Flashcards in Chapter 11- Operating Fire Pumps Deck (10):
To avoid possible damage to the water system, the intake pressure should not drop below _____psi?
If it is necessary, can you drop below the recommended minimum intake pressure level? What is that level?
Yes, if necessary you can drop below 20 psi, but you shouldn't drop to zero.
Types of hydrants: Class, Color, Flow
AA. Light Blue. 1500 or greater
A. Green. 1000 to 1499
B. Orange. 500 to 999
C. Red. Below 500
What is the definition of static pressure?
When a pumper is connected to a hydrant and is not discharging water. That pressure is static pressure.
What is the definition of residual pressure?
When the pumper is discharging water, the intake reading is the residual pressure.
How do you determine how much more water the hydrant can supply?
The difference between the static pressure and the residual pressure is used. There are three methods.
1. Percentage method
2. First digit method
3. Squaring the lines method
One foot of lift equals ??? Inches of Mercury?
One foot of lift equals 0.885 inches Mercury
Maximum theoretical lift is?
Relationship between atmospheric pressure and psi?
Atmospheric pressure drops .5 psi per 1000 feet