The equation EP = NP + FL + APP + ELEV is the basic equation every pump operator needs to calculate when operating the fire pump. Today, many pump panels have flow meters that allow the pump operator to match the readout on the pump panel with the gallon-per-minute (gpm) flow of the selected nozzle.
How do you calculate the flow rate of a pump?
Now for the flow formula: Multiply the pump Horsepower times 2178 (a constant value) and then divide by the Total Pressure Head in feet. So for the example with a 2 h.p. Each figure can be calculated using simple math. How the concepts are developed is explained below.
How do you calculate the size of a fire pump?
For example, if you have a 40,000-square-foot building that is all ordinary group 1, the calculation would be 1,500 x 0.15 (density) = 225 + 250 (hose demand) = 475 gpm total for the fire pump. If the structure has multiple hazards, the hazard with the highest gpm calculation dictates the pump size.
How does the fire flow calculator work?
The Fire Flow Calculator uses the IFC method based on your project parameters to quickly grab the baseline fire flow and duration, and make adjustments for sprinkler protection. Now you have extremely quick access to determine required fire flow, and the documentation to support your process.
How much pressure does a fire pump produce?
Every fire pump is rated for a particular flow rate and corresponding pressure. For instance, a pump might be rated to produce 200 GPM at 170 PSI. However, the actual flow rate a pump experiences can vary. For example, the flow rate can be very high if many fire sprinklers activate during a fire.
How do you calculate fire flow rate?
Fire flow = length X width ÷ 3 This formula is most easily applied if the estimated square footage of the entire structure is used to determine an approximate fire flow for the total structure and is then reduced accordingly for various percentages of fire involvement.
How is pump flow rate calculated?
Calculating the desired flow rate of your pump is quite easy. Let's say, you want to transport 300 litres of a fluid every 30 minutes, then your pump system has to transport 300/30 = 10 litres per minute or 0.167 litres per second. This is the desired flow rate, which is usually calculated before the installation.
What is the required flow rate necessary for the fire pump?
Fire pumps are required to operate at 150% of their rated flow. Therefore, it is not required to select a pump rated at the flow demand; this would result in an oversized pump. For instance, if the flow demand is 295 gpm, a 200-gpm-rated fire pump can technically supply that flow.
What is fire pump GPM?
Flow Ratings of Fire Pumps Ratings range from 25 gallons/minute to 5,000 gpm, but the most commonly used ratings are 250 gpm, 500 gpm, 750 gpm and 1,000 gpm. The flow rating of a stationary fire pump is not a direct limitation on its use. Fire pumps are allowed to be used beyond their rated flow.
What is flow rate of a pump?
Volume flow rate (Q), also referred to as capacity, is the volume of liquid that travels through the pump in a given time (measured in gallons per minute or gpm). It defines the rate at which a pump can push fluid through the system.
How do you calculate flow velocity of a pump?
1:489:31Pump CALCULATIONS, Flow rate, RPM, Pressure, Power, DiameterYouTubeStart of suggested clipEnd of suggested clipBy the division of the old flow rate divided by the RPM.MoreBy the division of the old flow rate divided by the RPM.
How do you calculate fire pump kW?
Hence the pump power calculation formula can be written as below,Pump Power P(kW) = q(m3/hr) x ρ(kg/m3) x g(m2/s) x h(m) x p(Pa) / 3600000.P(kW -Shaft) = P(kW) / ηHence the pump required power,
How fire pump capacity is calculated PDF?
3:376:52How to Calculate Fire Pump and Jockey Pump Capacity ... - YouTubeYouTubeStart of suggested clipEnd of suggested clipSure you touch base with the insurance carrier for a particular project as they may require higherMoreSure you touch base with the insurance carrier for a particular project as they may require higher square footage or density requirements depending on the job.
How do you calculate pump capacity?
Pump Hydraulic Power (ph) = (D x Q x H x9. Pump Hydraulic Power (ph) = (1000 x 0.005 x 65 x9. 87)/1000 =3KW. Motor/ Pump Shaft Power (ps)= ph / pe = 3 / 80% = 4KW. Required Motor Size: ps / me =4 / 90% = 4.5 KW.
