CVFD Training – Water Supply

SFFMA Training Objectives:12-01.01 – 12-01.05

Firefighter I 12–2

Hydrants

• Usually made of cast iron with bronze working parts

• Must be opened and closed slowly to prevent damage

Firefighter I 12–3

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 12–4

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 12–5

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 12–6

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 12–7

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 12–8

DISCUSSION QUESTION

What types of fire hydrant marking systems are used in your area?

Firefighter I 12–9

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 12–10

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 12–11

Hydrant Testing and Inspections

• Responsibility of fire department personnel

• Firefighters should look for wide array of items

Firefighter I 12–12

Fire Hydrant Testing Process

Many departments no longer responsible for testingMost basic test normally conducted is flow test

Firefighter I 12–13

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 12–14

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 12–15

Flow Test Steps

• Use pitot tube, gauge to measure flow rate

• Record pitot gauge reading

(Continued)

Firefighter I 12–16

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 12–17

Flow Test Steps

• Test for vacuum created by operating drain valve (dry barrel)

• Replace cap on outlet• Repeat procedure with each hydrant

Firefighter I 12–18

DISCUSSION QUESTION

What types of situations or areas would require an alternative source of water?

Firefighter I 12–19

Alternative Water Supply Sources

• Lakes• Ponds• Rivers• Ocean• Swimming pools• Farm stock tanks• Underground cisterns

Firefighter I 12–20

DISCUSSION QUESTION

Can you think of any other types of alternative water supplies?

Firefighter I 12–21

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 12–22

Drafting From Alternative Water Supplies

• Depth of water from which to draft

Firefighter I 12–23

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 12–24

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 12–25

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 12–26

Water Shuttles

• Key components• Dump site• Portable tanks

(Continued)

Firefighter I 12–27

Water Shuttles

• Ways in which water tenders unload– Gravity dumping– Jet dumps that increase flow

rate– Apparatus-mounted pumps– Combination of these

methods(Continued)

Firefighter I 12–28

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 12–29

Water Shuttles

• To fill water tenders quickly, use best fill site, large hoselines, multiple hoselines

• Multiple portable pumps may be necessary

Firefighter I 12–30

DISCUSSION QUESTION

What are the advantages and disadvantages of a water shuttle operation?

Firefighter I 12–31

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 12–32

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 12–33

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 12–34

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 12–35

Summary

• Firefighters must know what water supply systems have been developed and what their responsibilities are when these systems are used.