Fire Protection Water Supply in the Industrial Environment - Firefighting

2022-12-23 20:36:19 By : Mr. Martin Zhang

When preplanning for an incident, firefighters typically assess the facility and its related hazards. We are aware that industrial facilities are often large and contain many hazards. Preplans must consider the required fire flows and the industrial fire protection system that will help achieve that goal. Below, we consider fire protection water beyond the traditional municipal water supply and hydrants. Regarding supply, how much will we need and where will we get it from? We should answer these questions by preplanning and training well before the incident. As an organization responsible to respond to industrial facilities, we must preplan and learn about the unique aspects of the facilities and the challenges we may face.

The fire service likes the mantra of “big fire, big water.” We can typically meet the big water flows at a residential structure, but in an industrial incident, are we prepared for a fire flow rate greater than 5,000 gallons per minute (gpm)? Boat And Hose

Fire Protection Water Supply in the Industrial Environment - Firefighting

When the fire service arrives on the scene of a large-scale industrial incident, we must quickly establish a water supply officer. For many suburban and urban departments, a water supply officer is not part of a typical arsenal. Establishing water supplies beyond our hydrants is outside our comfort zone.

Beginning with water supply, are there dedicated fire protection water tanks? This raises several questions. Are they dedicated tanks, or is the water in the tank used for another purpose? For example, the facility may need 500,000 gallons of dedicated fire protection water. Common practice would be to build a 750,000-gallon tank; the top 250,000 gallons is available for plant service water to support the facility’s operations. In this case, the tank has two suction lines, one at the top to access the service water, and one at the bottom to supply the fire protection loop. This system’s advantage is that if the tank is completely full, there is an additional 50 percent of water available because we will have access to the service and the fire protection water. The disadvantage is that as fire protection systems are using the water from the tank, the service water will be used first. The service water may be used for critical systems, prompting a shutdown of the systems because of a lack of water. Facility operators are thus challenged with managing the fire and managing the safe continued plant operations or shutting down the facility.

The fire service must consider that a dedicated fire protection water tank is designed for a fire flow—e.g., the largest-demand sprinkler system and 500 gpm for handlines for two hours. However, if the largest-demand sprinkler is 1,500 gpm with an additional 500 gpm for handlines, the total flow is 2,000 gpm; this flow would need to be sustained for two hours. The dedicated fire protection water supply would be 240,000 gallons. This calculation is based on a single system activation flowing at its calculated flow; this could be between eight and 15 sprinklers. If more sprinklers than that are flowing because of a larger-than-anticipated fire, that flow could be greater.

The unfortunate reality is that typically industrial events escalate to multiple events within a facility. Activating multiple sprinkler systems or implementing master stream devices will deplete the water supply at an accelerated rate. In these cases, the incident command team must quickly identify alternative means for water supply.

Alternative water supplies may be taking water from other water tanks on site. These tanks may contain raw water, untreated and dirty, similar to drafting out of a lake or river. It may be treated potable water. In extreme cases, we may have to take water from tanks that supply industrial processes; the water may be ultra-pure. Using process water will affect the facility’s ability to remain online and require a shutdown.

(1) Removing the nozzle from the deck gun can provide an additional pump outlet to address the large demand for water at an industrial facility. (Photos by author.)

Note that most industrial facilities will continue production even during a fire because shutdowns and startups are time-consuming and costly. Depending on the facility’s size, a fire may affect a portion of the operation while the balance of the plant remains operational. In preincident planning, we must determine how we will access the water in the nonfire protection water tanks. The facility may have tanks connected together using crosstie valving. If so, we need to identify which valves must be opened to allow the tanks to cross tie. Otherwise, we might be able to connect the tank directly to the apparatus. When connecting an apparatus to a tank, we must identify what connections and adapters are needed to make the connection. We must use hard suction hose to make the connection because of the lack of significant head pressure to take suction through soft suction hose.

