Pumping Apparatus Driver/Operator 12–1 Learning Objectives 1.Match to their definitions terms associated with static water sources. 2.Select facts about theoretical, maximum, and dependable lift. 3.State the equation for determining the maximum lift that a pumper can achieve. (Continued)
Pumping Apparatus Driver/Operator 12–2 Learning Objectives 4.Calculate maximum lift. 5.State the equations for determining pressure correction and net pump discharge pressure at draft. 6.Calculate net pump discharge pressure at draft. (Continued)
Pumping Apparatus Driver/Operator 12–3 Learning Objectives 7.List types of natural static water supply sources. 8.State the equation for determining the adequacy of a natural stream. 9.Calculate natural stream adequacy. 10.Answer questions about the accessibility of natural static water supply sources. (Continued)
Pumping Apparatus Driver/Operator 12–4 Learning Objectives 11.Dam a stream with a ladder and salvage cover. 12.List common types of man-made static water supply sources. 13.Select facts about various man-made static water supply sources. (Continued)
Pumping Apparatus Driver/Operator 12–5 Learning Objectives 14.State the equations for determining the capacity of various kinds of pools. 15.Calculate swimming pool capacities.
Pumping Apparatus Driver/Operator 12–6 Static Water Source Terms Drafting — Raising water from a static source to supply a pumper Lift — Elevation difference between static water source and pump intake (Continued)
Pumping Apparatus Driver/Operator 12–7 Static Water Source Terms Vacuum — The pressure differential between the inside of the pump and intake hose and the atmosphere that allows water to be forced into the hose and pump Theoretical lift — Vacuum that would allow water to be raised by atmospheric pressure to a height in accordance with this pressure (Continued)
Pumping Apparatus Driver/Operator 12–8 Static Water Source Terms Maximum lift — The maximum height to which any amount of water may be raised through a hard intake hose to the pump Dependable lift — The height a column of water may be lifted in sufficient quantity to provide a reliable fire flow
Pumping Apparatus Driver/Operator 12–9 Theoretical Lift Customary — At sea level a pump can theoretically lift water 33.8 feet. For every 1,000 feet of altitude, atmospheric pressure decreases by about 0.5 psi. Metric — At sea level a pump can theoretically lift water 10 m. For every 100 m of altitude, atmospheric pressure decreases by about 1 kPa. (Continued)
Pumping Apparatus Driver/Operator 12–10 Theoretical Lift Because a total vacuum is not possible in field conditions, fire department pumpers cannot be expected to draft water that is located 33.8 feet (10 m) below the level of the pump.
Pumping Apparatus Driver/Operator 12–11 Maximum Lift Varies depending on the atmospheric pressure and the condition of the fire pump and primer Is no more than 25 feet (7.5 m) in most circumstances
Pumping Apparatus Driver/Operator 12–12 Calculating Maximum Lift Customary L = 1.13 Hg L = Height of lift in feet 1.13 = A constant Hg = Inches of mercury (Continued)
Pumping Apparatus Driver/Operator 12–13 Calculating Maximum Lift Metric L = ( )(Hg) L = Height of lift in meters = A constant Hg = mm of mercury
Pumping Apparatus Driver/Operator 12–14 Dependable Lift Every fire pump in good repair should have a dependable lift of at least 14.7 feet (4.5 m). This takes into account: –Surrounding atmospheric pressure –Friction loss in the intake hose (Continued)
Pumping Apparatus Driver/Operator 12–15 Dependable Lift All fire pumps are rated when drafting from a lift of 10 feet (3 m) through 20 feet (6 m) of hard intake hose. As the lift or length of intake hose is increased, the capacity of the pump decreases accordingly.
Pumping Apparatus Driver/Operator 12–16 Determining Pressure Correction Customary Pressure correction = Lift + Total intake hose friction loss 2.3 Metric Pressure correction = Lift + Total intake hose friction loss 0.1
Pumping Apparatus Driver/Operator 12–17 Determining Net Pump Discharge Pressure at Draft NPDP Draft = PDP + Intake pressure correction NPDP Draft = Net pump discharge pressure at draft PDP = Pump discharge pressure in psi or kPa
Pumping Apparatus Driver/Operator 12–19 Adequacy of Natural Static Water Supply Source The adequacy of large sources is generally not a major issue. However, fire department personnel must evaluate small streams and ponds with more caution when determining their adequacy for fire protection.
