Gpm formula firefighting

Gpm formula firefighting

Login or Sign Up. Logging in Remember me. Log in. Forgot password or user name? If you have a need to advertise on Firehouse. Post only in a mature and responsible way that contributes to the discussion at hand. Post in the correct forum and have clear titles for your threads.

Please post in English or provide a translation. There are moderators and admins who handle these forums with care, do not resort to self-help, instead please utilize the reporting option. Be mature and responsible for yourself and your posts. If you are offended by another member utilize the reporting option.

All reported posts will be addressed and dealt with as deemed appropriate by Firehouse. User s whose posts are determined by Firehouse. An initial warning will be issued. A Final Warning will be issued if a user is found to be in violation a second time. A 3-day suspension will be issued if the user continues to break the forum rules.

A day suspension will be issued if the user is found to be a habitual rule breaker. Habitual rule breakers that have exhausted all of the above will receive a permanent life-time ban that will be strictly enforced.

Reinstatement will not be allowed — there is no appeal process. Subsequent accounts created in an effort to side-step the rules and moderation process are subject to automatic removal without notice. Any user in the moderation process may be required to review and agree to by email the terms and conditions listed above before their account is re-instated except for those that are banned.

Please ensure your posts are tasteful and tactful. Thank you very much for your cooperation. GPM Formulas. Posts Latest Activity. Page of 1. Filtered by:. Previous template Next.About Ed Hartin. Application of the appropriate flow rate is critical to fire control.

However, how can we estimate the flow rate that is necessary? There are a number of methods that can be used to estimate or calculate required flow rate for fire control. One method is to simply use your experience which may work quite well if you have been to a large number of fires and paid attention to flow rate.

However, if you do not have a large base of experience to draw on or need to apply flow rate estimation in a preplanning context, other methods are necessary. In the mid s the development team for the National Fire Academy Field course Preparing for Incident Command developed this formula to provide a simple method for estimating the flow requirements for offensive, interior operations where a direct attack was used to control and extinguish the fire.

The developers tapped into another valid source of information, knowledge of experienced fire officers. The course developers designed a number of plot and floor plans showing different sizes of building with different configurations e. These drawings were distributed to students attending the academy and they were asked how their fire department would control the fire with the emphasis on the number, placement, and flow rate of hoselines.

For each scenario, when the floor area of the involved area in square feet ft 2 was divided by the total flow rate in gallons per minute gpm for all hoselines used for attack, backup, and exposure protection; the average result was three.

gpm formula firefighting

Turning this around, flow rate in gpm can be determined by dividing the area of involvement in ft 2 by three. In that the exterior of the building can be determined more easily than the area of involvement, the formula was adapted to determine the flow rate based on building size and approximate percentage of involvement as illustrated below:. The full formula as used in preplan development is as follows:. However, this was not validated using the same type of methodology as used to develop the base fire flow formula.

The most common application error is the belief that the formula determines the flow rate required for fire attack. This is incorrect! The formula determines the total flow rate required for attack, backup, and exposure protection lines. Use of this formula to determine the flow rate for the initial attack line or lines will greatly overestimate the required tactical rate of flow.

If excessive, water that is not used efficiently i. Using the NFA Base Fire Flow Formula no exposuresroughly half of the flow rate is used for attack lines and the remainder is used for backup lines. The NFA formula provides an excellent method for estimating total flow rate requirements which impacts on water supply and resource requirements. However, it must be adjusted reduced by half to determine the tactical rate of flow necessary for direct attack on the fire. As outlined in this post, the NFA Fire Flow Formula is intended for estimating the total flow rate required when making a direct attack and has a number of specific parameters that must be considered.

Bill Nelson and Keith Royer. The Iowa Formula was developed quite differently, has substantially different assumptions, and will be the subject of my next post. Paul has amassed a tremendous amount of information on this topic from around the world. Development of the NFA Formula In the mid s the development team for the National Fire Academy Field course Preparing for Incident Command developed this formula to provide a simple method for estimating the flow requirements for offensive, interior operations where a direct attack was used to control and extinguish the fire.

There are three major parameters used for the scenarios based on these plot and floor plans. Operations were to be conducted as they normally would, with initial operations started by the first arriving company and additional tactics implemented as resources arrive. Primary search and ventilation tactics would be performed concurrently with fire control operations.Make FireRescue1 your homepage.

