Pumping Apparatus DriverOperator Lesson 6

1
Pumping Apparatus Driver/Operator Lesson 6

• Pumping Apparatus Driver/Operator Handbook, 2nd
  Edition
• Chapter 6 What Is Water and Where Does It Come
  From?

2
Learning Objectives

• 1. Select facts about the characteristics of
  water.
• 2. List the ways in which water has the ability
  to extinguish fire.
• 3. Answer questions about specific heat.
• 4. Select facts about latent heat of vaporization.

3
Learning Objectives

• 5. Calculate latent heat of vaporization.
• 6. Answer questions about the surface area of
  water.
• 7. Explain the ways in which water smothers fire.
  
• 8. Select facts about specific gravity.

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Learning Objectives

• 9. List advantages of water as an extinguishing
  agent.
• 10. List disadvantages of water as an
  extinguishing agent.
• 11.Distinguish between pressure and force.
• 12.Explain how force is determined.

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Learning Objectives

• 13.State the principles of fluid pressure.
• 14.Match to their definitions terms associated
  with pressure.
• 15.Explain how to measure atmospheric pressure.
• 16.Calculate head pressure.

6
Learning Objectives

• 17.List causes of friction loss in fire hose.
• 18.List causes of friction loss in piping
  systems.
• 19.List the principles of friction loss.
• 20.Answer questions about other factors affecting
  friction loss.

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Learning Objectives

• 21.List ways to reduce friction loss.
• 22.Select facts about water hammer.
• 23.Name the four primary components of a
  municipal water system.
• 24.Answer questions about the primary components
  of a municipal water system.

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Learning Objectives

• 25.Select facts about water main valves.
• 26.Answer questions about water pipes.
• 27.Match to their definitions water system
  consumption rates.
• 28.Select facts about private water supply
  systems.

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Learning Objectives

• 29.List the purposes of a private water supply
  system.
• 30.List the advantages to have separate piping
  arrangements in a private water supply system.

10
Characteristics of Water

• Water is a compound of hydrogen and oxygen formed
  when two hydrogen atoms (H2) combine with one
  oxygen atom (O).
• Between 32ºF and 212ºF (0ºC and 100ºC), water
  exists in a liquid state.

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Characteristics of Water

• Below 32º F (0ºC) (the freezing point of water),
  water converts to a solid state called ice.
• Above 212ºF (100ºC) (the boiling point of water),
  water converts into a gas called water vapor or
  steam it cannot be seen.

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Characteristics of Water
13
Characteristics of Water

• Water is considered to be incompressible, and its
  weight varies at different temperatures.
• Note Water is measured in pounds per cubic foot
  (kg/L)

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Characteristics of Water

• Water is heaviest close to its freezing point,
  weighing approximately 62.4 lb/ft3 (1 kg/L)
• Water is lightest close to its boiling point,
  weighing approximately 60 lb/ft3 (0.96 kg/L)
• For fire protection purposes, ordinary fresh
  water is generally considered to weigh 62.5
  lb/ft3 or 8.33 lb/gal (1 kg/L)

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Ways in WhichWater Extinguishes Fire

• Cooling
• By absorbing heat from the fire
• Smothering
• Water can be used to smother fires in combustible
  liquids whose specific gravity is higher than 1.
• Smothering also occurs to some extent when water
  converts to steam in a confined space.

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Specific Heat

• The heat-absorbing capacity of a substance
• Amounts of heat transfer are measured in British
  thermal units (Btu) or joules (J)
• A Btu is the amount of heat required to raise the
  temperature of 1 pound of water 1ºF.
• The joule has taken the place of the calorie (1
  calorie 4.19 joules).

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Specific Heat

• Is the ratio between the amount of heat needed to
  raise the temperature of a specified quantity of
  a material and the amount of heat needed to raise
  the temperature of an identical quantity of water
  by the same number of degrees.
• Of different substances varies. Refer to Table
  6.1 on p. 136 of the manual.

