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39 Cards in this Set
- Front
- Back
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Water Distribution History |
1801 - First US water system established in Philadelphia 1881 - Privately owned Tucson Water Company began operating and piping the first water into town. |
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TFD Water Supply Sources |
Static Sources and Pressurized Sources |
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Static Sources |
Any source of water that needs to be mechanically moved into a fire apparatus. -Lakes/ponds/rivers -Portable tanks -Cisterns -Swimming pools -Test Pit |
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Drafting Definition |
The process of raising water from a static water source to the pump. TFD only drafts at the test pit and during water tender shuttle operations. |
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3 things during Drafting |
Lift - The difference between the level of the water and the center of the pump. Vacuum - An enclosed space from which matter, especially air, has been partially removed.
Atmospheric Pressure. |
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Atmospheric Pressure |
The weight of a column of air at a given location on the surface of the earth. 14.7 psi (average) at sea level. 13.9 psi in Tucson |
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More Drafting |
By decreasing the pressure in the pump and hose below atmospheric, the water is forced into the hose. Atmospheric pressure is still pushing on the static water source. The pressure will push the water up the hose. |
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Pressurized Water Sources |
Any water source that will flow freely into a fire apparatus 1. Booster Tanks 2. Water Tenders 3. Hydrants |
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Booster Tanks |
250 GPM to the pump if tank is less than 750 gallon capacity. 500 GPM to the pump if tank is more than 750. |
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Water Tenders |
Carry water to places where there are few or no hydrants. WT20 (8779) carries 2500 gallons of water. |
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Hydrants |
Fire hydrants are part of a water distribution system that is designed to meet the needs of the community which it serves. Hydrants are placed for the specific purpose of providing an adequate and reliable water source for firefighting. |
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Components of a Distribution System |
Supply Source Treatment Plants Reservoirs Mains Hydrants |
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Supply Sources in Tucson |
206 active or standby wells 91 million gallons per day from those wells 57 million gallons per day from CAP CAP aka ClearWater |
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Treatment |
Treated with chlorine at well sites Monitored throughout the system at reservoirs and other sites Additional chlorine can be added throughout the system as needed |
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Reservoirs |
Reservoirs are filled from well sites 57 total reservoirs 29 over 1 million gallons 28 under 1 million |
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Grid System |
Pressure in Grid System is created by gravity from reservoirs at higher elevations and from pumping stations. Advantages: helps reduce dead end mains, reduces friction loss by power of 4, and only one or two hydrants are shut down if a main is broken. |
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Friction Loss |
Total pressure lost in the system while water is forced through pipes, fittings, valves, etc. 1000 GPM through 100' of pipe: 6" main = 52 psi friction loss 8" main = 12.8 psi 12" main = 1.78 psi |
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Main Sizes |
From reservoirs 16" - 56" mains Primary Feeders 16" to 24" Secondary Feeders 12" to 16" Distributors/Laterals 6" - 8" (6 is smallest pipe that feeds a hydrant, 8" if on a dead end main.) |
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Reduced Flow |
Sedimentation - Dirt and other products that collect in system Incrustation - Mineral deposits inside pipes, fittings, valves, etc. Tuberculation - Actual pipe breakdown |
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Zones |
The city must be broken up into zones to prevent too much pressure in the mains due to elevation changes. A pipe laid from Houghton Rd to the Santa Cruz River would create 300 psi at the river (600 - 700 feet elevation change) |
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Zones numbers |
19 zones in Tucson City Limits 105' elevation change within zones Normal pressures in mains will range from 40 to 85 psi Head Pressure = .434 psi per foot of elevation loss (.434 x 105' = 45.6) |
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Zones Stuff |
All zones are connected and separated by valves Valves are computer monitored and controlled |
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Valves |
Function is to simply control the flow of water Two classifications: Indicating (OS&Y, PIV, Ball Valve) Non-Indicating (Gate, Ball, Butterfly, and others) |
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Hydrant Pressures |
Static - pressure in hydrant when it is closed Normal Operating - Pressure found in a water distribution system during periods of normal consumption demand. Residual - Pressure left in system when hydrant is flowing Flow - Pressure of water in motion |
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Hydrant Numbers |
American Water Works Association sets standards Working pressure is 150 psi, factory tested at 300 psi 20,867 hydrants in Tucson Water system 14,324 hydrants in city limits |
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Hydrant Types |
Dry Barrel Wet Barrel |
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Hydrant Mechanisms |
Compression Knuckle Joint or Cory Slide Gate Wet (usually Compression valve) |
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Dry Barrel |
Foot piece Barrel Bonnet Operating Stem Main Valve Drain |
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Compression Type |
Valve moves independently on vertical axis. Seats against the base of the hydrant. Closes with pressure, opens against pressure. Brands: Dresser and Mueller |
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Knuckle and Cory Type |
Scissors type valve Brand: Pacific States and Iowa |
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Slide Gate |
Gate moves vertically on stem Currently TFD has no slide gate style hydrants |
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Wet barrel |
Pressurized at each outlet Outlets are controlled independently with a valve, usually compression |
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High Pressure Hydrants |
Reflective Yellow Bands around barrel 200 psi or greater 95 psi or greater residual pressure DO NOT use 5", use 2 1/2" |
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Hydrant color coding |
Used to be color coded for GPM (Steamer) Green or no paint = 1000 gpm+ Orange = 500 - 999 gpm Red = Less than 500 Tucson Water is painting all hydrant steamers silver now. There are some green orange and red ones left still. |
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Hydrant GPM Flow formula |
29.7 x D^2 x Sq Root of Flow Pressure x 0.9 (co-efficient) D = Discharge diameter (4.5 for steamer cap) Flow pressure from pitot tube and gauge |
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Hydrant Safety |
Open and close slowly to prevent water hammer Never kick a hydrant wrench to open or close a hydrant Make sure hydrant is closed before removing caps Protect all hose from vehicles |
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Hydrant Spacing |
Residential - 800' on 6" main Multi-housing - 500' on 8" main Industrial - 300' on 12" main |
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Fire Codes |
Spacing between hydrants 3' clearance around hydrants Hydrants 2 - 7' from curb Steamer outlet 16" from ground Blue markers |
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Tested |
Tested and maintained by Tucson Water every 4 years Out of service procedure: Hydrant ring, notify fire alarm, email water department, CAD hydrant OOS information displayed |