There are two ways to calculate friction loss: the theoretical method or the fireground method — here's the fireground method. There are plenty of things that the pump operator must get done in the early stages of a fire, and none are more important than this.

To determine this, the pump operator must first know the total gallons per minute flow, that is, the desired result on the working end of the hose. The type of nozzle being used — smooth-bore, automatic nozzle or adjustable gallonage — will determine the gpm.

Pump Discharge Pressure Calculations

Once the pump operator knows what the desired gpm is, then they must know what size hoses are being used, the lengths of the hoses and any appliances that are part of the hose layout, such as a gated wye. Armed with that information, the pump operator can then calculate the friction loss, the remaining ingredient for getting the right mixture to their firefighting colleagues.

Friction is the force resisting the relative motion of solid surfaces, fluid layers and material elements sliding against each other.

Friction loss is the pressure loss due to the friction. In its fire service application, the friction is water sliding against the interior surfaces of the pump, any connected appliances — gated wyes, manifolds or a water thief — standpipes and fire hose.

In reality, understanding friction loss and its place in properly supplying hose lines and fire streams is not that daunting of a task. The basic challenge for the pump operator is to develop the proper pump discharge pressure necessary to overcome the friction loss in a fireground set up to ensure that the firefighter on the nozzle will have the appropriate amount of water to suppress the fire.

There are two ways to calculate friction loss: the theoretical method or the fireground method. Theoretical calculations are generally best used for pre-fire planning, developing specifications for pumping apparatus and calculating problems ahead of time, such as creating pump charts. Theoretical calculations are typically not an efficient means of calculating friction loss on fire scenes.

Many times, instructors teaching pump operations bring out the theoretical method, along with its equations, at the beginning of the training process. I was very fortunate at the beginning of my firefighting career to join a department where that was not the case.

My pump operator instructors focused early on developing my skills in using such tools as the hand method for calculating friction loss. They also emphasized memorizing the friction loss for the pre-connected hand lines and typical hose layouts that I would encounter as a pump operator. This is an extremely valuable tool for both learning and teaching what the friction loss is for various sizes of hose and various gpm flows. Below is one example of a hand method for calculating friction loss in various sizes of hose.

For a 3-inch supply line flowing gpm, the friction loss per foot section would be 9 psi: 3 squared equals 9 psi. Memorizing this much simpler than it sounds. All you must remember is the friction loss for each, 14, 24, 35 and 62, respectively. Those are the amounts of friction loss per feet of hose based on the gallonages above. Change the flow setting on the nozzle to gpm on the same foot line and the friction loss is 35, if you increase the hose length to feet, the friction loss becomes 62 psi.

To figure the required discharge pressure, add up all friction loss — in the hose and any appliances — plus the required nozzle pressure. Thus, for that apartment complex layout I mentioned earlier, the calculation would look like this:. Do your homework about the different hose loads, appliances and nozzles used in your department and what each contributes to friction loss, that is, what are the friction loss points.

A best practice employed by many skilled pump operators is creating a cheat sheet containing what those friction loss points look like. Source: University of Alaska, Fairbanks.Register now or log in to join your professional community. There are two main factors in GPM calculations: 1. Area calculation according to hazard type :-The density is multiplied by for light and ordinary and for extra hazard a Light hazard- density 0.

So for the example with a 2 h. Each figure can be calculated using simple math. How the concepts are developed is explained below. The engine pressure is calculated by plugging numbers into each figure and adding or subtracting them. Products By Bayt. Use Our Mobile App. Get Fresh Updates On your job applications, and stay connected. Download Now. Start networking and exchanging professional insights Register now or log in to join your professional community.

Follow How to calculate GPM water flow for a fire pump? What are the procedures? Upvote 0 Views Followers 8. Write an Answer Register now or log in to answer. Upvote 5 Downvote 0 Reply 0. Upvote 4 Downvote 0 Reply 1.

Upvote 0 Downvote 0 Reply 0. This nozzle gives the stream its shape, reach, and velocity. By definition, a fire stream is a stream of water after it leaves the nozzle until it reaches its final destination, which is usually the seat of the fire. As the streams are being produced, they are affected by the discharge pressure, nozzle design, and nozzle setting.

