Essentials of Firefighting (4th Edition)
Chapter 11-Water Supply
FF1 Test Review

Why is water the primary extinguishing agent in fires?

  • universal abundance
  • ability to absorb heat

What are the primary advantages of water as an extinguishing agent?

  • can be conveyed long distances
  • easily stored

Who provides the methods for supplying water to populated areas?

  • public and/or private water systems

Who are water departments operated by?

  • city operated, regionally operated, or private water authorities

What is the principal function of water departments?

  • to provide potable water

What should the FD and water department work together on?

  • planning fire protection coverage

What are the 4 fundamental components of a water system?

  • source of water supply
  • means of moving water
  • water processing or treatment facilities
  • water distribution system, including storage

Where are primary water supplies obtained from?

  • surface water (rivers and lakes)
  • groundwater (water wells or water-producing springs)

How is a community's water needs determined?

  • by an engineering estimate of water needed for domestic, industrial, and firefighting use

What are the three methods of moving water?

  • direct pumping systems-(use of 1 or more pumps from the primary source to filtration and treatment process then to distribution system)
  • gravity systems-(primary source located at a higher elevation, several hundred feet higher than the highest elevation of the
  • water distribution system-MOST COMMON-mountain reservoir for the city below)
  • combination systems-(uses a combination of gravity and direct pumping)

What do industrial location sometimes offer?

  • private water systems-elevated tanks, storage tanks, etc

What should storage of water do?

  • be sufficient for domestic, industrial, and firefighting operations
  • to provide adequate supply for repairs to system

What is drafting?

  • process of taking water from a static source into a pump that is above the source's level

What processes are used to treat water?

  • coagulation, sedimentation, filtration, or addition of chemicals, bacteria, or other organisms
  • fluoride or oxygen may also be added to water in the treatment process

What is the FD's main concern regarding treatment facilities?

  • maintenance error, natural disasters, loss of power supply, or fire that disrupts the treatment process

What is the distribution system?

  • the part that receives water from the pumping station and delivers it throughout the area served

What does friction result in?

  • loss of pressure

What is a dead-end hydrant?

  • receives water from only one direction

What is a circulating-feed or looped line?

  • receives water from two or more directions

What is a grid system?

  • a distribution system that provides circulating feed from several mains

What are the components of a grid system?

  • Primary Feeders (large pipes (16-inch) with relatively widespread spacing and convey large quantities of water to smaller mains)
  • Secondary Feeders ( network of intermediate-sized pipes (12-inch) which reinforce the grid within the primary system) - aid in required fire flow at any point
  • Distributors (grid arrangement of smaller mains (8-inch) serving individual fire hydrants and consumers)

How should primary feeders be routed in high-risk areas?

  • 2 or more primary feeders from the source of supply by separate routes

How should secondary feeders be arranged?

  • in loops to give 2 directions of supply to any point (ensures a break in the line will not completely cut off supply)

What is the recommended hydrant main size and connecting main specs?

  • (RESIDENTIAL) 6-inch supply mains with 8-inch cross-connecting mains at intervals not more than 600 feet
  • (INDUSTRIAL) 8-inch supply main with cross connecting mains every 600 feet
  • (PRINCIPAL STREETS AND LONG MAINS) 12-inch mains and not cross-connected

What is the function of a valve?

  • to provide a means of controlling water flow through a distribution system

How often should valves be operated?

  • at least once yearly

Why should valves be located at frequent intervals?

  • so that only small districts are cut off if it is necessary to stop flow at specific points

When should valves be inspected and operated by fire personnel?

  • during hydrant inspections

What is an indicating valve?

  • visually shows whether the gate or valve seat is open, closed, or partially closed
  • fire protection systems are usually of the indicating valve type

What is a post indicator valve (PIV)?

  • indicating valve that consists of a hollow metal post attached to the valve housing
  • valve stem has the words OPEN and SHUT printed on it

What is an outside screw and yoke (OS&Y) valve?

  • has a yoke on the outside with a threaded stem that controls the valve
  • threaded portion is out of the yoke when open
  • threaded portion is in the yoke when closed

Describe a gate valve?

  • usually the non-rising stem type
  • as valve nut is turned, gate rises or lowers
  • marked with number of turns needed to close

Describe a butterfly valve?

  • tight closing and usually have a rubber or rubber composition seat bonded to valve body
  • valve disk rotates 90 degrees from fully-open position to tight-shut position
  • non-indicating butterfly valve requires a valve key
  • provides satisfactory water control after long periods of inactivity

What are some advantages of proper valve installation?

  • normally only have to close 1 or 2 hydrants to provide repairs
  • reduced if not maintained and kept fully open

What is caused by partially open valves?

  • high friction loss

What are water pipes made of?

  • cast iron, ductile iron, asbestos cement, steel, plastic, or concrete

What are some areas and materials that might be used in unstable areas?

  • steel or reinforced concrete
  • in areas with unstable or corrosive soil, beneath railroad tracks, close to heavy machinery, areas prone to earthquakes, and areas of rugged terrain

How is friction loss increased?

  • encrustation of minerals on interior surfaces of pipe
  • sedimentation

Define pressure.

