Chapter 15 Water Supply Flashcards
What two sources to Fire fighters obtain water from?
- Municipal water systems- Furnish water under pressure through fire hydrants.
- Static water sources- such as lakes and streams
Dry Hydrants
also called drafting hydrants, provide quick and reliable access to static water sources.
Standard on Water Supplies for Suburban and Rural Fire Fighting
NFPA 1142
Mobile water supply apparatus
often called tankers or water tenders. Engines carry 500 gallons Tankers carry 1000-3500 some 5000 gallons
Portable Tanks
Carried on fire apparatus can be quickly set up at a fire scene. 600 to 5000 gallons
Dump Valve
- tankers can off load as much as 3000 gallons per minute.
2. the faster it off loads the faster it can return to the fill site for another load.
Tanker Shuttle
used when a large volume of water is needed for an extended period at a fire. efficiently delivers several hundred gallons of water per minute without
Where do Municipal water come from?
water is drawn from wells, rivers, streams, lakes or human made storage facilities called RESERVOIR.
Water Mains
the distribution system delivers water from the treatment facility to the end users and fire hydrants through a complex network of underground pipes.
Water Hydrant PSI
minimum 20psi to 80psi
Gravity Fed System
the water source, treatment plant and storage facilities are located on high ground while the end users live in lower lying areas.
Elevated Water Storage Towers
facilities maintain the desired water pressure in the distribution system, ensuring that water can be delivered under pressure even if the pumps are not operating.
Primary Feeders
Large mains carry large quantities of water to a section the town/city
Secondary Feeders
Distribute water to a smaller area
Distributors
smallest pipes carry water to the users and hydrants along individual streets
Shut off Valves
Located at the connection points where the underground mains meet the distributor pipes. valves control the flow of water to customers or individual fire hydrants.
Types of Hydrants
- Wet Barrel Hydrants
2. Dry Barrel Hydrants
Private water systems
Supplied by the municipal water system or from a separate source.
Wet-barrel hydrants
Used in locations where temps. do not drop below freezing. they always have water in the in the barrel and do not have to be drained.
Dry-barrel hydrants
used in climates where temperatures can be expected to fall below freezing. Valve controls the flow of water into the barrel.
Fire Hydrant location
500 ft. in residential areas and every 300 ft. in high value commercial and industrial areas. At intersection and middle block, and every 100 ft. FD connection for large buildings
Red Hydrant Specs Class C
less than 500 gpm
Orange Hydrant Class B
500-999 gpm
Green Hydrant Class A
1000-1499 gpm
Light Blue Class AA
1500 gpm
Static Pressure
the pressure in a system when the water is not moving, Static pressure is potential energy.
Elevation Pressure
Static pressure is generally created by elevation pressure.
Normal Operating Pressure
to the amount of pressure in a water distribution system during a period of normal consumption. May change depending on time of day.
Residual Pressure
the amount of pressure that remains in the system when water is flowing.
Flow Pressure
Measures the quantity of water flowing through an opening during a hydrant test.
Pilot Gauge
is used to measure flow pressure in psi and to calculate the flow in gallons per minute.
Dry Hydrant not dry barrel
provide quick and reliable access to static water sources. Its a pipe with a strainer (24inches) around strainer
Parts of a dry barrel hydrant (8)
- Barrel
- bonnet
- stem nut
- main valve
- Drain holes
- operating stem
- 2- 2.5 inch connections
- 1- 4.5 inch steamer port
Water Hammer
recoil or shockwave cause by opening or closing nozzle quickly
Municipal
- water distribution
- water source
- water facility