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Latent Heat of Vaporization

• Is the quantity of heat absorbed by a substance
  when changing from liquid to vapor.
• The temperature at which a liquid absorbs enough
  heat to change to vapor is known as its boiling
  point. At sea level, water begins to boil or
  vaporize at 212ºF (100ºC).

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Latent Heat of Vaporization

• Vaporization does not completely occur the
  instant water reaches the boiling point.
• Each pound of water requires approximately 970
  Btu (1 023 kJ) of additional heat to convert
  completely to steam.

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Latent Heat of Vaporization
21
Latent Heat of Vaporization

• The latent heat of vaporization is significant in
  fire fighting because the temperature of the
  water is not increased beyond 212ºF during the
  absorption of the 970 Btu for every pound of
  water.

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Surface Area of Water

• The speed with which water absorbs heat increases
  in proportion to the water surface exposed to the
  heat.

23
Surface Area of Water

• Water expands when converted to steam. At 212ºF
  (100ºC), water expands approximately 1,700 times
  its original volume.

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Steam Expansion
25
Surface Area of Water

• Steam expansion is rapid inside a burning
  building. The use of a fog stream in a fire
  attack requires that adequate ventilation be
  provided ahead of the hose line.

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Expansion Data
27
Ways in Which Water Smothers Fire

• By floating on liquids
• Water floats on liquids that are heavier than
  water.
• If the material is water soluble, the smothering
  action is not likely to be effective.
• By forming an emulsion
• Water smothers fire by forming an emulsion over
  the surface of certain combustible liquids.

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Ways in WhichWater Smothers Fire

• By forming an emulsion
• When a spray of water agitates the surface, the
  agitation causes the water to be suspended in
  emulsion bubbles on the surface the emulsion
  bubbles smother the fire.
• Emulsion bubbles can only form when the
  combustible liquid has sufficient viscosity the
  tendency of a liquid to possess internal
  resistance to flow.

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Specific Gravity

• The density of liquids in relation to water
• Water is given a value of 1. Liquids with a
  specific gravity less than 1 are lighter than
  water and float on water.
• Those with a specific gravity greater than 1 are
  heavier than water and sink to the bottom. Most
  flammable liquids have a specific gravity of less
  than 1.

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Advantages of Water asan Extinguishing Agent

• Water has a greater heat-absorbing capacity than
  other common extinguishing agents.
• A relatively large amount of heat is required to
  change water to steam. This means that more heat
  is absorbed from the fire.

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Advantages of Water asan Extinguishing Agent

• The greater the surface area of water exposed,
  the more rapidly heat is absorbed. The exposed
  surface are of water can be expanded by using fog
  streams or deflecting solid streams off objects.

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Advantages of Water asan Extinguishing Agent

• Water converted into steam occupies 1,700 times
  its original volume.
• Water is plentiful, relatively inexpensive, and
  readily available in most jurisdictions.

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Disadvantages of Water asan Extinguishing Agent

• Water has a high surface tension and does not
  readily soak into dense materials. However, when
  wetting agents are mixed with water, the waters
  surface tension is reduced and its penetrating
  ability is increased.
• Water may be reactive with certain fuels such as
  combustible metals.

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Disadvantages of Water asan Extinguishing Agent

• Water has low levels of opacity and reflectivity
  that allow radiant heat to easily pass through
  it.
• Water readily conducts electricity, which can be
  hazardous to firefighters working around
  energized electrical equipment.

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Disadvantages of Water asan Extinguishing Agent

• Water freezes at 32ºF (0ºC), which is a problem
  in jurisdictions that frequently experience
  freezing conditions.
• Water freezing poses a hazard to firefighters by
  coating equipment, roofs, ladders, and other
  surfaces.
• In addition, ice forming in and on equipment may
  cause it to malfunction.

