ANCHOR AND BRACE PROPANE TANKS AND GAS CYLINDERS Protecting Your Property from Earthquakes FEMA April 2008 During earthquakes, propane tanks can break free of their supporting legs. When a tank falls, there is always a danger of a fire or an explosion. Even when a tank remains on its legs, its supply line can be ruptured. Escaping gas can then cause a fire. Similar problems can occur with smaller, compressed gas cylinders, which are often stored inside a house or garage. One way to prevent damage to propane tanks and compressed gas cylinders is to anchor and brace them securely. The figure shows how the legs of a propane tank can be braced and anchored. Using a flexible connection on the supply line will help reduce the likelihood of a leak. Compressed gas cylinders cannot be permanently anchored because they have to be periodically replaced. But you can use chains to attach them to a wall so that they will remain upright. [Begin illustrations] The first illustration shows a propane tank. You should bolt the legs to a concrete pad, weld bracing to legs, and have a flexible connection. The second illustration is an upright gas cylinder. It should have a chain restraint, 3/16” min. welded closed-link steel chain (safe working load 500 lb); a ¼” diameter screw eye (or expansion anchor to concrete), a 1/4” min. threaded connector (safe working load 500 lb). Stronger hardware and wall support is required for multiple cylinders. Engineering recommended. [End illustrations] BENEFITS OF UTILIZING THIS MITIGATION STRATEGY * Helps to prevent the tanks from breaking free from their support legs, which could cause fires or explosions TIPS Keep these points in mind when you anchor and brace propane tanks or compressed gas cylinders: * Before you alter your propane tank in any way, make sure that the tank is your property and not rented from the propane supplier. Before welding new bracing to the tank legs, you must remove the gas from the tank. You should also check with your propane supplier to find out whether additional precautions are necessary. * Clear the area around the propane tank to ensure that there are no tall or heavy objects that could fall on the tank or rupture the supply line. * Keep a wrench near the shutoff valve and make sure the members of your family know how to turn off the supply line if they smell a gas leak. On larger tanks, such as farm tanks, consider installing a seismic shutoff valve that will automatically turn off the gas during an earthquake. * Provide a flexible connection between the propane tank and the supply line and where the supply line enters the property. But keep in mind that adding a flexible connection to a propane tank line should be done by a licensed contractor, who will ensure that the work is done correctly and according to all applicable codes. This is important for your safety. * To attach a compressed gas cylinder to a wall, use two lengths of chain around the cylinder – one just below the top of the cylinder and one just above the bottom. The chains should be attached to eye hooks that are screwed into the wall. In wood-frame walls, the eye hooks must be long enough to penetrate not just the wall but the studs behind it as well. In concrete or masonry block walls, the eye hooks should be installed with expansion anchors or molly bolts. ESTIMATED COST Bracing and anchoring a propane tank will cost about $250. Having flexible connections installed on the tank and at the property will cost about $75 for the chain restraint. Attaching one gas cylinder to the wall will cost about $30 per linear foot and $50 for single units. OTHER SOURCES OF INFORMATION FEMA 74, Reducing the Risks of Nonstructural Earthquake Damage: A Practical Guide, Third Edition, September 1994, http://www.fema.gov/library/viewRecord.do?id=1574. FEMA 232, Homebuilders’ Guide to Earthquake-Resistant Design and Construction, June 2006, http://www.fema.gov/library/viewRecord.do?id=2103. To obtain copies of FEMA documents, call the FEMA Publications Warehouse at 1-800-480-2520 or visit FEMA’s Library online at http://www.fema.gov/library.