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Pumping Apparatus Driver/Operator — Lesson 12

Pumping Apparatus Driver/Operator — Lesson 12. Pumping Apparatus Driver/Operator Handbook, 2 nd Edition Chapter 12 — Static Water Supply Sources. Learning Objectives. 1. Match to their definitions terms associated with static water sources.

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Pumping Apparatus Driver/Operator — Lesson 12

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  1. Pumping Apparatus Driver/Operator — Lesson 12 Pumping Apparatus Driver/Operator Handbook, 2nd Edition Chapter 12 — Static Water Supply Sources

  2. 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

  3. 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

  4. 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

  5. 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

  6. Learning Objectives 14. State the equations for determining the capacity of various kinds of pools. 15. Calculate swimming pool capacities. Pumping Apparatus Driver/Operator

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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. 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

  13. 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

  14. Calculating Maximum Lift • Metric L = (0.013 56)(Hg) L = Height of lift in meters 0.013 56 = A constant Hg = mm of mercury Pumping Apparatus Driver/Operator

  15. 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

  16. 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

  17. 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

  18. Determining Net Pump Discharge Pressure at Draft NPDPDraft = PDP + Intake pressure correction NPDPDraft = Net pump discharge pressure at draft PDP = Pump discharge pressure in psi or kPa Pumping Apparatus Driver/Operator

  19. Natural Static Water Supply Sources • Lakes • Ponds • Rivers • Oceans Pumping Apparatus Driver/Operator

  20. 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

  21. Calculating Natural Stream Adequacy • Customary Q = A x V x 7.5 Q = Flow in gpm A = Area in ft2 (width x depth)V = Velocity in ft/min 7.5 = A constant (the number of gallons per ft3) (Continued) Pumping Apparatus Driver/Operator

  22. Calculating Natural Stream Adequacy • Metric Q = A x V x 1 000 Q = Flow in L/min A = Area in m2 (width x depth)V = Velocity in m/min 1 000= A constant (the number of liters per m3) (Continued) Pumping Apparatus Driver/Operator

  23. 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

  24. 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

  25. 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

  26. 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

  27. 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

  28. 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

  29. 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

  30. 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

  31. 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

  32. 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

  33. 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

  34. 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

  35. 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

  36. 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

  37. 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

  38. 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

  39. Man-Made Water Supply Sources • Cisterns • Private water storage tanks • Ground reservoirs • Swimming pools • Agricultural irrigation systems Pumping Apparatus Driver/Operator

  40. 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

  41. 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 (40 000 L to 400 000 L) are common (Continued) Pumping Apparatus Driver/Operator

  42. 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

  43. 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

  44. 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

  45. 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

  46. 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

  47. 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

  48. 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

  49. Calculating Swimming Pool Capacities (Square/Rectangular) • Metric Capacity in liters = L x W x D x 1 000 L = Length in meters W = Width in meters D = Average depth in meters 1 000 = Number of liters per cubic meter Pumping Apparatus Driver/Operator

  50. Calculating Swimming Pool Capacities (Round) • Customary Capacity in gallons =  x r2 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

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