Friction Loss And Water Flashcards
Large diameter hose friction loss variance.
2.5 - 3in comparison
3in = three to the 5th
2.5 to the fifth.
Velocity of waters effect on friction loss.
Difference is squared
Twice the velocity 2x2 - tripled 3x3
Pressure variance from source to discharge.
Pressure at source will always be greater
Critical velocity
Point that friction on small diameter hose our nozzle causes too much agitation in stream
Water hammer forces
Force in reverse end of line can be serval time that’s of waters velocity.
Concern of water treatment facilities as source
Power outage and mechanical failure
Circulation feed or looped line
Hydrant that receives water from more than one source.
Less friction loss
Grid system parts
Primary- large main source of lines
Secondary - network of intermittent sized pipes that reinforce grid
Distributors - small connecting lines
Residential line size
6in
Industrial line size
8 in
Minimum line size every ___ feet
8 in line every 600 ft
How often should valves be exercised.
Once a year at minimum
Hollow metal post attached to valve housing.
PIV
Open shut window
Valve with threaded stem that controls gate open and close
OS+Y
Threads out indicate open
Most common valve type
Non indicating valve
Hidden in manholes
