The radio rang when a fire broke out in a nearby hotel on the fifth floor. A few minutes later, you are using your riser bag to make connections—that is, “dress the pipes”—on the landing on the fourth floor, and on the upper floor above you, it seems that a sprinkler system is faulty. Hotel. This is most likely a stressful situation that you may or have never experienced before; doing the small things right will help overcome the stress, and small successes will turn into big successes. Some people may think that one of the rather small things is the prompt, “Don’t forget to rinse!”
Flushing the riser before it is used by the fire department is not a small task, but it is a critical step that can be used for multiple purposes and significantly affect the results of firefighting operations. Flushing confirms the integrity of the riser, its water supply and valve operation; flushes debris in the pipeline; and gives you time to solve problems in advance.
The water flowing from the riser confirms that the pipe has a source of water. There are multiple water supply possibilities for riser systems; we must know some general options. The pipes can be supplied by pressurized fire pumps, municipal water sources with or without sufficient pressure, or Fire Department Connection (FDC) only. Hope you have planned this building in advance and understand the system you want to use. In many pressurized fire pump systems, when you open the valve for flushing, the system pressure will drop, and the fire pump will sense the pressure drop, then start and provide pressurized water to the system. This is ultimately what you want to happen to the system provided by the building fire pump.
Similarly, when the FDC and the engine are connected and fully pumped, water will flow out when the valve is flushed, and everything is fine. However, if you open the valve and no water flows out, it may mean that the valve at the bottom of the pump room or stair riser is not opened, the engine is connected to the wrong connection, or any other reason. Maybe the fire pump is disabled or the riser itself is damaged, However, no water flowing out of the pipe may be a completely normal result for manual dry risers or manual wet systems that rely on FDC for water supply and are not connected.
The riser valve may have not been used in the building for many years, or it may have been damaged due to criminal intent or damage by curious building occupants in the past few days. From the first installation or last use to the day you need it to work, many things can happen. To ensure success, remove the cover and install the fire department gate valve (photo 1) before opening the building valve. You carry this valve with you, you know it can work, and you have received its training before that day.
After installing the fire department valve, open the building valve once to flush the system, and then keep it open. Opening a building valve may require work; it is expected to be difficult to open. Do whatever you have to do to open it-hit it, pry it, or use a pipe wrench. Once it is open and you have flushed the system, keep the building valve open and use the fire department gate valve to shut off the water flow. The operator can continue to trim the pipe and add elbows, embedded meters, hoses, etc., so that the pipe is ready for use (photo 2-3). The gate valve of the fire department will allow the stairwell riser firefighters to set the correct pressure when the pipeline is flowing through the stairwell before firefighting; in unknown circumstances, using a gate valve to close the water flow is usually much easier than using a building valve. Once the fire is extinguished and the operation is over, the staff can deal with closing the building valves to restore their equipment services.
The necessity of flushing debris from the riser system is easy to understand. Hard water deposits, scale, toys, garbage, and any number of things can enter the standpipe system. Flow enough water to flush these items out of the system and onto the platform. It is easier to flush foreign objects through the 2½-inch valve than through the 11⁄8-inch nozzle tip. Flushing and drying the system will not only flush away the debris, but also flush out the air accumulated in the system to prepare the system for fire fighting. Taking a little time now to flush out objects that might clog the nozzles can be rewarded in countless ways in fire fighting operations.
In the end, the staff did not want to forget to rinse, because it gave them time to overcome the problem. Firefighters in the stairwell should drain a large amount of water from the riser as soon as possible, while other workers are lengthening the pipeline and preparing for firefighting operations.
For example, if the building has a manual dry valve and the engine staff outside report that they are connected to the building and supply water, but the riser firefighter opens the stairwell valve but nothing comes out. What is the problem? Is the system damaged, is the pump chamber valve closed, or is the engine connected to the wrong riser connection? The faster the incident commander learns of the problem, the easier it is to fix it without significantly increasing the response time (the time from dispatch to fire suppression). Photos 4 and 5 show riser firefighters found in an inhabited building in Oklahoma City, Oklahoma. The area was pre-planned and the riser connection was discussed with new members.
Another example of stopping firefighters is the manual wet system connected to the lower floors, with many floors above the fire scene. The wet system is filled with water but is not connected to a pressurized water supply system. At the junction of the fifth floor of the 10- to 15-story building, there is a 120 to 150-foot-long water-filled riser system above the junction. This will create a head pressure of 60 to 70 pounds per square inch (psi) from the water above the valve in the pipeline. Remember that every foot of rise in the riser will apply 0.434 psi of pressure.
In the example above, 120 feet × 0.434 = 52 psi, and 150 feet × 0.434 = 65 psi. If you only let the valve flow for one second, the system seems to have enough pressure and water volume. However, in reality, the pipe only drains water from the pipe above it, because the standpipe is designed to enable the fire department to provide water for actual fire fighting. This is why it is important to flush enough water to determine whether the pipe is simply drained or supplied from a water source.
A similar situation in this type of system is that sometimes a small controlled pump supplies water in the system. When you open the valve and only a small amount of water comes out, the booster pump will start and slowly try to fill the system. If the crew does not have enough flow, the operator will mistakenly think that there is a water source. The faster staff learn about the answers to these questions, the faster they can deal with and overcome them.
If you take the time to prepare, the riser operation can be systematic and stress-free. Practice these little things, mix training randomly, and try to solve possible standpipe complications. Remember, when we do the small things right, they add up to a great success, which can make the riser firefighting work go smoothly.
JOSH PEARCY started his firefighting career in 2001 as a lieutenant in the Oklahoma City (OK) Fire Department and was assigned to a special rescue station. He is a national registered paramedic and firefighting, EMS, diving and technical rescue instructor. He is a lecturer of FDIC International and a search and rescue team manager/helicopter rescue expert for the OK-TF1 urban search and rescue team.
Post time: Jul-05-2021