In industry, tank capacity is typically measured in feet. For example, if the tank is 36 feet tall in the interior, the tank gauge would read 36 feet, not 100-percent capacity or the capacity in gallons. Operators can quickly do the math to calculate how many gallons are in a foot based on the tank size. To illustrate our previous example, in the case of our 750,000-gallon tank that contains 250,000 gallons of service water and 500,000 gallons of fire protection water, the suction for the service water would be approximately at the 24-foot mark. This would only allow the use of the top 12 feet of the tank for service water. The suction line for the fire protection water would be close to the bottom, allowing the use of the entire tank capacity for fire protection.

Tank condition could be a factor too with low suction points. If the tank is not maintained or contains raw water with sediment, this could make it problematic as a reliable suction point. Some fire protection tank draft points may be several feet above the tank’s bottom to reduce the risk of drafting sediment into the system; however, the fire protection system will not be able to use 100 percent of the fire protection water.

Fire pumps are the next component of the fire protection water system; one or more of them push the water through the fire protection grid. The fire service must work with the facility to identify pump house locations. How are the pumps activated? Typically, a pressure drop activates the pumps, but if they do not start, how do we start them manually? We can remote start from a computer terminal in the control room or directly at the pump itself.

Are the fire pumps electric or fuel supplied? For electric pumps, is there a backup system to supply the pumps if power is lost? In the early 2000s, I was part of a firefighting crew at an electric generating facility that caught fire. The fire protection pump was electric. Unfortunately, during this incident, the facility lost all power and consequently lost its hydrant grid and sprinkler systems because the electric fire pumps were nonoperational. This utility now uses a combination of electric and diesel fire pumps for continuity and fire protection system redundancy.

For a fuel-supplied fire pump, how long can the pump operate before it needs to be refueled? For example, with diesel fire pumps, we may find a day tank in the pump house that is designed to operate the fire pump for eight hours when the tank is 100-percent full before refueling. The code allows for a ¾ tank of fuel. Is there sufficient fuel to run the pump for eight hours? If the incident lasts more than eight hours, the incident command team must determine how to refuel the tank before it runs out of fuel.

Fire pumps can be remotely operated but can only be turned off at the control panel at the fire pump. Fire pumps also do not recognize an interruption in water supply. If the water supply is lost to the pump, the pump will continue to operate until it is shut down manually or the pump fails. When a fire protection tank feeds the fire pumps, the water supply officer must monitor the tank level to prevent the pumps from running dry, cavitating the pump, and doing irreversible damage. Through preplanning, the fire department must know the installed fire pumps’ pumping capacity. Fire apparatus may create an overdemand on the flow and risk cavitation.

Once the water has left the pumps, it is distributed through the fire protection grid, which can include hydrants, large-diameter manifolds, fixed monitor nozzles, standpipes, and sprinkler systems. During preplanning, the fire service must identify what is on the fire protection system grid and the grid’s operating pressure.

The day-to-day operating pressure of the industrial hydrant loop may be relatively low. This is especially true in aging industrial facilities where the underground piping is reaching the end of its life span and needs maintenance. The fire service must identify how to increase the pressures on these systems during an emergency. Furthermore, we must identify what the operating pressures will be during an emergency. For example, in a power plant with which I have experience, the hydrant loop is part of the service water system. On any typical day, the hydrants will have a pressure of greater than 200 psi. Firefighters must know and have a plan to overcome the pressure in an emergency.

Many industrial facilities do not use potable water in their fire protection loop. Do not allow your firefighters to ingest the water! In the typical municipal system, the hydrants are part of the drinking water system, so it’s not uncommon to see firefighters cup their hands under a leaking hose connection to splash some water on themselves or get a drink. For example, a refinery may collect the water runoff and use that untreated runoff as part of the utility water system. The water may be less than clear and have a slight petroleum smell.

