Fire Hose Guide," PMS 466, NFES 1308, Febbruary 1997, "Safety in Testing" )]?.YkXv Jb,=x97xtf^ Compute the friction loss for the supply line a. Transfer valve improperly set a. If you ever stretch a line from an engine to the second-floor bedroom as the nozzle firefighter with only one other person, you will discover instantly that you must learn to operate that nozzle without the luxury of a backup firefighter behind you to assist in countering nozzle reaction. FireDepartment.net strives to provide fire departments & firefighters with quality tools. Sometimes they are used to get 1 hand lines to the fire where the reach is too long for a pre-connect. requested information regarding the safest and most efficient method to counter When operating from a draft, be sure suction screens are kept clean, 1. <>/Metadata 368 0 R/ViewerPreferences 369 0 R>> Insufficient engine power a. Compute the friction loss for one line of 3 hose delivering 400 GPM a. Relief valve improperly set a. When it is necessary to supply a pre-piped waterway, there are some basic facts the FAE will have to know: 1. Our department primarily has three-person engine staffing. On most large fires, they are used for overhaul from 2 lines rather than laying longer and/or additional lines of 1. Discharge Pressure formula. Therefore, the suction hose should be removed and cleaned, 4. When the fire department connection (siamese) supporting a standpipe system is not usable; and the check valve below the fire department connection (siamese) is inoperative, the following procedure should be followed: 1. 15 x 4 = 60psi FL for the total lay 4. If there were two 1 lines each 600 feet in length, the discharge pressure would be 280psi and the engine would be running at excessive RPM for the job. It is necessary to supply the water to the pump inlets or aerial intake when by-passing the pump and supplying the total operation. endobj 0 <> Enter the friction loss calculation to the right each hose's GPM. Example: How many pounds of sandbags Unfortunately in their good intentions is a risky business of not only underpumping (pressure) but by design also undersupplying (volume) those firefighters entering the structure. Suction hose not submerged deeply enough a. Suction screen and impeller vanes fouled with debris a. Backwash of water from the pump through the impellers when the pump is stopped usually cleans the impeller vanes i. Debris on the pump suction screen however, usually remains in the suction hose and is immediately caught by the screen when pumping is resumed ii. On occasion however, trouble will show up in one form or another and even an experienced operator may have difficulty in locating and correcting it. 2 x 2 x 2 + 2 = 10 pounds FL for 100 feet of hose, 3. product or service to the exclusion of others that may be suitable. Add each appliance's friciton loss in the path PDP you are calculating and enter appliance friciton loss as "A" in the PDP formula. <>stream Try to keep supply lines under 300 feet 2. Bags wrapped in paper should be split open Using nozzle reaction parameters and a set minimum standard for volume, the rest of the process is relatively simple: Find nozzles that flow greater than 150 gpm with nozzle reactions near 60 pounds, and put them in the hands of firefighters for them to find their preference. 326-W, Whitten Building, 1400 Independence Avenue, SW, Washington, D.C. If the pump will deliver capacity with a different suction hose, it is reasonable to assume the liner on the former hose has become loosened, 6. Detecting air leaks a. Connect suction hose to the pump with a cap on the opposite end of the hose b. 30 pounds FL per 100 feet = 60 pounds total (disregard the second line), 4. This will five 400 GPM through each line. Incorrect timing ii. for the 1.25-inch-bore-diameter nozzle and 600 to 850 pounds for the 1-inch-bore-diameter As pump discharge pressure varies in response to changing discharge volumes, the reference pressure in the accumulator acts on a hydraulic cylinder which in turn actuates a rod connected to the throttle linkage thereby adjusting the engine speed. A centrifugal pump is designed for a specific duty and ordinarily will perform this duty satisfactorily over a long period of time. Others will sometimes add 5psi loss for each appliance (gated wye & reducer or