REALISTIC TRAINING FOR LPG EMERGENCIES
Built in the summer of 1991, the Meadowood County Area Fire Department’s liquefied petroleum gas (LPG) training facility, part of the Meadowood County Area (Fitzwilliam, New Hampshire) Fire Department and Training Center, features seven stations, each teaching a different LPG firefighting evolution.
Meadowood’s principal LPG instructor, Ed Anderson, a Meadowood firefighter and certified fire instructor with 20 years of experience in the LPG industry, had been teaching Meadowood’s LPG classes using a very simple installation. His and the fire school management’s concerns about safety and providing students with the most realistic training possible led to researching and planning a new, more comprehensive facility. Several years of planning culminated in 1991 in a seven-station design in which each station provides trainees with a different LPG firefighting evolution. The training includes an eight-foot by eight-foot concrete pad, a manhole, city gas meters, twin 100pound cylinders, a 125-gallon tank, a 500-gallon tank, and a gas delivery truck (bobtail). These props are arranged in a straight line so that everything is easily visible from the safety officer’s elevated control station.
Station I. The first station consists of the eight-foot by eight-foot concrete pad, which provides a place to work with “tip-overs” of 100-pound cylinders. Meadowood now can safely train students for situations involving cylinders leaking vapor or liquid.
Station 2. The prop at the second station is a manhole about six feet in diameter, similar to a street storm drain with a grate on top. It is approximately three feet deep and has a runoff drain at the bottom. A vapor gas line is piped into this prop, and a street valve shutoff is a couple of feet in front of it. The end of the gas line has a cap in which small holes have been drilled so that it makes a nozzle. This station trains students in two evolutions: the use of combustible gas indicators for evaluating situations involving leaks or complaints of “a smell of gas” and a vapor fire dealing with an underground (below-grade) incident, created by lighting in the manhole.
Stations 3 and 4 Hie third and fourth stations are side by side on a five-foot-high concrete block wall. The first prop consists of LPG vapor piped into a pair of gas meters such as those found in city gas installations. The meters are drilled out so the gas passes through the meter case. When used, fire involves the entire meter and banks off the wall behind it.
While the manhole has a gas service street valve shutoff on the line coming into it, this third prop, along with all of the others, has a 90-degree ballvalve shutoff in front of it. The students must operate this shutoff to close down the gas flow and thereby control the emergency. All stations have additional safety shutdown features, which are described below.
(Photos by author.)
Next to the city gas meter prop is a twin 100-pound cylinder installation, the kind used in rural areas with “bottled gas.” Like the meters, this prop is plumbed with a vapor line so that, when in use, all the area around the top of the tanks, the valves, and controls on the wall are involved in fire; fire also banks off the wall behind the tanks. T he students again must control the situation with the ballvalve in front of the prop.
Station 5. The prop here is a 125gallon cutaway gas tank with vapor and liquid gas lines piped into it. Each of the two lines has safety shutdowns and ball-valve controls. They then are piped together so that only one linepasses through the tank. The piping ends with a nozzle at the top of the tank. Vapor or liquid fires can be set at the top of the tank, simulating problems with a damaged or broken valve.
Station 6. A 500-gallon cutaway tank with separate vapor and liquid lines piped to it is the prop at this station. The liquid line goes through the tank to a nozzle at the top, as in the case of the 125-gallon prop. The vapor fine is piped into a burner below the tank. This prop is used for evolutions of fire impinging on a tank and the resulting activation of the tank’s relief valve.
Station 7. Still waiting to be installed, the gas delivery truck (bobtail) at this station was donated by the Keene Gas Corporation. All of the flammable material will be removed from the unit, and it will be plumbed with vapor and liquid lines, for engine compartment and interior cab fires. In addition, fires and leaks around the tank and the pump and product offloading areas at the rear of the unit will be simulated.
