How to Update Propane Lines in a Camperby John Cagney Nash
Propane, which used to be called liquefied petroleum gas (LPG), is a colorless, nontoxic and almost odorless hydrocarbon. Ethyl mercaptan is added to produce an identifying odor similar to rotten eggs. Propane is used in a camper to power water and space heaters, and for convection ovens and stove-top burners. Some recreational vehicles (RVs) are also equipped with a propane-powered electrical generator. The main gas supply line under a camper is vulnerable to compression damage from road contact or to crimping from inadvertent jacking, and internal spurs can become worn or fragile. In these situations, an update of the propane lines is advisable.
Build the main under-vehicle delivery line, between the regulator and the appliance spurs, from black iron pipe. Black iron pipe is rigid and so lends itself to spanning long runs between the ribs under a camper, so long as sufficient support hangers are used. Specialist tools will be required to cut and thread the pipe. When installing fittings, use thread sealer compound rated for gas. Normally a 5/8-inch bore is sufficient for the black iron pipe main delivery line.
Fabricate the spurs from the black iron pipe main delivery line to each appliance from propane-rated soft copper tubing. Soft copper tubing is extremely flexible and easy to work with, lending itself to being snaked through tight spaces inside cabinets and under appliances. Use a wheel cutter to cut the tube, and a kit of flaring tools to make joins. Usually a 3/8-inch bore is sufficient for the copper tube spurs, and most camper appliances will have 3/8-inch fittings.
Fit a spur to the exterior of the camper and install a quick-disconnect fitting if you intend to operate a propane grill or camp stove from the camper’s tank. These fittings may be bought at stores specializing in cooking equipment.
Install an inline shut-off valve rated for propane after every junction between the iron pipe and copper tube, three inches up the copper tube. Locate the valves where they are away from appliances but easy to access, usually beneath the camper and close to an outside edge.
Clean the exposed black iron pipe with mineral spirits on a rag. Prime with a metal primer, and then topcoat with an oil-based exterior paint.
Insulate both the iron pipe and the copper tubing to protect it from chaffing and rattling when the vehicle is under way. Use rubber grommets everywhere it passes through a hole or a support bracket.
Turn off all inline shut-off valves. Install an inlet adapter fitting at the end of the black iron pipe left open for the regulator, and use a bicycle pump to pressurize the system to ten pounds. Test every join using proprietary liquid joint testing fluid.
Fit a two-stage regulator, which first reduces container pressure down to 10 pounds per square inch (PSI), and then down to 10 or 11 water column inches, the optimum pressure for propane-fueled appliance operation. Regulators use a vent which allows the diaphragm to breathe, and that vent must be angled to within 45-degrees of pointing straight down. Recreational Vehicle Industry Association (RVIA) code mandates that the regulator should be covered or located in an enclosed compartment.
Install a propane detector inside the camper. Some propane detectors make a piercing noise when activated, whilst others also actuate a solenoid valve that automatically shuts off the supply of propane.
Check that all appliances are switched off. Have your licensed propane supplier inspect the updated propane system before he first gasses it up. Charge the system with propane, and test every appliance at the fitting to the new copper spur using proprietary liquid joint testing fluid.
Items you will need
- Black iron pipe cutting tools
- Black iron pipe threading tools
- Copper cutting wheel
- Copper flaring tool kit
- Set of wrenches
- 5/8-inch black iron pipe and fittings
- Propane-rated thread sealing compound
- Support hangars
- 3/8” propane-rated soft copper tubing
- Flared copper tube fittings
- Quick-disconnect fitting
- Inline shut-off valves
- Metal primer
- Oil-based exterior paint
- Rubber grommets
- Inlet adaptor fitting
- Bicycle pump
- Proprietary liquid joint testing fluid
- Two stage regulator
- Propane detector
- Gasflamme 2 image by Stefan Balk from Fotolia.com