Fuel for Thought: LP-gas is Quite Safe for Major RV Appliances — When Handled and Maintained Properly

The LP-gas system in your RV provides a high level of convenience, allowing you to run the furnace, water heater, refrigerator and stove/oven.

Although some people get a little nervous about transporting, filling and dispensing LP-gas into the systems, its use is safe with proper maintenance and knowledge.

Trailers, fifth wheels and pickup campers are fitted with one or two LP-gas cylinders and connected to the system through a regulator via a Type 1 hose and Acme fitting. RVs with two cylinders will have a changeover regulator, which allows independent use of the cylinders without an interruption in LP-gas supply; these regulators should be replaced every five years. Once a hose becomes hardened — and possibly brittle — it must be replaced. Screw-on Acme fittings are permanently attached to the hose and also serve as a safety device, interrupting LP-gas flow if they are not seated properly. Fifth wheels with cylinders on opposite sides have a secondary regulator inline, which should also be replaced every five years.

Once the Type 1 Acme pigtail from the LP-gas cylinder to the regulator becomes hard and/or brittle, it’s time to replace it with a high-quality counterpart. The Acme screw-on fitting is also a safety device, which will prevent the flow of propane if it’s not secured properly to the cylinder valve. Note the secondary regulator in the back, which is necessary when the cylinders are placed on opposite sides of the RV.

All RVs should be tested for proper pressure (11 inches water column) every year. This can be accomplished by closing the LP-gas source, connecting a manometer before the secondary regulator (reduces pressure to 10 inches water column) in the stove top and turning the gas back on. For the drop test, connect the manometer tube to the burner valve, open it, and lower pressure using another burner valve to 8 inches water column; there should be no loss of pressure during a three-minute test. Field testing for an LP-gas leak can be performed by coating all connections and fittings, including those on the regulator(s), with a commercial solution that will produce bubbles if there is a leak. Soap will also work, but make sure it is free of chemicals like alcohol; Dawn dish soap is your best bet, if commercial solution is not available.

LP-gas leaks can be volatile when mixed with air, and there are certain simple precautions that should be followed. For one, if you smell propane — it’s laced with mercaptan, which produces a foul odor when leaking — vacate the RV and close the valves on all cylinders (or tank on a motorhome) immediately. LP-gas leak detectors will give you advance warning of a leak, but if they are allowed to time out or become defective, the risk is much higher. Check the expiration date on the back of the device, which will normally allow for five years of service before becoming ineffective. Test the LP-gas detector regularly. Most will have a test button, but exposing the sensor with butane from a lighter will also work: simply blow out the flame while holding the trigger.

Checking for proper system pressure can be performed at the stove top, with the manometer dial gauge hose connected before the secondary regulator after shutting down the LP-gas; after turning on the propane source valve, pressure should be at 11 inches water column. A pressure drop test should be performed annually by attaching the gauge hose to a burner valve, opening the valve and lowering pressure via a second burner to 8 inches water column; if there’s no pressure loss during the 3-minute test, the system is leak-free.

Another key safety element is being aware when refilling the cylinders or tank. Cylinders, of course, are portable, but transporting them safely requires adequate tiedowns and ventilation, and they should be kept in an upright attitude unless they have a horizontal configuration. Cylinder valves must also be capped during transport. All appliances must be turned off when entering a service station for refueling.

One last thought: Make sure the cylinders are secured to the RV properly — and keep them clean and free of rust.

A soapy water solution can be used to field test the LP-gas system for leaks. Simply apply the solution and watch for bubbles, which indicates a leak. It’s best to use a commercial soap solution or Dawn dish soap, which is free of harsh chemicals that can damage the fittings and lines.