How do you size a fire pump?
Fire pumps are typically sized by pressure range, therefore a 400 gpm pump with a revolutions per minute speed of 3,550 can deliver a rated pressure from 40 to 56 psi without increasing the size of the pump.
How do you convert GPM to HP?
VARIABLE. Fluid Pressure - P. Fluid Flow Rate - Q. Fluid Power in Horsepower - HP.WORD FORMULA WITH UNITS. (PSI) = Force (Pounds) / Area ( Sq. In.) GPM= Flow (Gallons) / Unit Time (Minutes) Horsepower = Pressure (PSIG) × Flow (GPM)/ 1714.SIMPLIFIED FORMULA. P = F / A. Q = V / T. HP = PQ / 1714.
How do you calculate the water tank capacity of a fire pump?
Capacity=volume V=π(r^2)h, where 'r' and 'h' are the radius of circular cylinder forming the tank. We may fix one of r and h, suitably based on existing constraints and choose the other by the above formula using the maximum volume V required.
How many gpm does a smooth bore tip discharge?
For example, a one-inch smooth bore tip will have a discharge of 210 gpm: 29.72 × 12 × 7.07 = 210 gpm.
What is a fire stream?
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.
How does friction loss affect fire?
In the fire service, friction loss is defined as the loss of energy in pressure whenever water runs through hoses, fittings, and appliances. As water runs through hose, it rubs against the lining of the hose, the couplings, and even itself. Each time this happens, friction causes the water to slow down. Pump operators need to compensate for this loss. As far as pump operators are concerned, there are two ways water flows through hoses. The first is laminar flow, which occurs with relatively low velocities. In a perfect world, the water would flow right through the hose and never encounter any obstacles to slow it down. In laminar flow, the water flows in parallel lines with the flow at the center moving at a greater velocity than at the edges and decreases further out toward the edges of the hose. Picture layers of water flowing on top of each other. In laminar flow, the layers move smoothly against each other all in one direction.
How to determine friction loss in hose?
The only true way to figure the amount of friction loss is to connect pressure gauges to each end of the hoseline, place the hoses in straight lines and on level ground, and subtract the difference. It is important to keep the hose and equipment in good working condition at all times to eliminate as much of the friction-causing problems as possible.
What happens when water leaves the fire nozzle?
After the water leaves the nozzle, the stream is also affected by nature in the forms of gravity and wind. The stream needs to be strong enough to overcome these factors. There has to be enough reach so the firefighters don’t have to be in the absolute hottest environment. If the stream falls short of the fire, it cannot extinguish the fire. If the stream isn’t capable of overcoming the wind, it may not be possible to place the water on the seat of the fire, where it is needed.
What is a smooth bore nozzle?
A smooth bore nozzle is simply a tube that narrows down to an opening with a specific inside diameter. As the water gets narrowed through the nozzle, it develops its smooth solid stream. In the late 1890s, John R. Freeman1 conducted experiments designed to define what a good solid stream is. He came up with four requirements that are still used today:
How much of the fire flow should be added to a building on fire?
Likewise, if exterior structures are being exposed to fire from the original fire building, 25 percent of the actual required fire flow for the building on fire should be added to provide protection for each exposure.
What happens when the fire flow capability of available resources exceeds the required fire flow?
If the fire flow capability of available resources exceeds the required fire flow, an aggressive interior attack on the fire can usually be made.
What causes water to be increased in a fire?
There may be unforeseen factors impacting on the situation, such as barriers that prevent the water from reaching the seat of the fire, or building contents that cause unexpected fire behavior. If control is not achieved within a reasonable period of time , the amount of water may have to be increased.
What is the fire flow in multistory buildings?
In multi-story buildings, if more than one floor in the building is involved in fire, the fire flow should be based on the area represented by the number of floors actually burning. For example, the fire flow for a two-story building of similar dimensions as the previous example would be:
What is the problem facing the initial incident commander at a fire scene?
