Transcript CVFD Training – Water Supply

CVFD Training – Water Supply
SFFMA Training Objectives:
12-01.01 – 12-01.05
Hydrants
• Usually made of cast iron with bronze working
parts
• Must be opened and closed slowly to prevent
damage
Firefighter I
12–2
Dry-Barrel Hydrants
• Installed in areas where
prolonged periods of
subfreezing weather are
common
• Have main valve located below
frost line that prevents water
from entering hydrant barrel
(Continued)
Firefighter I
12–3
Dry-Barrel Hydrants
• Operation
• Must be completely open or
closed to prevent leaking
• When shutting down, verify
that water left in hydrant
barrel is draining out
(Continued)
Firefighter I
12–4
Dry-Barrel Hydrants
• In some areas, hydrants must
be pumped out after each
use to prevent water
contamination
• If water is bubbling out of
ground, broken component in
barrel is allowing water to get
past drain opening
Firefighter I
12–5
Wet-Barrel Hydrants
• Installed in warmer climates
where prolonged periods of
subfreezing weather
uncommon
• Horizontal compression-type
valve at each outlet
• Always filled with water
Firefighter I
12–6
Fire Hydrant Marking
• Rate of flow from individual hydrants varies
for several reasons
• NFPA® has developed system of marking
hydrants
• Local color-coding may differ from NFPA®
Firefighter I
12–7
DISCUSSION QUESTION
What types of fire hydrant marking systems
are used in your area?
Firefighter I
12–8
Fire Hydrant Locations
• Decisions usually made by water
department personnel based on
recommendations from fire department
• Should not be spaced more than 300 feet
(100 m) apart in high-value districts
(Continued)
Firefighter I
12–9
Fire Hydrant Locations
• Locate hydrant at every other intersection
• Intermediate hydrants may be required where
distances between intersections exceed 350 to
400 feet (105 to 120 m)
• Other factors affect location/spacing
Firefighter I
12–10
Hydrant Testing and Inspections
• Responsibility of fire
department personnel
• Firefighters should look for
wide array of items
Firefighter I
12–11
Fire Hydrant Testing Process
Many departments no longer responsible for testing
Most basic test normally conducted is flow test
Firefighter I
12–12
Flow Test Steps
•
•
•
•
•
Select hydrant
Remove all outlet caps
Inspect outlet threads
Lubricate all outlet threads
Replace all caps except one 2½-inch (65
mm) cap
(Continued)
Firefighter I
12–13
Flow Test Steps
• Connect cap-type pressure gauge to outlet on
second hydrant nearby
• Turn second hydrant on, record static pressure
• Turn test hydrant on fully, allow water to flow
briefly
(Continued)
Firefighter I
12–14
Flow Test Steps
• Use pitot tube,
gauge to measure
flow rate
• Record pitot gauge
reading
(Continued)
Firefighter I
12–15
Flow Test Steps
• Take/record residual pressure reading from
gauge connected to second hydrant before
shutting test hydrant off
• Turn off second hydrant, remove gauge,
replace cap
• Turn off test hydrant
(Continued)
Firefighter I
12–16
Flow Test Steps
• Test for vacuum created by operating drain
valve (dry barrel)
• Replace cap on outlet
• Repeat procedure with each hydrant
Firefighter I
12–17
DISCUSSION QUESTION
What types of situations or areas would
require an alternative source of water?
Firefighter I
12–18
Alternative Water Supply Sources
•
•
•
•
•
•
•
Lakes
Ponds
Rivers
Ocean
Swimming pools
Farm stock tanks
Underground cisterns
Firefighter I
12–19
DISCUSSION QUESTION
Can you think of any other types of alternative
water supplies?
Firefighter I
12–20
Drafting From Alternative Water
Supplies
• Process of drawing water from static source to
pumper
• Can use almost any static source of water if
sufficient in quantity, not contaminated
(Continued)
Firefighter I
12–21
Drafting From Alternative Water
Supplies
• Depth of water from which to draft
Firefighter I
12–22
Dry Hydrants
• Installed at static water sources to increase
water supply available
• Usually constructed of steel or PVC pipe with
strainers at water source, steamer ports to
connect to pumper
• Designed to supply at least 1,000 gpm (4 000
L/min)
(Continued)
Firefighter I
12–23
Water Shuttles
• Involve hauling water from supply source to
portable tanks from which water may be
drawn to fight fire
• Recommended for distances greater than ½
mile (0.8 km) or greater than the fire
department’s capability of laying supply
hoselines
(Continued)
Firefighter I
12–24
Water Shuttles
• Critical elements
– Fast-fill, fast-dump capabilities
– Water supply officers at fill/dump sites
– Traffic control
– Hydrant operations
– Hookups
– Tank venting
Firefighter I
12–25
Water Shuttles
• Key components
• Dump site
• Portable tanks
(Continued)
Firefighter I
12–26
Water Shuttles
• Ways in which water
tenders unload
– Gravity dumping
– Jet dumps that increase flow
rate
– Apparatus-mounted pumps
– Combination of these
methods
Firefighter I
(Continued)
12–27
Water Shuttles
• According to NFPA® 1901, water tenders on
level ground should be capable of
dumping/filling at rates of at least 1,000 gpm
(4 000 L/min)
(Continued)
Firefighter I
12–28
Water Shuttles
• To fill water tenders quickly, use best fill site,
large hoselines, multiple hoselines
• Multiple portable pumps may be necessary
Firefighter I
12–29
DISCUSSION QUESTION
What are the advantages and disadvantages
of a water shuttle operation?
Firefighter I
12–30
Relay Pumping
• Can be used in situations where water source
is close enough to fire scene to render water
shuttles unnecessary
• Factors to consider
– Water supply must be capable of maintaining
desired volume of water
– Relay must be established quickly
(Continued)
Firefighter I
12–31
Relay Pumping
• Determining number of pumpers needed and
distance between them
– Several factors to take into account
– Apparatus with greatest pumping capacity should
be at water source
(Continued)
Firefighter I
12–32
Relay Pumping
• Determining number of pumpers needed and
distance between them
– Large-diameter hose or multiple hoselines
increase distance, volume a relay can supply
– Water supply officer should consider all factors
and determine correct distance
Firefighter I
12–33
Summary
• Because water is still the primary fire
extinguishing agent used by firefighters in
North America, and because fires often occur
considerable distances from major water
sources, fire departments must develop ways
to transport available water from its source to
where it is needed.
(Continued)
Firefighter I
12–34
Summary
• Firefighters must know what water supply
systems have been developed and what their
responsibilities are when these systems are
used.
Firefighter I
12–35