Just as we preplan the hydrant locations in the municipal setting, we must identify where the closest hydrants are in the industrial setting. Are all the hydrants part of the facility’s systems or are there also municipal system hydrants on site or nearby? How many hydrants will we need to meet the intended fire flow? Is the hydrant loop even designed for fire apparatus to hook to the system?

Some facilities have fire loops intended only for hose connections, not for fire apparatus. Are they all on the same loop or are there separate loops? We must preplan the hydrant grid and determine whether the system is a loop or has isolation valves for service. The loop will have a higher flow with the loop in service and a much lower flow when only fed from one side.

(2) Not all fire apparatus carry a large-diameter siamese.

(3) Adding double females to the traditional outlet side of a gated wye will change the gated wye into a siamese.

If an isolation valve is closed, are the fire protection systems shut off? The plants will operate with a known impairment on part of the system. Sometimes, these are reported to the insurance companies for approval if the risk is too high. A system could be knowingly shut off. The fire department will need to coordinate this.

A fire protection system feature found in industry that is similar to a hydrant is a large-diameter manifold, which is essentially a water main that comes out of the ground and has a series of large-diameter connections. This manifold is essential when supplying multiple large-diameter hoselines.

Large facilities may have a fire brigade with fire apparatus. Get to know the capacities of the apparatus. Industrial fire apparatus are designed to pump as much as 5,000 gpm from draft, dwarfing the pump capacities of our municipal apparatus.

Regarding the supply line, what type of couplings is it equipped with? If it has incompatible couplings, do we have the appropriate adapters? What size supply lines do they operate? It is not uncommon to see 7¼- to 12-inch supply lines. A 7¼-inch hoseline has approximately twice the water delivery of five-inch supply line.

Ask the industrial facility if your organization can participate in training with its response members. Most facilities will gladly welcome the local response organizations to help preplan for an incident; they recognize the value of a unified response system to mitigate an emergency.

When using a municipal pumper to provide a water supply at an industrial facility, the driver operator may be challenged to employ unconventional tactics to maximize the water being pumped through the apparatus, such as using the deck gun as an additional outlet. The deck gun traditionally comes directly off the pump and is designed to provide a large volume of water. Disconnecting the deck gun nozzle and attaching a three-inch supply line changes the deck gun from a fire attack device to another three-inch discharge on the truck. In the absence of a 2½-inch to large-diameter siamese, a company can take a large-diameter gated wye and equip it with two double females and the gated wye now becomes a siamese.

In many suburban and urban communities, a water supply is as simple as attaching a large-diameter hose to a hydrant and taking what you get. Keep the supply line out of the middle of the street to allow for vehicle access. When establishing a water supply, you must take the time to establish a system that will sustain the operation. Consider the number of pumps and hoses you require to fulfil the proper fire flow requirements.

For a sustained foam operation, provide an accessway for moving foam totes in and out. If the required fire flow is 5,000 gpm with three-percent foam, you would be using 150 gpm of foam concentrate per minute, which would mean you will need to switch out a standard 330-gallon foam tote every two minutes. You will need space to stage foam totes.

Fuel consumption is another consideration. Many industrial fire brigades know their apparatus’ gallons per hour consumption rate. Industrial fires often require long sustained pumping operations during which the apparatus must be periodically refueled.

The water supply operation at an industrial facility fire can be complicated. To be successful, the fire service and the industrial facility must identify the key components and identify the fire flow needs. A water supply plan must be more than a plan; it must be practiced to identify any gaps. The day the incident occurs is not the time to try to figure out how everything works.

Fire Protection Water Supply in the Industrial Environment - Firefighting

Marine Holding Tank Hose Brian S. Gettemeier has served the past 26 of his 29 years in the fire service as a career firefighter with the Cottleville (MO) Fire Protection District, where he is an engine company captain. He has a bachelor’s degree in fire service management from Southern Illinois University and has numerous state certifications. Gettemeier teaches all-hazards classes for municipal and industrial organizations in Missouri and Illinois and will present at FDIC International 2023.