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Pressure vs. Force

• Pressure
• Force per unit area
• May be expressed in pounds per square foot (psf),
  pounds per square inch (psi), or kilopascals
  (kPa)
• Force
• A simple measure of weight
• Is usually expressed in pounds or kilograms

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Determining Force(Customary System)

• The weight of 1 cubic foot of water is
  approximately 62.5 pounds.
• Because 1 square foot contains 144 square inches,
  the weight of water in a 1-square-inch column of
  water 1 foot high equals 62.5 pounds divided by
  144 square inches 62.5 / 144 0.434 pounds

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Determining Force(Customary System)
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Determining Force (Customary System)

• A 1-square-inch column of water 1 foot high
  exerts a pressure at its base of 0.434 psi.
• The height required for a 1-square-inch column of
  water to produce 1 psi at its base equals 1 foot
  divided by 0.434 psi/ft.
• Therefore, 2.304 feet of water column exerts a
  pressure of 1 psi at its base.

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Determining Force(Metric System)

• A cube that is 0.1 m x 0.1 m x 0.1 m (a cubic
  decimeter) holds 1 liter of water.
• The weight of 1 liter of water is 1 kilogram.
• The cube of water holds 1 000 liters of water and
  weighs 1 000 kg.

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Determining Force(Metric System)

• Because the cubic meter of water is comprised of
  100 columns of water, each 10 decimeters tall,
  each column exerts 10 kPa at its base.

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Determining Force(Metric System)
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Principles of Fluid Pressure
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Principles of Fluid Pressure

• Second Principle Fluid pressure at a point in a
  fluid at rest is the same intensity in all
  directions.

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Principles of Fluid Pressure

• Third Principle Pressure applied to a confined
  fluid from without is transmitted equally in all
  directions.

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Principles of Fluid Pressure

• Fourth Principle The pressure of a liquid in an
  open vessel is proportional to its depth.

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Principles of Fluid Pressure

• Fifth Principle The pressure of a liquid in an
  open vessel is proportional to the density of the
  liquid

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Principles of Fluid Pressure

• Sixth Principle The pressure of a liquid on the
  bottom of a vessel is independent of the shape of
  the vessel.

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Terms Associated with Pressure

• Atmospheric pressure Pressure exerted by the
  atmosphere at sea level (14.7 psi 101 kPa)
• psig Pounds per square inch gauge actual
  atmospheric pressure gauge reading
• psia Pounds per square inch absolute the psi
  above a perfect vacuum, absolute zero

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Terms Associated with Pressure

• Vacuum Any pressure less than atmospheric
  pressure
• Perfect vacuum Absolute zero pressure
• Negative pressure Gauge readings of less than 0
  psi or kPa
• Note The term negative pressure is technically a
  misnomer.

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Terms Associated with Pressure

• Head The height of a water supply above the
  discharge orifice
• Head pressure The result of dividing the number
  of feet that the water supply is above the
  discharge orifice by 2.304
• Static pressure Stored potential energy
  available to force water through pipe, fittings,
  fire hose, and adapters

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Terms Associated with Pressure

• Static At rest or without motion
• Normal operating pressure That pressure found
  in a water distribution system during normal
  consumption demands
• Residual pressure That part of the total
  available pressure not used to overcome friction
  loss or gravity while forcing water through pipe,
  fittings, fire hose, and adapters

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Terms Associated with Pressure

• Residual A remainder or that which is left
• Flow pressure (velocity pressure) That forward
  velocity pressure at a discharge opening while
  water is flowing
• Elevation The center line of the pump or the
  bottom of a static water supply source above or
  below ground level

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Terms Associated with Pressure

• Altitude The position of an object above or
  below sea level
• Pressure loss When a nozzle is above the pump
• Pressure gain When the nozzle is below the pump

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Terms Associated with Pressure

• Elevation pressure Another term for both
  pressure loss and pressure gain
• Friction loss That part of the total pressure
  lost while forcing water through pipe, fittings,
  fire hose, and adapters

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Measuring Atmospheric Pressure

• Compare the weight of the atmosphere with the
  weight of a column of mercury.
• Example A pressure of 1 psi (6.9 kPa) makes the
  column of mercury about 2.04 inches (52 mm) tall.
  At sea level, the column of mercury is 2.04 x
  14.7, or 29.9 inches (759 mm) tall.