inline t) the water passes through. As you can see, these contributing factors all conspire together, and that call for more water never comes. %%EOF EXAMPLE: 400 feet of 2 hose wyed to two 200 foot lines of 1 hose. At the end of 2005, following a full year trail period with a variety of nozzles, the preference of our firefighters was the 78-inch smooth bore with a flow of 161 gpm at 50 psi and a nozzle reaction of 60 pounds. stores sell fiberglass sandbags with an attached metal ring designed to tie When higher than normal lifts are involved or at high altitudes, larger hose is needed. The FAE decides to use two 100 foot lengths of 3 hose as feeder lines to supply the aerials siamese in the rear of the aerial. enter it beside each section of hose, and underline that number.>. The next step was to determine a target flow for our 1-inch attack lines, as it was clear from this initial test that we did not have one. pressure and then the nozzle reactive force. NP = [(400gpm)/(29.71 Once the supply line is full, there is no further movement of water. Relay to ladder truck pump operator (refer to relay operations) 20 EXAMPLE 1: It is necessary to supply a pre-piped aerial ladder. Locating air leaks Air leaks may frequently be detected by ear if the engine is stopped. reactive force. If the pump pressure drops below 30 pounds per square inch, the unit automatically disengages, thus protecting the engine as in the case of loss of prime. activities on the basis of race, color, national origin, sex, religion, The discharge port and hose butt supplying this line is or becomes warm, C. Lack of a drop in the residual pressure as read on the compound gauge as this line is charged a. All rights reserved. 3 0 obj In many cases, it is being discovered that, for the most part, the only true gain has been nozzle reaction, which simply equates to more work on the nozzle firefighter. can be rewritten to solve for the unknown, nozzle pressure: Nozzle Pressure = NP psi Each organization has their own procedures for determining Friction Loss. Ek@$W &*@:d4zL@300RX " As a rough rule of thumb, the lbf of nozzle reaction for a 100-psi nozzle is half of the gpm. Side-Mount and Top-Mount Pumper Delivered to the Ridgeway (NJ) Fire Company. When the water is started in the supply line, the outlet valve is opened fully to allow water to flow into the riser, 5. All that remains is to add either the Nozzle Pressure if supplying a deluge gun or 20psi for residual pressure if supplying another engine. Connect the pumper supply line to the discharge outlet using a double female adapter, 4. In this situation would you know what to do? A three-person engine company translates to a two-member first-due attack line. Put the right weapon in your operators handsit may not be the one with the greatest fire power. Labor required (Y}c5ZXQm1s]munO^|zw'||=_]>?N^\ {|j~upm].oi{90c.owl_mOv?rnw1O |w8=]/}nv/}}Oyq=-:O_.>dm}}yvhfu>xqo..l-;$&lysq}oOtvyw~}s}RM716umk`B~si}w?PU'8nOJNO9|F 89/? ra[A~2Sfcf `qN1mTJQvlOIhA_0 t A.r!$>ky!u06&e 100 + 80 + 20 = 200 pounds engine pressure 18 RULE OF THUMB for siamese of unequal size, but of equal length (2-3) 1-2 & 1-3. A nozzle firefighter struggling with a 185-gpm or 200-gpm nozzle, only operating it for 10 to 15 seconds at a time without fatiguing, who has poor stream movement is potentially ineffectively applying only 30 to 50 gallons to the fire environment at a time. 60 + 80 + 20 = 160 pounds engine pressure EXAMPLE: If, in the above lay, it was necessary to use a 2 and a 3 line, FL would be computed just a bit differently. Weak condenser or coil v. Sticking valves vi. The maximum time for priming for lifts of 10 to 15 feet should not exceed 30 seconds for 1250 GPM pumps or below; or 45 seconds for 1500 GPM pumps or above d. Lack of oil in the primer reservoir i. x 1.25²)]², The formula for nozzle reaction These are the situations you should know and share with your crew. Always doublecheck the weight. The following are some recommended procedures for obtaining good elevated streams: 1. with disabilities who require alternative means for communication of program Most combination nozzles are rated at 100 psi. formula is gallons per minute (gpm) = 29.71 D² NP¹/. 