  • velocity of water in a conduit (pipe or hose) of a certain size

How is pressure measured?

  • pounds per square inch (psi) or kilopascal (kPa)

What are the kinds of pressure and their meaning?

  • Static Pressure-stored potential energy available to force water through pipe, fittings, fire hose, and adapters (normal pressure existing on a system before the flow hydrant is opened)
  • Normal Operating Pressure-found in a water distribution system during periods of normal consumption (average daily use during a one-year period)
  • Residual Pressure-part of the total available pressure that is not used to overcome friction or gravity while forcing water through pipe, fittings, fire hose, and adapters
  • Flow Pressure-forward velocity pressure at a discharge opening, either at a hydrant discharge or a nozzle orifice while water is flowing

Describe a dry-barrel hydrant?

  • used in freezing climates
  • usually classified as a compression, gate, or knuckle-joint type that either opens with or against pressure
  • valve located below the frost line
  • barrel is empty when valve is closed
  • drain is open when the hydrant is not flowing
  • if hydrant is not fully open, drain is left partially open

How do you check to see if hydrant is draining?

  • a slight vacuum should be felt at the discharge opening

Describe wet-barrel hydrants.

  • used in areas that DO NOT have freezing weather
  • compression type valve at each outlet
  • may only have one valve in the bonnet that controls all outlets
  • always filled with water
  • all hydrant bonnets, footpieces, and barrels made of cast iron
  • working parts usually made of bronze
  • valve facings may be rubber, leather, or composition materials

Name the hydrant color codes.

  • Class AA - Light Blue - 1,500gpm or greater
  • Class A - Green - 1,000-1,499gpm
  • Class B - Orange - 500-999gpm
  • Class C - Red - less than 500gpm

Who is responsible for the location of fire hydrants?

  • fire chief or fire marshal

How far apart should fire hydrants be spaced in high-value districts?

  • not more than 300 feet

What is a basic rule for hydrant placement?

  • near each intersection
  • intermediate hydrants between intersections that exceed 350-400 feet

What are some other factors that dictate hydrant location?

  • types of construction
  • types of occupancies
  • congestion
  • sizes of water mains
  • required fire flows
  • pumping capacities

Who is responsible for repair and maintenance of fire hydrants?

  • the water department

Who performs water supply testing and hydrant inspections?

  • the fire department

What are some potential problems to look for when checking hydrants?

  • obstructions such as sign posts, utility poles, fences
  • outlets facing proper direction for pumper-to-hydrant connection
  • sufficient clearance between ground and outlets
  • hydrant damage due to vehicle accidents
  • rusting or corrosion
  • hydrant caps stuck with paint
  • operating stem easily turned
  • obstructions such as bottles, cans, rocks restricting water flow

What are some natural sources of water?

  • ocean, lakes, ponds, and rivers
  • farm stock tanks, swimming pools

What is the most important operational consideration when drafting?

  • silt and debris that clogs strainers, damages pumps, and clogs fog-stream nozzles

What is a good guideline for hard suction placement?

  • 24 inches on all sides of the strainer

What are the depth requirements of special drafting floating strainers?

  • 1-2 inches

What is water shuttling?

  • hauling of water from a supply source to portable tanks from which water may be drawn to fight a fire

When is water shuttling recommended?

  • on distances greater than 1/2 mile than the department's capability of laying supply lines

What are the keys to efficient water shuttling?

  • fast dump and fill times

Where should water supply officers be placed during water shuttling?

  • at dump site and fill site

Where should tanker/tender drivers remain while shuttling?

  • in their vehicles

What are the 3 key components of water shuttle?

  • attack apparatus at the fire (dump site)
  • fill apparatus at the fill site
  • mobile water supply apparatus to haul water between dump and fill sites

Where is the dump site usually located?

  • near the actual fire or incident

What does the dump site consist of?

  • 1 or more portable tanks into which hauling apparatus dump water before returning to fill site

What device permits the use of portable reservoirs?

  • low-level intake devices

What are the capacities of portable tanks?

  • 1,000 gallons and up

What does a jet siphon do?

  • maintains the water level in the pumper portable tank while the dump tank is utilized by tanker/tenders dumping water

What size line does a jet siphon use?

  • 1 1/2 inch line

What is the most common type of portable reservoir?

  • square metal frame and synthetic or canvas duck liner
  • also available, round, synthetic tanks with floating collar

What should be spread on the ground before using a portable tank?

  • a heavy tarp

What NFPA standard covers water supply?

  • NFPA 1231

What does NFPA 1901 state regarding dump and fill rates?

  • capable of at least 1,000 gpm

What are the 4 basic methods that tanker/tenders unload water?

  • gravity dumping (through 10-12 inch dump valves)
  • jet dumps (by creating a venturi effect)
  • apparatus mounted pumps that offload water
  • combinations of methods

What are the 2 important factors in establishing relay operations?

  • water supply must be capable of maintaining desired volume of water
  • relay must be established quickly to be worthwhile

How is the number of pumpers needed to relay determined?

  • volume of water needed
  • distance between water source and fire
  • hose size available
  • amount of hose available
  • pumper capacities

Where should the pumper with the greatest capacity be placed during relay?

  • at the water source