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Measuring Atmospheric Pressure
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Causes of Friction Loss in Fire Hose

• Movement of water molecules against each other
• Linings in fire hose
• Couplings
• Sharp bends
• Change in hose size or orifice by adapters
• Improper gasket size

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Causes of Friction Loss in Piping System

• Movement of water molecules against each other
• Inside surface of the piping
• The rougher the inner surface of the pipe, the
  more friction loss
• Pipe fittings
• Bends
• Control valves

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Principles of Friction Loss

• First Principle If all other conditions are the
  same, friction loss varies directly with the
  length of the hose or pipe.

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Principles of Friction Loss
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Principles of Friction Loss

• Second Principle When hoses are the same size,
  friction loss varies approximately with the
  square of the increase in the velocity of the
  flow.

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Principles of Friction Loss
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Principles of Friction Loss

• Third Principle For the same discharge,
  friction loss varies inversely as the fifth power
  of the diameter of the hose
• Fourth Principle For a given flow velocity,
  friction loss is approximately the same,
  regardless of the pressure on the water.

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Other FactorsAffecting Friction Loss

• Water is practically incompressible. The same
  volume of water supplied into a fire hose under
  pressure at one end will be discharged at the
  other end.
• Friction loss in a system increases as the length
  of hose or piping increases. Flow pressure is
  greatest near the supply source and lowest at the
  farthest point in the system.

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Other FactorsAffecting Friction Loss

• When the valve on the nozzle end of a hose is
  opened, water flows moderately at a low pressure.
  
• If the opening is made directly at the hydrant,
  the flow will be much greater at a higher
  pressure.
• Decreasing the amount of water flowing through a
  hose reduces the speed of the water in the hose
  less friction loss occurs.

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Other FactorsAffecting Friction Loss

• If velocity is increased beyond practical limits,
  the friction becomes so great that resistance
  agitates the entire stream, creating critical
  velocity.
• Beyond this point, it becomes necessary to
  parallel or siamese hose lines to increase the
  flow and reduce friction.

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Ways to Reduce Friction Loss

• Minimize sharp bends or kinks in the hose by
  using proper hose handling techniques.
• Reduce the length of the hose or increase its
  diameter.

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Water Hammer

• Suddenly stopping water moving through a hose or
  pipe results in an energy surge being transmitted
  in the opposite direction, often at many times
  the original pressure.
• This surge is referred to as water hammer.
• Water hammer can damage the pump, appliances,
  hose, or the municipal water system itself.

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Water Hammer
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Water Hammer

• Always open and close nozzle controls, hydrants,
  valves, and hose clamps slowly to prevent water
  hammer.
• Apparatus inlets and remote outlets should be
  equipped with pressure relief devices to prevent
  damage to equipment.
• High-volume systems should be protected with dump
  valves.

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Primary Components ofMunicipal Water Systems

• Source of water supply
• Means of moving water
• Water processing or treatment facilities
• Water distribution system, including storage

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Source of Water Supply

• The primary water supply can be obtained from
  either surface water or groundwater.
• Although most water systems are supplied from
  only one source, there are instances where both
  sources are used.

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Means of Moving Water

• Direct pumping system
• Uses one or more pumps to take water from the
  primary source and discharge it through the
  filtration and treatment processes
• Includes a series of pumps that then forces the
  water into the distribution system

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Direct Pumping System
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Gravity System
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Means of Moving Water

• Gravity system
• Uses a primary water source located at a higher
  elevation than the distribution system
• Works best when the primary water source is
  located at least several hundred feet (meters)
  higher than the highest point in the water
  distribution system

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Means of Moving Water

• Combination system
• Is a combination of a direct pumping system and a
  gravity system
• Includes elevated storage tanks to supply the
  gravity flow

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Combination System
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Water Processing or Treatment Facilities

• The treatment of water for the water supply
  system is a vital process.
• Water is treated to remove contaminants that may
  be detrimental to the health of those who use or
  drink it.

