easily fowl actuators and pneumatic controllers. Freezing is the most common problem that users of instrument gas experience. Instrument gas lines are usually small diameter pipes or even ¼” tubing. The flow rates of gas are very small, usually 1 SCFM or less. This means that instrument gas, even after being drawn from a warm source, chills to the ambient temperature before reaching the pneumatic device. In operating area that experience even intermittent spells of low ambient temperatures, instrument gas lines are prone to freeze-ups. A single frozen instrument gas line has the potential to shut down an entire production site.
Van Air Systems offers several simple, effective, and affordable solutions for instrument gas drying and filters. ID Series dryer combined with an appropriately sized F200 filter lower the dew point of instrument gas to -40⁰F/C and remove virtually all mists and solid particulates.