DESIGN AND SAFETY FEATURES
Two 1,000-gallon supply tanks piped for liquid and vapor operations supply the propane for the installation. The gas flow is controlled from the safety/control tower and by the emergency shutdown controls. All of the below-ground piping is schedule 80 gas pipe, coated and wrapped to National Fire Protection Association and American Gas Association standards. Schedule 40 steel pipe is used aboveground where gas is not contained between valves.
The unique feature of this installation is that the emergency shutoff valves located at each prop are operated by electric solenoids. These valves are underground. They are placed in the lines just before the controls the students operate during the various evolutions. The normal position of these valves is closed, or “off.” When activated with a 24-volt current, they open. Should an emergency arise, they can be closed instantly by the operator at the control tower by shutting off the gas supply. When closed, the valves leave only the product in the last two to three feet of the line to burn off.
These valves and the gas controls are operated by an operator/safety person from a raised control station, described below.
At the new installation, the area around, behind, and in front of the site is graded with 1’/2-inch stone; underground drainage is along the front edge. This arrangement ensures that the students will work in a safe and relatively dry area with secure footing. One of the major problems with the old site was excess standing water.
The control station is a six-foot square platform raised four feet above grade. It is situated so that the safety officer/operator has a clear view of the props, students, and instructors. This position is crucial to providing safe operations. The operator also has the authority to stop any evolution that appears to be unsafe or presenting problems.
Control station. An electric control/selection panel at the station determines which of the seven stations will operate. Control valves for the gas lines are also at this station. To flow propane to any given prop, the gas valve for that line must be open, the main power switch on the electric control panel must be on, the selector switch on the control panel must be turned to that prop, and the operator continuously must push down an electric “dead-man” switch to open the desired solenoid shutoff valve in the gas line feeding the prop. When the dead-man switch is held down, the solenoid valve opens and product flows. When it is released, the solenoid closes and the gas flow stops immediately.
Two sets of gas control valves are at the control station. One set controls the vapor lines and the other controls the liquid. A total of nine separate gas lines feed the props; each line has a solenoid shutoff valve. Three of them are liquid lines and six are vapor lines. The operator selects the feed from the supply tanks and then the line for tiltprop in use with 90-degree hall-valve shutoffs. This way, the only line open for gas How is the one to the prop in use. The amount of gas flowing—and thereby the size of the fire —is determined, of course, by how much the operator opens the valves. In this way, students can experience a fire building in intensity or, depending on the action taken by the students, the operator can cause the fire to flare up or rekindle.
Since gas lines not in use become pressurized vessels while they have product in them, each line has a pressure-relief valve. When the site is not in use, all of the lines are drained and the supply tanks are shut off and secured behind a locked fence. The electric controls are removed from the site so vandals cannot get gas to flow through the props.
At present, a fire starter with a flare on a pole is used to light the fires. However, we are exploring ways to have the control station operator ignite the fire by remote control.
The water supply presently is provided by two four-inch hoselines from the 1,000-gpm pumps supplying the entire drillground. There are two separate sources so that a backup source will be available if one source fails. The two lines Siamese into a four-way distributor valve, and two two-inch handlines with fog nozzles are used for the evolutions, with another twoinch line as a backup for the students’ protection. One of Meadowood’s goals for the coming year is to extend the underground hydrant system from the pumphouse to the LPG site.
The Meadow’ood membership voted to spend up to S5,500 to construct this installation, and the board of directors provided another S 1,000 from its funds. The total cash outlay was about S 5,700. In addition to the cash costs, Meadowood had secured the donated services of three professional gas installers for three weekends, the donated services and equipment of one of our members for the site work, and the donation of the time and expertise of many of our members, who did the work. Furthermore, we already owned the tanks used for the props. Keene Gas Corporation placed the supply tanks at the training site with full knowledge that other suppliers also would be filling them with LPG.
It is possible that a state-of-the-art installation like this one could be built anywhere in the country for less than S 10,000 by involving the local gas services and other community resources.
The facility has enabled Meadowood to provide safe, effective training in LPG fire suppression for the fire service and the gas industry.
