Evaluation of the Hazard of Static Electricity in Nonmetallic POL Systems - Static Effects in Handling Jet Fuel in Fiberglass Reinforced Plastic Pipe,

There is increasing interest in fiberglass reinforced plastic FRP pipe for minimizing contamination in ground handling of aviation fuels. This report presents the results of a literature search and experimental study conducted to determine if static electricity hazards would be increased by substituting FRP for metal pipe in such systems. Experiments were conducted in 6 inch diameter, matched volume, carbon steel and Bondstrand 2000 pipes at four fuel conductivities between 0.2 and 5.5 CU and at flow rates between 200 and 1500 GPM at controlled temperatures. Charge generation in the pipes was low. Generation in FRP was generally less than in steel. Relaxation in FRP pipe depended on fuel polarity on the average, relaxation was 8 percent faster, with negatively charged fuel and 30 percent slower with positively charged fuel than in steel. The slower relaxation should not prevent the use of FRP in Air Force hydrant systems handling JP-4 where a minimum of 2 minutes residence time is available downstream of filter-separators.