150 gpm at 50 psi fixed-gallonage fog: Nozzle reaction force of 54 pounds, 78-inch smooth bore, 161 gpm at 50 psi: Nozzle reaction of 60 pounds, 150 gpm at 75 psi fixed-gallonage fog: Nozzle reaction force of 65 pounds, 1516-inch smooth bore 185 gpm at 50 psi: Nozzle reaction force of 69 pounds. the Nozzle Reaction for a 1.25-inch-Bore-Diameter Nozzle, Calculating 20250-9410 or call (202) 720-5964 (voice and TDD). He has a bachelors degree in fire and emergency services administration and a Fire Officer designation form CPSE. Many organizations chose to leave hardware out of the Pump Discharge Pressure calculations (which is easiest). endobj When it becomes necessary for a pumper to deliver large quantities of water, a siamese operation will be needed. of Agriculture (USDA) prohibits discrimination in all its programs and EQUAL SIZE LINES 1. The following may prevent the pump from delivering its rated capacity: 1. Badly worn wear rings a. With the finding that our firefighters felt most comfortable handling about 50 pounds of nozzle reaction, we had a starting point. High points in the suction line (caused, for example, by running suction hose over a bridge railing) create air pockets which may case loss of prime ii. USDA is an equal opportunity Add 100 psi as NP in the Pump Discharge Pressure formula. with sand, tightening up the fastener, turning the bag upside down into a second Fire Engine Pump Discharge Pressure (PDP) is the pressure set at the pump to achieve the desired pressure at the nozzle furthest from the pump (while considering the change in elevation and friction loss). The vacuum will promptly decrease as shown by the vacuum gauge, 2. This device is equally effective with gasoline or diesel engines. endobj 4 x 4 x 2 + 4 = 36 pounds FL per 100 feet, 3. be positioned across and down the entire length of the hose, with more weight How To Applying water or oil to the suspected points may aid in detecting leaks. Worn parts in the priming valve may also allow air leakage h. High point in suction line i. reactive force. Circle each of the PSI friction loss values for every hose in that path. In our example we will use a wildland firefighting example. The engine would be running at a discharge pressure of 210 pounds. Follow the manufacturers recommendation for priming ii. Each hose pack has one 100 ft 1 supply line, one 100 ft 1 attack line, one 1 Gated Wye, one 1 to 1" reducer, and one 10-20 GPM combination nozzle. Double-bag by filling a bag The friction loss factor for pre-piped waterways will include the friction loss in the: 3. Worn fuel pump poor carbonation c. Also, if the engine is operated at higher than normal altitudes, the power may be too low i. for the interpretation or use of this information by other than its own Governor limiting engine speed v. Insufficient engine power, 3. For example, if you have 600 ft of 1" hose pumping 40 gpm, there is 144 psi friction loss, add the 100 psi nozzle pressure, 80 ft elevation (add 40 psi head pressure) and you are at 288 psi (without considering hardware). You can also see the side-by-side comparison of a 150-gpm-at-50-psi fog nozzle with a 100-psi automatic fog nozzle. The nozzles furthest from the fire engine are often the only ones being used (to work around the fire's edge) and the other nozzles are only used periodically if the fire flares up after the first pass. Assume that all nozzles are flowing at 20 GPM and the fire is burning atop a small hill (40 feet above the fire engine). Pressures should be approximately 50psi and should not exceed that recommended for the suction hose or pump. The suggestions listed below should be helpful. = [(gpm)/(29.71 x D²)]² Clutch slippage iii. 113 0 obj Does not apply to single stage pumps ii. Total the GPM from both 1 lines. You can learn more about Hardware Friction Loss. Over the past 15 to 20 years, an increasing number of firefighters and departments are beginning to question what has been gained by doubling our nozzle operating pressures. In some cases, it may be impossible to rearrange the suction hose to eliminate the high point, 1. 