The officer in charge of a fire needs to determine the amount of water needed to extinguish the fire and choose the appropriate hoseline and nozzle that will deliver the correct GPM.

Large fires make for good news coverage, but in reality they happen because the firefighters were unable to place enough water at the seat of the fire to overcome the Btus being produced.

The amount of water discharging from a smooth bore is determined by the nozzle pressure and the inside diameter of the opening. The formula for determining the GPM flow from a smooth bore nozzle is as follows:. Answer added by hifzoor qureshi 2 years ago. See More Answers.There are plenty of things that the pump operator must get done in the early stages of a fire, and none are more important than this.

Posts Tagged ‘NFA fire flow formula’

To determine this, the pump operator must first know the total gallons per minute flow, that is, the desired result on the working end of the hose. The type of nozzle being used — smooth-bore, automatic nozzle or adjustable gallonage — will determine the gpm. Once the pump operator knows what the desired gpm is, then they must know what size hoses are being used, the lengths of the hoses and any appliances that are part of the hose layout, such as a gated wye.

Armed with that information, the pump operator can then calculate the friction loss, the remaining ingredient for getting the right mixture to their firefighting colleagues. Friction is the force resisting the relative motion of solid surfaces, fluid layers and material elements sliding against each other. Friction loss is the pressure loss due to the friction.

In its fire service application, the friction is water sliding against the interior surfaces of the pump, any connected appliances — gated wyes, manifolds or a water thief — standpipes and fire hose. In reality, understanding friction loss and its place in properly supplying hose lines and fire streams is not that daunting of a task. The basic challenge for the pump operator is to develop the proper pump discharge pressure necessary to overcome the friction loss in a fireground set up to ensure that the firefighter on the nozzle will have the appropriate amount of water to suppress the fire.

There are two ways to calculate friction loss: the theoretical method or the fireground method. Theoretical calculations are generally best used for pre-fire planning, developing specifications for pumping apparatus and calculating problems ahead of time, such as creating pump charts.

Theoretical calculations are typically not an efficient means of calculating friction loss on fire scenes. Many times, instructors teaching pump operations bring out the theoretical method, along with its equations, at the beginning of the training process. I was very fortunate at the beginning of my firefighting career to join a department where that was not the case. My pump operator instructors focused early on developing my skills in using such tools as the hand method for calculating friction loss.

They also emphasized memorizing the friction loss for the pre-connected hand lines and typical hose layouts that I would encounter as a pump operator.

This is an extremely valuable tool for both learning and teaching what the friction loss is for various sizes of hose and various gpm flows. Below is one example of a hand method for calculating friction loss in various sizes of hose.

For a 3-inch supply line flowing gpm, the friction loss per foot section would be 9 psi: 3 squared equals 9 psi. Memorizing this much simpler than it sounds. All you must remember is the friction loss for each, 14, 24, 35 and 62, respectively. Those are the amounts of friction loss per feet of hose based on the gallonages above.

Change the flow setting on the nozzle to gpm on the same foot line and the friction loss is 35, if you increase the hose length to feet, the friction loss becomes 62 psi. To figure the required discharge pressure, add up all friction loss — in the hose and any appliances — plus the required nozzle pressure.

Thus, for that apartment complex layout I mentioned earlier, the calculation would look like this:. Do your homework about the different hose loads, appliances and nozzles used in your department and what each contributes to friction loss, that is, what are the friction loss points. A best practice employed by many skilled pump operators is creating a cheat sheet containing what those friction loss points look like. Source: University of Alaska, Fairbanks. The Physics of Fireground Hydraulics.

April My fire service colleague with the Henrico County Va. Division of Fire, Taylor Goodman, offers another perspective on friction loss.Login or Sign Up. Logging in Remember me. Log in. Forgot password or user name? If you have a need to advertise on Firehouse. Post only in a mature and responsible way that contributes to the discussion at hand.

Post in the correct forum and have clear titles for your threads. Please post in English or provide a translation. There are moderators and admins who handle these forums with care, do not resort to self-help, instead please utilize the reporting option.

Be mature and responsible for yourself and your posts. If you are offended by another member utilize the reporting option. All reported posts will be addressed and dealt with as deemed appropriate by Firehouse. User s whose posts are determined by Firehouse. An initial warning will be issued. A Final Warning will be issued if a user is found to be in violation a second time. A 3-day suspension will be issued if the user continues to break the forum rules.

