Home›Repair guides›Cummins/Onan›LPG Fuel System Connection

Cummins/Onan — LPG Fuel System Connection

Installation

From a Cummins/Onan service manual covering: 5.5 HGJAA, 5.5 HGJAB, 6.5 HGJAA, 6.5 HGJAB, 7.0 HGJAA, 7.0 HGJAB. Check it applies to your exact model before use.

Applies to: Cummins/Onan HGJAA, Cummins/Onan HGJAB

Before you start

  • LPG is flammable and explosive and can cause asphyxiation.
  • Testing for gas leaks with a flame can cause a fire or explosion. Use approved methods only.
  • Do not connect the generator set fuel supply line to any appliance fuel supply line.

Procedure

  1. Adjust the gas supply pressure at the gas inlet of the pressure regulator to at least 229 mm (9 in) WC; must not exceed 330 mm (13 in) WC.
  2. Route LPG fuel lines away from electrical wiring and hot engine exhaust components.
  3. Route the LPG vent hose so that it vents to the outside or provide required openings.
  4. For a long fuel line run, use seamless steel tubing with flared ends; use 3/8 inch I.D. up to 0.9 m (3 ft) and 1/2 inch I.D. up to 4.6 m (15 ft).
  5. After installation, fill the LPG tank and test every joint and fitting using an approved method, such as soap bubbles.

Specs & values

  • LPG vapor connection pressure: 3/8-18 NPTF, 228-330 mm (9-13 in) WC
  • LPG fuel line: 3/8 inch I.D. up to 0.9 m (3 ft) or 1/2 inch I.D. up to 4.6 m (15 ft)
  • 6.5 kW LPG systems must have dedicated tank, regulator, and piping/connections

Full service-parts list: Cummins/Onan HGJAA →, Cummins/Onan HGJAB →

Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

More Cummins/Onan repair guides →