A problem facing the initial incident commander at a fire scene is how much water will be needed for effective fire control. This information will impact on the incident in terms of determining needed resources and the implementation of tactical operations.
How many gpm is needed to control a fire?
The quick-calculation formula indicates that if the dwelling were fully involved, it would require 400 gpm to effectively control the fire. If only half of the building were burning, 200 gpm would suffice, and 100 gpm should be sufficient if one-fourth of the building were involved.
Is exposure a separate fire area?
If the exposure becomes involved in fire (either additional floors of a multi-story building or adjacent structures), the exposure (s) should then be treated as a separate fire area and calculated separately, then added to the required fire flow for the original fire area.
How to calculate mass flow?
which is pumped to the pipes. Then by the following formula the velocity can be calculated: Mass flow = Density * Velocity * Pipe Area
What is a fire stream?
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 ...
How big should a nozzle be for a hose?
As a general rule, the maximum nozzle diameter should not exceed one-half of the size of the hose to which it is attached--for example, a2½-inch handline should not have a smooth bore nozzle any larger than1¼ inches.
Why do large fires happen?
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 officer as well as the pump operator need to know the GPM flow from different nozzle tips to know how much fire each can extinguish.
What is the most common method used to determine fire flow?
There are many methods for determining fire flow. The most common cited in US circles include the Insurance Services Office (ISO) Method, Iowa State Method, and the Illinois Institute of Technology (IIT) Method.
How to verify fire flow?
The best way to verify fire flow for a location is to conduct a flow test at the site itself. This of course can be difficult to impossible for new-construction projects on virgin sites.
When did IFC remove sprinkler flow reductions?
The 2015 and 2018 edition of IFC removed the approval necessity for sprinkler flow reductions.
Why is fire flow important?
It's used as an aid to determine pipe size and arrangements to delivery water to a specific area. Fire Flow is important for emergency response at it is the total capacity of the system that the fire department has available for use in response to a fire. How Is Required Fire Flow Determined? In short - it depends.
What is the first step in this overall determination of water supply to a site?
The first step in this overall determination of water supply to a site is to determine the required fire flow.
What is the International Fire Code?
The International Fire Code, which is widely adopted in the US, only requires that an approved water supply "capable of supplying the required fire flow" be provided to buildings. This process will be explored in more detail here. . 1. Determine Baseline Fire Flow.
How much water is needed to suppress a fire?
First, determining the exact amount of water required to manually suppress a fire is dependent upon so many variables. The amount of water used could depend on the building size, hazard, outdoor conditions, speed of fire growth, fire department response time, whether the building is protected by sprinklers, and on and on.
What is the most important consideration in the decision to change out a pump?
The volumetric efficiency of a pump is one of the most important considerations in the decision to change out a pump or not.
What is the most financially significant decision you'll make as a hydraulic troubleshooter?
Replacing/repairing suspect components is one of the most financially significant decisions you'll make as a hydraulic troubleshooter.
Is it dangerous to test a hydraulic pump?
Testing a hydraulic pump, especially a fixed displacement pump, is potentially dangerous and should never be attempted without proper training and oversight with your specific pump.
Sprinkler system demand and the water supply curve
Every fire sprinkler system needs a reliable water supply. Usually, this means a municipal water connection, but NFPA 13 allows tanks, ponds, and wells to serve as water supplies as well ( 5.2 ).
Fire pump performance curves
Fire pumps are an essential part of any fire sprinkler system that requires them, making up the difference between the water supply and system demand. Plus, they are easily the costliest and most complicated single piece of equipment in a system. So if you’re a facility manager, it pays to know about your fire pump.
To size a fire pump, designers combine pump curves and water supply curves
Once engineers determine that a fire pump is needed, they have to pick one that’s the right size. The first consideration when sizing a fire pump is making sure that it’s big enough. In other words, a pump is only useful if it produces enough flow and pressure.
Fire pumps provide essential flow and pressure to sprinkler systems and standpipes
The hydraulic design of a water-based system is all about supply and demand. The water supply for a fire sprinkler system—usually a city waterworks—has a finite capacity, and the system demands a specific flow rate and water pressure to function correctly. So, if the water supply doesn’t meet system demand on its own, a fire pump may be necessary.