20 GPM for each open nozzle on the hose-lay, Use the picture to determine the GPM passing through each section of hose, The Friction Loss Tables those values (19.4 psi) and enter the sum as A in the Pump 1 0 obj This may be rounded off to 0.5 pounds per foot of elevation for fire ground calculations. FRICTION. Ask your trainer or supervisor how they want you calculate hardware friction loss. increased to 285 pounds reactive force. in either a plastic bag or a paper wrapper should be double-bagged with the Be sure to keep the end of the suction hose off the lake or river bottom, 2. (Not all prohibited bases apply to all programs.) The third principle of fluid pressure, Pressure applied to a confined fluid from without is transmitted in all directions without diminution. NOTE: Methods A and B may not be readily apparent or the best indication, especially if the pumper is supplying additional lines which are already flowing. NP +/- H + FL + A = PDP Provide enough space on the right side of formula to enter numbers and perform calculations. I have seen it time and time again where departments are training, purchasing, and writing policy for staffing that they do not have. If everyone has a short list of hazardous situation to look out for, if an inexperience firefighter must run the pump, they will be able to do so with a higher degree of safety due to this preperation. endobj The formula Chassis transmission in wrong gear a. Keep in mind, hose-lay hardware usually accounts for a very small percentage of friction loss on a hose-lay and no two types of hardware have the same friction loss. Reaction for a 1-inch-Bore-Diameter Nozzle Multiply the FL for 100 feet by the length of the lay in hundreds of feet a. Discharge valves or gaskets iii. If it is impossible to draw this much vacuum, the primer may be defective d. Close the priming valve and shut off the primer e. Shut off the engine i. % Add the two FL answers together and divide by two a. 23 a. Add NP, H, FL, and A to get the Pump Discharge Pressure (139.4 psi). See exhaust primer manufacturers operating instructions to remove carbon g. Defective priming valve i. There have been several studies done over the past 20 years into nozzle reaction and how it affects hoseline operations. Your crew has just deployed 3 Hose Packs on a small brush fire. 22. 21. A broken or deteriorated priming valve spring may cause the valve to leak and the pump to lose its prime. Compute the friction loss for one line of 2 hose delivering 400 GPM a. endstream Does not apply to singe stage pumps b. Deteriorated crank case oil e. Transfer valve improperly set i. age, disability, political beliefs, sexual orientation, or marital or The following are suggested methods to indicate if youre not getting into a sprinkler or standpipe system with a supply line. on Fire Apparatus," 1997. information (Braille, large print, audiotape, etc.) (NR) for sloid bore nozzles is NR = 1.57 D²NP It is necessary to know the size tip that is intended for use in order to calculate pressure, determine the number of lines required and their diameter Since the waterways on pre-piped aerials are made of pipe, the following constants are used to determine the friction loss in the piping, master stream at different gallon flows. With a Factor of Safety of 2 to 3, it in this document has been developed for the guidance of employees of the Capacity limiting pressure a. EXAMPLE: It is necessary to supply a deluge set with a 1 tip from 400 feet away. SIAMESE LINES TOTAL GPM FL PER 100 FEET 500 10 600 15 700 20 800 24 900 30 1000 40 WYE OPERATIONS Wye operations are very common and are used in one way or another on just about any fire of consequence. Enter 139.4 into your formula. Sufficient pressure is maintained The modern aerial ladder is a valuable piece of equipment of the department that uses it well. Valdosta (GA) Fire Department Purchases Demo Truck to Avoid Supply Chain RAE Systems Makes Toxic Gas Monitor Calibration Station. added at the nozzle end to secure it in place. If your pump shows output GPM, it is important to monitor water usage (for many reasons). Add 80 pounds NP to the 100 pounds FL + 20 pounds approximate FL in the deluge set a. The smooth bore nozzle may be viewed by some as dated, but if you take a little deeper look at history, you can see some very sound reasoning in the smooth bore nozzle. inside the double sandbag, allowing the sandbag to be pliable and drape over For the goal of the study, we wanted to establish 150 gpm as the minimum flow for any interior attack lines. What is key to remember is that nozzle ratings are just ratingswhen closed, all nozzles flow 0. Warn firefighters that nozzles near the pump may have an extremely high pressure. at a home improvement store cost approximately 25 cents each. The aerial is elevated 50 feet above grade on a 100 foot aerial with a 2 tip (1000 GPM). BRIAN BRUSH is a 20-year veteran of the fire service and a training division sergeant at Edmond (OK) Fire Rescue. This lay would require 800 GPM which would create 55 pounds FL per 100 feet in 3 hose; therefore, siamesing is necessary. 