Pumping Apparatus Driver/Operator 12–20 Calculating Natural Stream Adequacy Customary Q = A x V x 7.5 Q = Flow in gpm A = Area in ft 2 (width x depth) V = Velocity in ft/min 7.5 = A constant (the number of gallons per ft 3 ) (Continued)
Pumping Apparatus Driver/Operator 12–21 Calculating Natural Stream Adequacy Metric Q = A x V x Q = Flow in L/min A = Area in m 2 (width x depth) V = Velocity in m/min 1 000= A constant (the number of liters per m 3 ) (Continued)
Pumping Apparatus Driver/Operator 12–22 Calculating Natural Stream Adequacy The rule of thumb for evaluating pond and small lake capacity is that every 1 foot (0.3 m) of depth of an area of 1 acre (0.4 ha) (approximately the size of a football field) provides 1,000 gpm (4 000 L/min) for 5 hours.
Pumping Apparatus Driver/Operator 12–23 Accessibility of Natural Static Water Supply Sources Common problems include: –Inability to reach the water with a pumper –Wet or soft ground approaches –Inadequate depth for drafting –Silt and debris –Freezing weather
Pumping Apparatus Driver/Operator 12–24 Inability to Reach the Water with a Pumper Bridges too high above the water’s surface Bridges that will not support the weight of the fire apparatus Extremely high banks Terrain that will not allow the apparatus close enough to reach the water with intake hoses (Continued)
Pumping Apparatus Driver/Operator 12–25 Inability to Reach the Water with a Pumper Problems can be avoided by: –Using public boat launching facilities –Constructing gravel drives –Installing dry hydrants –Clearing brush to drafting points with a high potential for use –Noting appropriate drafting sites in pre- incident plans
Pumping Apparatus Driver/Operator 12–26 Wet or Soft Ground Approaches Soggy approaches may not support the weight of fire department apparatus. Grass and vegetation can obscure holes and soft spots. Settling may occur after a vehicle stops for a period of time. (Continued)
Pumping Apparatus Driver/Operator 12–27 Wet or Soft Ground Approaches Frozen ground that allows the apparatus to be safely driven across at first may later thaw out and cause the apparatus to sink in place. Very marshy land or land with a high sand content may be too soft to support the weight of the apparatus.
Pumping Apparatus Driver/Operator 12–28 Inadequate Depth for Drafting A depth of 2 feet (0.6 m) of water is suggested above and below a barrel-type strainer. Floating strainers may be used if water is not deep enough for barrel-type strainers. These strainers allow safe drafting from water as shallow as 1 foot (0.3 m) deep. (Continued)
Pumping Apparatus Driver/Operator 12–29 Inadequate Depth for Drafting Low-level strainers can draft from portable water tanks and can draw water down to a 1- to 2-inch (25 mm to 50 mm) depth. In small, fast streams with inadequate draft depth, a ladder and salvage cover can be used to dam the stream and raise the water level to permit drafting.
Pumping Apparatus Driver/Operator 12–30 Silt and Debris May clog the strainer, resulting in reduced water intake May cause seizing-up or damage to fire pumps May clog fog stream nozzles (Continued)
Pumping Apparatus Driver/Operator 12–31 Silt and Debris All hard intake lines should have strainers attached when drafting from a natural source. The intake hose should be located and supported so that the strainer does not rest on or near the bottom to avoid getting dirt and debris into the strainer. (Continued)
Pumping Apparatus Driver/Operator 12–32 Silt and Debris Either a single ladder or a roof ladder can be used to keep the strainer off the bottom. (Continued)
Pumping Apparatus Driver/Operator 12–33 Silt and Debris Can be avoided by the installation of a dry hydrant –Allows access to natural sources without the set-up time required for a regular drafting operation –Avoids the wet ground approach problem and can circumvent the problem of silt and debris when installed properly
Pumping Apparatus Driver/Operator 12–34 Aiding Access to Frozen Ponds and Lakes Barrels filled with antifreeze solution are floated on the water’s surface before the water freezes. If the need to draft arises, the top and the bottom of the barrel may be knocked out to provide an access hole for the intake hose and strainer. (Continued)
Pumping Apparatus Driver/Operator 12–35 Aiding Access to Frozen Ponds and Lakes Wooden plugs or plastic garbage cans are stabilized at a location so that they may be driven through the ice if the need to draft arises. It may be necessary to cut a hole through the ice using an axe, chain saw, or power auger. (Continued)
Pumping Apparatus Driver/Operator 12–36 Aiding Access to Frozen Ponds and Lakes CAUTION! Extreme caution should be taken when operating on the ice. Provisions for making an ice rescue should be on scene before firefighters begin working on the ice. All firefighters working in close proximity to bodies of water must wear personal flotation devices (PFDs).
