Water Supply And Hydrants Flashcards
Types of water supplies
Static supply (open) dam,river,pond etc
Access via draughting
Reticulated supply (closed) accessed via hydrants
Trunk main
Water source to treatment. Then source reservoirs
Pipes 600mm- 3000mm
Service mains
From reservoirs to various pressure zones.
Have shut off valves
Generally runs between foot path and road
Pipes 100mm-600mm
Have hydrants fitted every 90m
Ring main
Run completely around area and coupled back to main supply
Water runs both directions so possible flow is increased.
Contains shut off valve so that if part is damaged, flow can still be achieved
Installed at areas of high risk. Hospitals prisons etc
Pressure is..
The force at which water is delivered
Pressure is effected by..
Length of main between reservoir/tank/pump/hydrant
Pumping stations/booster in system
Number and size of hoses/appliances attached
Quantity being used by other consumers
Flow is..
The quantity of water being delivered
Flow is effected by..
Diameter of mains
Condition of internal surface
Pressure at which main is operating
Types of hydrants
Spring valve
High capacity
Pillar
Spring valves are..
Buried in hydrant pit
Need a stand pipe to access
500mm- 5m from road
Location of spring valve
Blue cats eye
FH placard
Match stick
Comms
MDT
High capacity are
Yellow
Two 64mm storz connections
One 125mm storz
Needs high capacity key to operate
Found in areas of high risk
Replaced with groupings of spring valves
Pillar hydrants
Mostly decommissioned
If decommissioned spring valve installed next to
Heritage value
Need pillar hydrant key
What is water hammer
The shock wave which is transmitted through column of water in a pipe or hose when flow is suddenly cut off
How to avoid water hammer
Slow controlled close off or branches,hydrants,deliveries.
If vehicles need to drive over hoses, do so slowly
What is a booster
Allows brigade appliances to connect to internal hydrant systems of buildings to boost pressure
Booster boxes have
Access to mains in or near by
2x64mm inlets
Block plan of structure
Sign showing test pressure and max op pressure
Internal hydrants are..
Pre 1994 within 4m of fire stairs
Post 1994 in fire stairs
Any building greater than 4 floors
2 or more basements
Have a stair press
Attack hydrants
Located on ring main
How is pressure effected
Length of main between reservoir/tank/pump and hydrant
Pumping stations/booster pumps
Number of hoses/appliances
Other consumers
How is flow effected
Diameter of main
Condition of internal surface
Pressure at which main is operating
Standpipe parts
Hand wheel
Spindle
Head
Storz coupling
Shut off handle twin outlet or single
Barrel
Lugs
Threaded collar
Operating a booster
Attach atleast two lines of collector
Attach two 64mm deliveries
Gradually increase pressure until 800kpa is achieved
Clear and accurate comms between pump operator and branch operator vital
