Issue link: https://onenorgren.uberflip.com/i/565472
Determining filtration requirements Industry standards and manufacturers' recommendations highlight differences in requirements for clean air or gas, depending on the equipment being used. There are some industry standards that provide some guidance for designers and plant operators trying to determine adequate filtration levels. The International Society of Automation's ISA-7.0.01:1996 Quality Standard for Instrument Air sets general standards for moisture content and particulate and oil contamination. This standard sets the maximum allowable oil content at 1 ppm. It requires removal of particles 40 µm or larger, with a caution that some devices require finer filtration. It also states that dew point should be 10°C below ambient temperature. Finally, ISA-7.0.01:1996 states that there should be a sufficient quantity of air for the highest demand situations and that air intake should be free of contaminants. This ISA standard sets a guideline, but it may be too general for certain pieces of equipment commonly used in oil and gas extraction, refining and hydrocarbon and chemical processing. We surveyed literature from multiple oil and gas equipment suppliers to get more detailed information about their clean air/ clean gas requirements. Results of this review are summarised in this table: Clearly, different equipment requires different levels of filtration. The International Organization for Standardization's document ISO 8573-1:2010 specifies classes of compressed air purity for particles, liquid water, moisture vapour and oil vapour. This standard provides a straightforward way to communicate an application's specific requirements and to determine whether a filtration system will meet them A white paper 05 Robust construction High flow Summary of equipment suppliers' clean air/clean gas requirements > Particulates > Water > Oil > Positioners 3-40 µm Dew point 10°C below ambient temperature 1 ppm > Pumps 25 µm Dryer required NA > Transmitters 5-40 µm Dryer required 1ppm > Analysers 1 µm Dew point 10°C below ambient temperature 0.1 ppm > Actuators 25 µm Dew point 10°C below ambient temperature 25 ppm