The types and classes of F/S identified below are intended for the uses indicated, and for other uses that may be specified, for the removal of undissolved water and solid contaminants from aviation, diesel or motor fuels:

Type I - 15 gpm intended for use in portable refueling systems.

Type II, class A - 50 gpm intended for open field installations.

Type II, class B - 50 gpm intended for use only with the tank and pump units.

Type III. - 100 gpm intended for use in airfield refueling systems, motor fuel servicing equipment, and military pipeline systems.

Type IV - 350 gpm intended for use in air field refueling systems, motor fuel servicing equipment, and the inland petroleum distribution system.

The filter/separators cover by this performance specification are military unique because they must be able to operate satisfactorily at temperatures ranging from minus 25 °F to 140 °F and interface with the military standard filter-coalescer element, which is 3.75 inches in diameter. Commercial filter/separators are not designed to withstand such extreme and sudden operating environmental conditions and their filter-coalescer elements are commonly 6 inches in diameter.