A day suspension will be issued if the user is found to be a habitual rule breaker. Habitual rule breakers that have exhausted all of the above will receive a permanent life-time ban that will be strictly enforced. Reinstatement will not be allowed — there is no appeal process. Subsequent accounts created in an effort to side-step the rules and moderation process are subject to automatic removal without notice. Any user in the moderation process may be required to review and agree to by email the terms and conditions listed above before their account is re-instated except for those that are banned.

Please ensure your posts are tasteful and tactful. Thank you very much for your cooperation. This topic is closed. Posts Latest Activity. Page of 1. Filtered by:. Previous template Next. Larry Welle. Flow rate equals 10 gpm for same problem as above.

Tags: None. It is length x width x of floors all divided by 3 for a structure that is fully involved. I hope this helps.

gpm formula firefighting

Comment Post Cancel. Plus multiply by the number of floors.Make FireRescue1 your homepage. There are two ways to calculate friction loss: the theoretical method or the fireground method — here's the fireground method. There are plenty of things that the pump operator must get done in the early stages of a fire, and none are more important than this.

To determine this, the pump operator must first know the total gallons per minute flow, that is, the desired result on the working end of the hose.

How to calculate GPM (water flow) for a fire pump? What are the procedures?

The type of nozzle being used — smooth-bore, automatic nozzle or adjustable gallonage — will determine the gpm. Once the pump operator knows what the desired gpm is, then they must know what size hoses are being used, the lengths of the hoses and any appliances that are part of the hose layout, such as a gated wye. Armed with that information, the pump operator can then calculate the friction loss, the remaining ingredient for getting the right mixture to their firefighting colleagues.

Friction is the force resisting the relative motion of solid surfaces, fluid layers and material elements sliding against each other. Friction loss is the pressure loss due to the friction. In its fire service application, the friction is water sliding against the interior surfaces of the pump, any connected appliances — gated wyes, manifolds or a water thief — standpipes and fire hose. In reality, understanding friction loss and its place in properly supplying hose lines and fire streams is not that daunting of a task.

The basic challenge for the pump operator is to develop the proper pump discharge pressure necessary to overcome the friction loss in a fireground set up to ensure that the firefighter on the nozzle will have the appropriate amount of water to suppress the fire.

There are two ways to calculate friction loss: the theoretical method or the fireground method.

gpm formula firefighting

Theoretical calculations are generally best used for pre-fire planning, developing specifications for pumping apparatus and calculating problems ahead of time, such as creating pump charts. Theoretical calculations are typically not an efficient means of calculating friction loss on fire scenes. Many times, instructors teaching pump operations bring out the theoretical method, along with its equations, at the beginning of the training process.

I was very fortunate at the beginning of my firefighting career to join a department where that was not the case. My pump operator instructors focused early on developing my skills in using such tools as the hand method for calculating friction loss.

They also emphasized memorizing the friction loss for the pre-connected hand lines and typical hose layouts that I would encounter as a pump operator. This is an extremely valuable tool for both learning and teaching what the friction loss is for various sizes of hose and various gpm flows. Below is one example of a hand method for calculating friction loss in various sizes of hose.

For a 3-inch supply line flowing gpm, the friction loss per foot section would be 9 psi: 3 squared equals 9 psi. Memorizing this much simpler than it sounds. All you must remember is the friction loss for each, 14, 24, 35 and 62, respectively. Those are the amounts of friction loss per feet of hose based on the gallonages above.

Change the flow setting on the nozzle to gpm on the same foot line and the friction loss is 35, if you increase the hose length to feet, the friction loss becomes 62 psi. To figure the required discharge pressure, add up all friction loss — in the hose and any appliances — plus the required nozzle pressure. Thus, for that apartment complex layout I mentioned earlier, the calculation would look like this:. Do your homework about the different hose loads, appliances and nozzles used in your department and what each contributes to friction loss, that is, what are the friction loss points.

A best practice employed by many skilled pump operators is creating a cheat sheet containing what those friction loss points look like. Source: University of Alaska, Fairbanks. The Physics of Fireground Hydraulics. April My fire service colleague with the Henrico County Va.

gpm formula firefighting

Comments

Leave a Reply

Your email address will not be published. Required fields are marked *