Fire Fighters Learn to Handle Gas Line Incidents in Philadelphia
Robert T. Burns photos
In a cooperative training program, Philadelphia fire fighters are attending a two-hour training course conducted by the Philadelphia Gas Works (PGW) to learn how to handle incidents involving the gas distribution system.
At 9 a.m. Tuesday, Wednesday and Thursday each week, one ladder and two engine companies report to the PGW Safety Training School for a program that was developed by the fire department and PGW officials. The school site was completed last year at Tioga Street and the Delaware River in the northeastern section of the city.
After development of the program, Fire Commissioner Joseph R. Rizzo decided that all members of the fire department, including chief officers and fire marshals would have to attend the safety course.
Each class starts with a lecture by a Philadelphia Gas Works instructor. This is followed by a slide program describing the gas system that serves 670,000 customers in the city. Included are explanations of PGW overpressure protection methods, inspection of regulating and control devices, inspection of construction, underground street troubles and the utility’s continuing leak survey.
The fire fighters learn how PGW distributes gas from two plants and how in most areas regulator stations reduce gas pressure to 1/4 psi. Less than 10 percent of the system has higher pressure.
Since fire fighters arrive at a fire before gas company personnel, it is important that they know how to eliminate or control hazards.
At the training field, fire fighters see gas piping, meters, regulator installations, etc., that have been built throughout the 2-acre facility.
Most familiar to the fire fighters is a basic device found in every gas installation, the meter, and they learn how to turn it off. Basic? Perhaps, but it is stressed to the fire fighters that if they reach out with their left hand while facing a meter, they will find the shutoff valve. If it is in line with the pipe, it is turned on. If it is across the pipe, it is shut off.
A meter is then set on fire and allowed to burn until the lead-sealed faceplate drops off. After the gas is shut off, the meter continues to burn, emitting a black smoke. The instructor explains that combustibles within the meter are burning and will create no hazard. At this stage, the fire can safely be extinguished with no danger of explosion.
Once a meter is shut off by fire department. personnel, the instructor warns, it should never be turned back on by anyone except gas works employees.
The course stresses that the fire department should turn off the gas supply in a burning building, even though the fire may be in a part of the building far from the meter.
All Philadelphia ladder companies carry a gas key to close curb valves. The use of this key on a curb box is demonstrated and the men are told where they can expect to find curb boxes.
A display board, next on the demonstration list, shows all types of meters, including the parallel installation of meters. In this type of installation, the instructor warns, never close both inlet and outlet valves because this will trap gas inside a meter and under fire conditions, this gas could expand and rupture the meter.
The instructor emphasizes, “Shut off only one valve—the inlet valve. That is safe.”
In sections of the city fed by a medium pressure system of 3 to 5 psi, fire fighters must be able to identify three things in a building: the meter, regulator valve and shutoff valve.
On industrial meters, the large valves indicate whether they are on or off. On this type installation, there is usually a bypass valve. This valve always has a padlock on it and is in the off position. Fire fighters are cautioned never to touch it.
In the outdoor demonstration, gas is released in high pressure piping, 15 psi, and set on fire at a flange and at a split weld in an elevated pipe to familiarize fire fighters with the sight and sound.
Should fire or trouble arise in a district regulator station, which is below ground, the advice is, “Keep people away, and keep fire department personnel out, pending arrival of the PGW crew.” This type of installation can be recognized by a green painted post with a 4-inch vent aboveground.
Through this familiarization course about mains, service lines, connections, meters and regulator stations, fire fighters learn what they should do until trained PGW personnel arrive to control the accidental escape of gas.
Overall, this type of cooperative program is designed to give the fire fighters a broader understanding of the PGW operation. Such understanding leads to quicker, more positive action by fire fighters and gas works employees in emergency situations.