Cummins/Onan — Propane (LPG) Fuel System Installation
Installation
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Before you start
- Liquid LPG fuel presents hazard of explosion or fire.
Procedure
- Use clean, fresh commercial propane or HD-5 grade liquid propane gas in a mixture of at least 90 percent propane.
- Install all propane fuel lines so they are accessible yet protected from damage.
- Use metal straps without sharp edges to secure fuel lines.
- Keep fuel lines away from hot engine or exhaust areas.
- Do not run fuel lines in conjunction with electrical wiring.
- Vehicle propane fuel supply tank must have a dip tube to ensure liquid withdrawal.
- Mount an excess flow valve internal to the propane fuel supply tank per NFPA 501C Paragraph 3-4.4.
- A valve rated at 2.6 gallons per hour (9.9 l/hr) flow rate and 6.5 psi (45 kPa) differential pressure is recommended.
- Mount a manual shut-off valve on the propane fuel supply tank; keep fully open when operating generator set.
- Install a hydrostatic pressure relief valve between the manual shut-off valve and the propane fuel solenoid valve and filter assembly.
- Install an approved flexible non-metallic non-conductive and non-organic fuel line between vehicle fuel system and generator set.
- Onan recommends seamless steel tubing and flared connections for long runs.
Specs & values
- 2.6 gallons per hour (9.9 l/hr) flow rate
- 6.5 psi (45 kPa) differential pressure
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.