Pumps

Question 0

What is effective nozzle pressure?

what is it based on

Answer 0

minimum water pressure that will deliver a stream of water to the base of the fire

-based on assumption that pump delivers 25 lbs/square inch from a 3/8 inch diameter hose opening

Question 1

Which kind of hose has more friction?
lined?
unlined?
Lined big inch?

Answer 1

• Unlined hose has more pressure (4lbs/100 ft/30m)
• Lined has half the friction
• Lined Big inch hose has 4lbs/30m due to larger diameter

Question 2

What are the advantages of centrifugal pumps?

disadvantages?

Answer 2

Advantages
-fewer moving parts
-Less susceptible to wear (silt)
-Operates well in tandem
-Does not stall when blocked
-smooth flow
Disadvantages?
-Must be primed
-Requires foot valve in suction
-Requires check valve in discharge
-Less suction than gear pump

Question 3

What is an important aspect of maintenance of hoses.

Answer 3

Check for external abrasion constantly. especially when preparing for use or packing up the hose.

Question 4

What is the pumping equation?

Answer 4

Nozzle pressure = Pump pressure - head - friction loss
where head = elevation difference x .5
and friction loss = 2lbs/100ft lined or 4lbs/100ft unlined

Question 5

Whats a foot valve?

Answer 5

A valve on a suction hose that allows water to go in one way, but not out. This allows the hose to stay primed.

Question 6

Whats a check valve?

Answer 6

another one way valve that goes in after a pump and prevents backflow.

Question 7

What are the 4 main pump setups?

Answer 7

• Standard hose lay
• Short coupled tandem
• Relay pump system
• Gravity system