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Water Processing orTreatment Facilities

• The treatment of water for the water supply
  system is a vital process.
• Water is treated to remove contaminants that may
  be detrimental to the health of those who use or
  drink it.

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Water Processing orTreatment Facilities

• The main concern regarding treatment facilities
  is that a maintenance error, natural disaster,
  loss of power supply, or fire could disable the
  pumping station's or severely hamper the
  purification process.
• Any of these situations would drastically reduce
  the volume and pressure of water available for
  fire fighting operations.

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Water Distribution System,Including Storage

• The distribution system is the part that receives
  the water from the pumping station and delivers
  it throughout the area served.
• The ability of a water system to deliver an
  adequate quantity of water relies upon the
  carrying capacity of the systems network of
  pipes.

84
Water Distribution System, Including Storage

• When water flows through pipes, its movement
  causes friction that results in a reduction of
  pressure.
• There is much less pressure loss in a water
  distribution system when fire hydrants are
  supplied from two or more directions.

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Water Distribution System, Including Storage

• A fire hydrant that receives water from only one
  direction is known as a dead-end hydrant.
• A fire hydrant that receives water from two or
  more directions is called a circulating feed or a
  looped line.

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Water Distribution System, Including Storage
87
Water Distribution System, Including Storage

• A distribution system that provides circulating
  feed from several mains constitutes a grid
  system, consisting of the following components
• Primary feeders
• Secondary feeders
• Distributors

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Water Supply Grid System
89
Water Distribution System, Including Storage

• Primary feeders Large pipes with widespread
  spacing that convey large amounts of water to
  various points of the system for local
  distribution to smaller mains
• Secondary feeders Network of intermediate-sized
  pipes that reinforce the grid within the various
  loops of the primary feeder system and aid the
  concentration of the required fire flow

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Water Distribution System, Including Storage

• Distributors Grid arrangement of smaller mains
  serving individual fire hydrants and blocks of
  consumers

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Water Distribution System, Including Storage

• To ensure sufficient water, two or more primary
  feeders should run from the source of supply to
  the high-risk and industrial districts of the
  community by separate routes.

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Water Distribution System, Including Storage

• In residential areas, the recommended size for
  fire hydrant supply mains is at least 6 inches
  (150 mm) in diameter.
• These should be closely gridded by 8-inch (200
  mm) cross-connecting mains at intervals of not
  more than 600 feet (180 m)

93
Water Distribution System, Including Storage

• In the business and industrial districts, the
  minimum recommended size is an 8-inch (200 mm)
  main with cross-connecting mains every 600 feet
  (180 m)

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Water Distribution System, Including Storage

• Twelve-inch (300 mm) mains may be used on
  principal streets and in long mains not
  cross-connected at frequent intervals.
• Water mains as large as 48 inches (1.2 m) may be
  found in major cities.

95
Water Main Valves

• The function of a valve in a water distribution
  system is to provide a means for controlling the
  flow of water through the distribution piping.
• Valves should be located at frequent intervals so
  that only small districts are cut off if it is
  necessary to stop the flow at specified points.

96
Water Main Valves

• Valves should be operated at least once a year to
  keep them in good condition.
• One of the most important factors in a water
  supply system is the water departments ability
  to promptly operate the valves during an
  emergency or breakdown of equipment.

97
Water Main Valves

• Indicating valves
• Shows whether the gate or valve seat is open,
  closed, or partially closed
• Are the most commonly used valves in private fire
  protection systems

98
Water Main Valves

• Indicating valves
• Post indicator valve (PIV) A hollow metal post
  attached to the valve housing. The valve stem
  inside has the words OPEN and SHUT printed so
  that the valve position is shown.

99
Water Main Valves

• Indicating valves
• Outside screw and yoke (OSY) Has a yoke on
  outside with threaded stem that controls gates
  opening or closing.
• The threaded part of the stem is out of the yoke
  when the valve is open and inside the yoke when
  the valve is closed.

