Ch 11. Static Water Supply Sources

Question 1

The formula for determining maximum lift is:

Answer 1

L= 1.13 hg

L= lift in feet
1.13 = math constant
Hg = inches of mercury

Question 2

Dependable lift is defined as:

Answer 2

Height a column of water may be lifted and sufficient quantity to provide a reliable fire flow.

Every fire pump operating properly should have a dependable lift of 14.7 feet



Question 3

All fire department pumping apparatus are rated when drafting with a minimum lift of ______feet from the center of a pump and take to the surface of the water through _____ feet of hard intake hose

Answer 3

10 feet of lift

20 foot hard sleeve

Question 4

Net pump discharge pressure (NPDP) formula:

Answer 4

PC = lift + total intake hose friction loss
————————————————
2.3

(PC = pressure correction in lbs sq inch)
2.3 = math constant

Question 5

How is theoretical lift calculated?

Answer 5

By determining actual atmospheric pressure of an area and multiplying that number by the waters pressure per square foot while it is in the intake hose.

Question 6

What is the level in feet at which pumpers cannot be expected to draft water?

Answer 6

33.9 feet below the level of the pump

Question 7

What refers to the greatest height to which any amount of water may be raised through an intake hose to the pump

Answer 7

Maximum lift

Question 8

What is the maximum lift in feet in most circumstances?

Answer 8

25 feet

(Pumpers should be able to draw a vac at 22 hg) therefor, lift = 1.13 x 22 hg or 24.8 feet of lift. Approx 25’

Question 9

What happens when the point of maximum lift is approached?

Answer 9

The volume of water available for the fire pump may be too low to be a value for fire suppression

Question 10

In general what type of lift is the driver/operator most concerned with?

Answer 10

Dependable lift

Question 11

How much dependable lift should every operating fire pump have?

Answer 11

At least 14.7

Question 12

What does net pump discharge pressure (NPDP) account for?

Answer 12

All factors that contribute to the amount of work required by a pump to produce a fire stream

Question 13

What is the customary formula for pressure correction?

Answer 13

Lift + total intake friction loss divided by 2.3

Question 14

What is the formula for net pump discharge pressure at draft?

Answer 14

Pumped discharge pressure + intake pressure correction

Question 15

What two factors must be considered when evaluating a potential natural water source?

Answer 15

Adequacy and accessibility

Question 16

And underground water storage receptacle usually found in an area not service by hydrant system is called a

Answer 16

Cistern

Question 17

Large residential, industrial, or agricultural locations may have what type of storage ranging from several hundred to 10,000 gallons of water?

Answer 17

Private water storage tanks