8.0 Water Distribution System

Question 1

Service Connections

Answer 1

• The corporation stop/valve is the valve installed on a municipal water main to permit the joining of the water service pipe
• The curb stop is where The municipal water supply system ends (city ownership ends)
• For Single families without fire sprinklers, the service connection size is 19mm, 20mm, or 25mm
• All service connections larger than 50mm in diameter or larger, require a check valve at the property line

Question 2

Valves

Gate valve

Answer 2

• on/off control
• In sections
• Not for flow control or pressure reduction
• The same diameter as the water main up to 300mm diameter
• Not more than 200m apart
• 3 required in X intersections
• 2 required in T intersections

Question 3

Valves

Check valve

Answer 3

• Restricts flow into one direction
• Prevents flowing water to flow back upstream
• Protect upstream equipment and effects of water hammers
• Prevents contamination or mixing (water treatment plan to reservoir)
• Equal diameter as gate valve
• Located in MH or chamber

Question 4

Valves

Air valve

Answer 4

• Hydromechanical devices release gas and admit air into pipelines
• Prevents air vacuum-related issues
• Installed at max. High points 200mm in diameter or larger
• When the difference in ELEV is less than 600mm

Question 5

Thrust block and joint restraints

Answer 5

• Resisting thrust forces in underground water supply systems
• Generated by water motion and pressure changes
• Can be controlled by using different joint restraint methods
• Thrust block=resist horizontal forces
• Thrust anchor=resist vertical forces
• Traditional Push-on joints= secure pipe connections
• Mechanical joints with external restraint= integral mechanisms for very high pressure

Question 6

Fire hydrants

Answer 6

• Not be spaced more than 200m apart
• The principal entrance of buildings to not be more than 100m from the hydrant
• Should be located at intersections
• 1.5m clear from any obstruction

Question 7

Blowdowns

Answer 7

• Maintenance of the operating system
• Flush out sediment at low points
• Required to install when the water main has a diameter larger than 450mm

Question 8

Blowoffs

Answer 8

• Used in the water distribution system
• Remove debris and stagnant water
• Located at deadends
• Fire hydrants can be used as a blowoff (blowoffs are installed where standard fire hydrants aren’t available)
• Flushing ports to be sized to have min.0.8 m/s