Chapter 1 Flashcards
What is the Definition of a Cross Connection?
Any actual or potential connection bn a potable water supply / pipe, vessel, fixture, equipment - where it’s possibly for used, polluted, contaminated water chemicals to enter potable water system
What are 5 examples of Cross Connections? (DBJRS)
Direct connections
Bypass connections
Jumper connection
Removable connection
Swivel or change - over device
What is the definition of backflow?
Is the undesirable reversal of a flow in a potable water connection
What are the 2 principle causes of backflow?
1) Back-siphonage
2) Back pressure
What is the definition of Back siphonage?
Backflow caused by pressure below atmospheric in the supply system
What are 2 principle causes of back siphonage?
1) broken water main
2) Open fire hydrant
What is the definition for back pressure?
A pressure higher than the supply pressure
What are 3 common causes of back pressure?
1) Booster pumps
2) Boilers –> thermal expansion
3) Interconnections w/ other systems at high pressure
4) Elevated piping
What is atmospheric pressure?
Is pressure created by the weight of the atmosphere on a surface
What is the number of atmospheric pressure?
14.7 psia (101 kPaA)
What is 1’ water column height?
.433psi / ft WC
What is 1” water column height?
0.0361 psi / in WC
What is Gauge pressure?
Is the pressure read on a gauge
How do you get absolute pressure?
gauge pressure + atm pressure
What is a vacuum?
When the absolute pressure is less than the atm pressure
Gauge pressure is negative
What is Differential pressure?
the difference in pressure bn 2 points
1 imperial gallon = how many pounds?
10lbs
what is the Density of water?
62.4 lbs / cubic foot
What 3 things affect pressure?
1) height
2) density of fluids
3) temperature
What does not affect pressure?
- width / diameter / shape of the container
A building of — height should consider backflow protection
10m (30’)
A broken water main will cause what to happen?
Back siphonage
What are 4 things that cause thermal expansion?
1) boilers w/ potable water make - up lines
2) domestic water hot
3) Glycol loops
4) Solar heating systems
What is the best form of backflow protection?
Air Gap
Something that is written with “mandatory - type” language means what?
It’s not mandatory
ex: CCC = not mandatory
