Potable Water Distribution Systems Flashcards
Define Velocity and pressure
Velocity is the rate at which fluid flows
Pressure is the force exerted to the walls of the pipe.
What effect does un reamed pipe have on the flow of water in a pipe?
Turbulence
When does water hammer occur?
When water is forced to change direction or stop suddenly.
List 3 ways to prevent water hammer.
Use shock arresters
Open valves slowly
Air chambers
List 4 causes of water hammer
Quick closing valves
Sudden changes in direction
Temperature difference of liquids
Water stopping suddenly
How do you recharge an air chamber
Drain the system and refill
What 5 things must be known to size a water supply system?
Total developed length of water service pipe
Minimum static pressure at the property line
Length of distribution pipe from building isolation to furthest fixture served
Water pressure at highest fixture served
Total hydraulic load
The minimum working pressure at the fixture is what?
Conforms to the manufacturers specifications
The maximum working pressure at the fixture is what?
Never exceeds 550 kPa static pressure
What table would you find the fixture unit value for a urinal with a direct flush valve?
Sizing of water distribution systems for urinals with direct flush valves.
When sizing multiple water closets with direct flush valves, does the furthest water closet from the distribution supply pipe have the largest or smallest load?
The largest load. This will ensure that the minimum required flow rate is maintained.
What is the minimum air gap required on a lavatory?
25mm or 1”
How must the water supply to pan sinks be protected from back flow ?
Using an approved back flow preventer
How would you find the hydraulic load, fixture units for a commercial dish washer?
Refer to manufacturers recommendations
How do you find the hydraulic load for a 1/2” hose wye?
Use hose Bibb , 1/2” private use fixture unit total from table 2.6.3.2A times 2
Which tables are used to size a water distribution system using the method for small commercial buildings?
Tables 2.6.3.2A 2.6.3.2B 2.6.3.2C 2.6.3.2D A-2.6.3.1.(2)A.
What is the minimum size of the supply line to a water closet using a flush valve?
1”
What term is used to describe the water piping inside a building?
Distribution piping
What is the metric equivalent to pressure expressed as?
KiloPascals (kPa)