100
Water Main Valves

• Nonindicating valves
• Are buried or installed in manholes
• Are the most common types of valves used on most
  public water distribution systems

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Water Main Valves

• Control valves
• Gate valves
• Butterfly valves

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Water Main Valves

• If valves are installed according to established
  standards, it normally will be necessary to close
  off only one or perhaps two fire hydrants from
  service while a single break is being repaired.
• This cannot occur unless valves are properly
  maintained and kept fully open.

103
Water Main Valves

• High friction loss is caused by valves that are
  only partially open.
• A fire department will experience difficulty in
  obtaining water in areas where there are closed
  or partially closed valves in the distribution
  system.

104
Water Main Valves

• High friction loss is caused by valves that are
  only partially open.
• A fire department will experience difficulty in
  obtaining water in areas where there are closed
  or partially closed valves in the distribution
  system.

105
Water Pipes

• Water pipe that is used underground is generally
  made of cast iron, ductile iron, asbestos cement,
  plastic, or concrete.
• The internal surface of the pipe, regardless of
  the material from which it is made, offers
  resistance to water flow.
• Friction loss is increased by encrustation of
  minerals on the interior surfaces of the pipe.

106
Water System Capacity

• Average daily consumption (ADC) The average of
  the total amount of water used in a water
  distribution system over the period of one year
• Maximum daily consumption (MDC) The maximum
  total amount of water that was used during any
  24-hour interval within a 3-year period

107
Water System Capacity

• Peak hourly consumption (PHC) The maximum
  amount of water used in any1-hour interval over
  the course of a day

108
Private Water Supply Systems

• Private water supply systems are most commonly
  found on large commercial, industrial, or
  institutional properties.
• Private water supply systems may service one
  large building or a series of buildings on the
  complex.

109
Private Water Supply Systems

• Purposes
• To provide water strictly for fire protection
  purposes
• To provide water for sanitary and fire protection
  purposes
• To provide for fire protection and manufacturing
  processes

110
Private Water Supply Systems

• The design of private water supply systems is
  typically similar to that of municipal systems.
• Most private water supply systems separate piping
  for fire protection and domestic/ industrial
  services.

111
Private Water Supply Systems

• Advantages
• The property owner has control over the water
  supply source.
• Either of the systems are unaffected by service
  interruptions to the other system.

112
Summary

• All pumping apparatus driver/operators should
• Understand the properties of water as a fire
  extinguishing agent
• Know the factors that influence its delivery
  during a pumping operation
• Be thoroughly familiar with the operation of the
  apparatus to which they are assigned

113
Summary

• Fire department personnel must also be familiar
  with the design and reliability of both public
  and private water supply systems in their
  jurisdiction.

114
Summary

• Large, well-maintained systems may provide a
  reliable source of water for fire protection
  purposes.
• Small capacity, poorly maintained, or otherwise
  unreliable private water supply systems should
  not be relied upon to provide all the water
  necessary for adequate fire fighting operations.

115
Discussion Questions

• 1. How does water have the ability to extinguish
  fire?
• 2. What is specific heat?
• 3. What is the latent heat of vaporization?
• 4. How does water smother fire?
• 5. What is specific gravity?

116
Discussion Questions

• 6. What are the advantages of water as an
  extinguishing agent?
• 7. What are the disadvantages of water as an
  extinguishing agent?
• 8. What is pressure?
• 9. What is force?

117
Discussion Questions

• 10. How is force determined?
• 11. What are the principles of fluid pressure?
• 12. How do you measure atmospheric pressure?
• 13. What are some causes of friction loss in fire
  hose?

118
Discussion Questions

• 14. What are some causes of friction loss in
  piping systems?
• 15. What are the principles of friction loss?
• 16. Name ways to reduce friction loss.
• 17. What is water hammer?
• 18. Name the four primary components of a
  municipal water system.
• Email answers to axe457_at_yahoo.com

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THE END