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HFD E/O Promotional Exam - Fire Service Hydraulics > Chapter II > Flashcards

Flashcards in Chapter II Deck (12)
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1
Q

What is the type of pressure called when pumping down the hill

A
  • forward pressure
2
Q

According to John Freeman how large of a circle should 3/4 of a solid stream past through at its breakover point

A
  • 10”
3
Q

It has been estimated that the momentary nozzle reaction is about ____ higher than the nozzle reaction from the flowing stream

A
  • 20%
4
Q

Which of the following people conducted experiments designed to define what characterizes a good solid stream

A
  • John R Freeman
5
Q

Most fire departments calculate the friction loss for the hoses and nozzles that they carry and write them down on what is called a_________.

A
  • pump chart
6
Q

What is the most widely used formulas for determining friction loss in a 2 1/2” hose line

A
  • Underwriters formula
7
Q

An important thing to remember when figuring friction loss for a combination layout is that hose lines of the same size _____.

A
  • only need to be figured and added once
8
Q

When using the coefficient formula to find the friction loss what is the conversion factor for 3” hose

A
  • .80
9
Q

When changing from a 1 1/2” hose to a 2 1/2” hose, there is ____times less friction loss

A
  • 13
10
Q

In the fire service, friction loss is defined as a loss of __________, whenever water runs through hoses, fittings, and appliances

A
  • energy, in pressure
11
Q

Which of the following formulas was a result of tests conducted by E. M. Byington of the Boston Fire Department

A
  • Nozzle reaction
12
Q

If keeping the flow the same, as a hose size is doubled the friction loss is only _______ times the friction loss in the smaller hose

A
  • 1/32