Pumping Apparatus Driver/Operator 12–37 Swift Water The current may make it difficult to keep the strainer submerged below the surface of the water. All firefighters working near the water’s edge must wear a PFD.
Pumping Apparatus Driver/Operator 12–38 Man-Made Water Supply Sources Cisterns Private water storage tanks Ground reservoirs Swimming pools Agricultural irrigation systems
Pumping Apparatus Driver/Operator 12–39 Cisterns Underground water storage receptacles found in areas not serviced by a hydrant system Receive water from wells or rainwater runoff (Continued)
Pumping Apparatus Driver/Operator 12–40 Cisterns Are usually for domestic or agricultural use Some are placed for fire department use as a backup if the water supply system fails Sizes from 10,000 to 100,000 gallons ( L to L) are common (Continued)
Pumping Apparatus Driver/Operator 12–41 Cisterns May be accessed by: –A manhole-type cover that is removed to provide access for intake hose and strainer –Attached dry hydrant arrangement that allows for quick connection by a fire department pumper May be susceptible to freezing if not below the frost line
Pumping Apparatus Driver/Operator 12–42 Private Water Storage Tanks Are commonly found on large residential, industrial, and agricultural properties Range in size from several hundred to many thousands of gallons (liters) May be at ground level or elevated (Continued)
Pumping Apparatus Driver/Operator 12–43 Private Water Storage Tanks May not be reliable, depending on: –Size, –Amount of water inside at time of fire, and –Appropriate connections for fire apparatus
Pumping Apparatus Driver/Operator 12–44 Ground Reservoirs Man-made impoundments that have same characteristics as a pond or small lake Are commonly found on commercial or industrial properties and at municipal water treatment facilities (Continued)
Pumping Apparatus Driver/Operator 12–45 Ground Reservoirs Typically contain many millions of gallons (liters) of water Are typically more accessible than regular ponds or lakes May include dry hydrants to speed their use
Pumping Apparatus Driver/Operator 12–46 Swimming Pools May be difficult to access due to security measures (fences) The pump should be flushed with clear water after drafting from a swimming pool to remove any access chlorine from the pump and piping.
Pumping Apparatus Driver/Operator 12–47 Calculating Swimming Pool Capacities (Square/Rectangular) Customary Capacity in gallons = L x W x D x 7.5 L = Length in feet W = Width in feet D = Average depth in feet 7.5 = Number of gallons per cubic foot (Continued)
Pumping Apparatus Driver/Operator 12–48 Calculating Swimming Pool Capacities (Square/Rectangular) Metric Capacity in liters = L x W x D x L = Length in meters W = Width in meters D = Average depth in meters = Number of liters per cubic meter
Pumping Apparatus Driver/Operator 12–49 Calculating Swimming Pool Capacities (Round) Customary Capacity in gallons = x r 2 x D x 7.5 (Pi) = 3.14 r = Radius or ½ the diameter in feet D = Average depth in feet 7.5= Number of gallons per cubic foot (Continued)
Pumping Apparatus Driver/Operator 12–50 Calculating Swimming Pool Capacities (Round) Metric Capacity in liters = x r 2 x D x (Pi) = 3.14 r = Radius or ½ the diameter in meters D = Average depth in meters 7.5= Number of liters per cubic meter
Pumping Apparatus Driver/Operator 12–51 Agricultural Irrigation Systems May flow in excess of 1,000 gpm (4 000 L/min) Usually transport water one of two ways: –Open canals –Portable pipes
Pumping Apparatus Driver/Operator 12–52 Summary Although many cities and towns have pressurized water systems that supply fire hydrants throughout the jurisdiction, other entities do not have these vital fire fighting facilities. In these cases, fire departments must rely on water tenders or static water sources in fixed locations. (Continued)
Pumping Apparatus Driver/Operator 12–53 Summary Regardless of what static sources may be available, departments who depend on these sources for fire fighting water must know where the sources are located, the approximate capacity of these sources, and what impediments may exist that could prevent the department from using the water contained in them.
Pumping Apparatus Driver/Operator 12–54 Discussion Questions 1.What is the equation for determining maximum lift? 2.What is the equation for determining pressure correction? 3.What is the equation for determining net pump discharge pressure? 4.Name types of natural static water supply sources. (Continued)
Pumping Apparatus Driver/Operator 12–55 Discussion Questions 5.What is the equation for determining the adequacy of a natural stream? 6.Name some common types of man-made static water supply sources. 7.What is the equation for determining the capacity of a square/rectangular swimming pool? 8.What is the equation for determining the capacity of a round swimming pool?