Private Water Supply Pressure System Components 060401c Flashcards
What is the primary component of a private water system?
The pump
What are the standard air to water ratios in a pressure tank?
1/3 air 2/3 water
A pressure tank that contains 1/3 air and 2/3 water at 40 psi will what % of its water before the pump needs to start again? What is this water called?
20%
Usable water (draw off)
Most pressure tanks are a minimum of how many gallons?
42
On a pressure tank installation requiring air to be replenished, the two most common air volume controls are what?
- float type
- diaphragm type
How do the pressure switch adjustments on the small screw change the dynamics of the switch?
Counter clockwise lowers cut-out
Clockwise raises cut-out
How do the pressure switch adjustments on the large screw change the dynamics of the switch?
- Clockwise to increase both cut in/cut out
- Counter clockwise to decrease both
Pressure relief valves should be set how much higher than the cut out pressure of the pressure switch?
10 psi
A pressure expressed in terms of height of a water column in feet
Head
A measurement expressed as a volume per a specific period, such as gallons per minute
Flow rate
1 psi will raise a column of water how much?
2.31 feet
How many psi create one foot of head?
0.433 psi
How do you convert psi to feet of head?
Multiply by 2.31
50 psi x 2.31 = 115.5’ of head
How do you convert feet of head to psi?
Multiply by 0.433
115.5’ of head x 0.433 = 50.127 psi
The requirement placed on the pump to deliver the water to the point of use at an effective pressure and volume?
Total head
