Fuel System Safety Precautions: Notes
CAUTION:
Natural gas in fuel system is at high pressure at all times. To avoid injury or fire, release fuel pressure from fuel system before disassembling any fuel system component. To release fuel system pressure, follow pressure relief procedure. See FUEL SYSTEM PRESSURE RELEASE
under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - F150 PICKUP - BI-FUEL - GASOLINE/CNG article. After performing fuel system pressure relief procedure, a small amount of pressure 3 psi (21 kPa) will remain in fuel rail, and high pressure still exists in fuel tanks. Prevent combustion from escaping fuel; no smoking, open flames or any kind of arcing.