36 + 15 = 51/2 = 14.4 or 15 pounds FL per 100 feet of hose, 5. Hose with high pressure is more ridged/fragile and should be handled more gently. This number comes from National Fire Protection Association (NFPA) 1710, Organization and Deployment of Fire Suppression Operations by Career Fire Departments. Faulty pump packing c. Leaky pump gaskets All suction hose gaskets should be wiped clean of sand, pebbles and any other foreign matter before hose is attached to the pump. This type of nozzle essentially puts the flow rate in the hands of the pump operator and, in the absence of a set department standard, this becomes a very concerning unknown. Without those practices, nozzle reaction forces beyond 60 pounds typically begin to reduce the effectiveness of the single firefighter nozzle operator. <>stream , _S+ir4 ~QA0h&@;_+bM>nF=E{a x 3=}dXoft!fv4u*bv5Q[k{s'sG>jM The proper size tip or fog nozzle is used for the available water supply and pumping capacity, 2. 1. If 600 pounds of sandbags are used, the cost will be $28. On the nozzle reaction charts, you can see the amount of nozzle reaction associated with four very common 1-inch nozzles. Calculating the Nozzle If the pump is operating at draft under normal suction conditions and the maximum rated capacity is exceeded the pressure will be low due to the characteristic of a centrifugal pump even if the engine has plenty of power and speed c. Excess capacity may raise the suction vacuum to a point above that which the pump was designed and lowered pressures will result d. On pumping units having engines with low surplus power, the pressure will be limited by engine power if surplus capacity is being pumped 27. is recommended that 600 to 850 pounds of sandbags be used to counter the nozzle Look at the pressure (PSI) on the hoses with the highest friction loss to determine if it exceeds the maximum rating of the hose (300 psi when tested annually). Nozzle reaction x Factor Of Safety of 2 to 3. Divide the total GPM by two lines. endstream <>/Filter/FlateDecode/ID[<70EEB4D4C75A8A67836A89FF1434167B><4E3CC0AAD11DB2110A00FCF6C0B3A7FF>]/Index[110 28]/Info 109 0 R/Length 82/Prev 557779/Root 111 0 R/Size 138/Type/XRef/W[1 3 1]>>stream It is important to use the proper Burned distributor points iv. the hose nozzle reactive force generated during annual fire engine service testing. If the 1-inch hoseline is your departments 90 percent of the time and your engine company staffing is three members, you must identify what your firefighters are comfortable with regarding operating a line by themselvesit may be surprisingly less than you assume. All the calculations work the same for structure fires, vehicle fires and wildfires. The other member will almost always be working to tend the line through furniture, around corners, and up stairs somewhere between your location and the front door. 4 x 4 x 2 + 4 = 36 x 0.4 = 14.4 or 15 pounds of FL per 100 feet of hose 3. The following may prevent the pump from developing sufficient pressure: 1. 4. Where a mechanically driven or electrically driven rotary primer is in use, an adequate supply of oil should always be kept in the reservoir to lubricate and seal the priming pump e. Improper clearance in rotary primer i. should be used to counter the reactive force generated by a 1.25 inch-or a 1-inch-bore-diameter fire program leader by phone at (909) 599-1267, or by fax at (909) 592-2309. If a relief valve is set at a pressure below the desired operating pressure it will bypass water and lower the capacity (see manufacturers relief valve operating instructions), 2. Remove any house lines, reducer connections and/or pressure reducers, 3. 8. hZny(S$ r`)qF?X&@99=C2H.e]uqcE6;ol. x]Ys8~w&V4q$7sY}]H\ dZ*$2zWw}go|7n_^UORg7MuOzURU'Ud&>uW?ok?>yS8wn' CmTcynu}|UX/ MuF>}(37q^3BU!px67\V-LBlRwwm/>VnGSErky^{Q}KY 0C_70>]^t[?~AL`L@=XVG7 vVd.8#Fg9 yG|HT-Q\j.
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