How to calculate power of motor?
As a note on the power method, some people feel more comfortable simply taking the ratio of actual amps to the motor nameplate (if one is still attached!) amps rating, then multiplying the result on motor rated power. In our example, if the motor rated amps were, say, 8.5-amps, and rated motor power 5-hp, we could then assume the actual power is 3.9 / 8.5 x 5 = 2.3-hp. This is close to the 2.6-hp value we derived earlier by using a power factor and motor efficiency assumption.
How many amps does a 5 HP 460V motor read?
In our example, a 5-hp 460-V motor is used and we actually read 450-V and 3.9-amps. A typical assumption of the product (EFF motor x PF) is 0.85, although a somewhat better value can be obtained if one is willing to spend some more time on research work.
How many gpm does a 2.6 HP line intersect?
This is slightly less than the expected 3.2-hp, meaning a straight horizontal line at 2.6-hp intersects the power curve at flow approximately 50-gpm, depending how accurately you eyeball the curve.
How many HP is a power curve?
The power curve indicates approximately 3.2-hp at the rated point. Power meters (kW-meter) are rarely available, with amps and volts being more commonly displayed at the control panel. Power can be calculated from these readings, although some assumptions of the power factor and motor efficiency would be required:
Do pumps have flow meters?
Direct flow reading is the most sure way, but most pumps do not have in-line flowmeters installed. Cutting into lines to install them is impractical and expensive. External (ultrasonic) meters are simple, but accuracy is limited due to difficulties in locating a good (HI approved) spot along the pipe of the real field installation.
Can a power curve be flat?
Instead, the shape of the power curve can be entirely different. It can rise, drop, or stay constant with flow, even making its shape so flat that it becomes difficult to distinguish the difference for a rather wide variation of flows. The bottom line is that each method has its own place, strength and limitations:
Does power factor require dirty?
The power (amps) method does not require one to "get dirty" around the pump replacing broken gauges, but inaccuracy of the power factor and motor efficiency is a drawback. (Reference power factor fundamentals presented by Joe Evans in "Power Factor: Electricity Behaving Badly (Part One)" ( Pump Ed 101, Pumps & Systems June 2007)
How many gpm is a fire pump?
For example, if you have a 40,000-square-foot building that is all ordinary group 1, the calculation would be 1,500 x 0.15 (density) = 225 + 250 (hose demand) = 475 gpm total for the fire pump.
What pressure is needed for a fire pump?
This is a factor because any high rise requires a pressure of 100 pounds per square inch (psi) at the top of the structure while flowing the rated gallons per minute (gpm) of the fire pump.
How many gpm pumps are needed for a standpipe?
For example, a building with two standpipes would require a 750-gpm pump (500 gpm for the first standpipe and 250 for the second), and a building with five standpipes would require a 1,000-gpm pump because that is the maximum allowed by NFPA 14.
How much pressure to use for a non high rise sprinkler?
A similar calculation can be used for a non-high rise, by changing the 100 psi to the end head pressure (15 – 50 psi, depending on the head). However, the friction loss and pipe sizing become an issue when doing this calculation, which is why most contractors and sprinkler designers use software.
How often do fire pumps run?
One other note on fire pump selection is that selecting pumps that have a higher rpm is not necessarily a misstep, because fire pumps only run once a week for a limited amount of time, so the length of life will be about the same for a 1,750 rpm pump as for a 3,500 rpm pump.
What is the last job parameter you need to size a fire pump?
The last job parameter you need in order to size the fire pump is the required flow for the systems the pump will be serving (sprinklers, standpipes, or other). For standpipe systems, this flow is related to the type and size of the structure the pump is protecting. In any case, the demand of the system will dictate the pressure and flow required.
What is a horizontal split case fire pump?
Horizontal split case pumps are also called double-suction fire pumps, because the water pathways direct water to both sides of the impeller. They are the most common type of fire pump on the market, partly because of the ratings available in this style of pump, typically 250 through 5,000 gpm.
