Pump Theory

Question 1

True or false

When pumping in series a pump will delevop twice the pressure at half the volume

Answer 1

True

Question 2

List the reasons stated by the AOTM for switching to series to parallel or vice visa…

Answer 2

1. ) long single line use pressure
2. ) short lines high with big tips, use volume
3. ) or which ever will give you desired result with lowest engine speed

Question 3

AOTM states that particular attention should be taken when switching from series OR parallel ?

Answer 3

Switching from parallel to series because in theory you can double pressure

Question 4

AOTM states that theoretical pump capacity can be exceeded How?

Answer 4

Help from hydrant pressure

Question 5

AOTM states the all pumps purchased by Lafd conform to the NBFU rating….what is that rating?

Answer 5

100% rated capacity at 150 pounds net pump pressure
70% rated capacity at 200 pounds net pump pressure
50% rated capacity at 250 pounds net pump pressure

Question 6

The AOTM states that the engine shall be capable of performing the pumping tests specified without exceeding the certified governed speed and also have an additional what %?

BONUS - what is this test known as?

Answer 6

10%

BONUS - spurt test

Question 7

AOTM states the acceptance test pressures shall be taken ______ and not ________

Answer 7

At the outlets and not center of the volute

Question 8

AOTM states that the pump shall be capable of pumping ____% overage on gallons per minute at ____psi in “capacity” position

Answer 8

10%

150 psi

Question 9

Failure of pump to deliver rated capacity and pressure may be an indication that pump wear rings’ are badly worn.

True or false

Answer 9

True

Question 10

AOTM States that atmospheric pressure is less at lower altitudes.

True OR false

BONUS - what is normal atmospheric pressure?

Answer 10

False - atmospheric pressure is greater at lower altitudes.

BONUS - 14.7 or 29.92 inches of mercury

Question 11

Which of the following are reasons why cavitation occur, according to the AOTM :

1) excessive lift
2) too small or too long suction hose
3) blocked or inadequate suction strainer
4) pumping unusually warm water
5) pumping unusual low atmospheric pressure (high altitude)

Answer 11

All of the above

Question 12

AN INCREASE IN ENGINE RPM WITHOUT A CORRES-PONDING INCREASE IN PRESSURE INDICATES CAVITATION.

True OR false

Answer 12

True

Question 13

Most compound gages are difficult to read and are often inaccurate on the vacuum scale, according to the AOTM.

True OR false

Answer 13

True

Question 14

According to the AOTM, what is the best way to observe cavitation?

Answer 14

A better way is to observe the point at which speed increases without an increase in pressure.

Question 15

CAVITATION WHEN PUMPING FROM A HYDRANT IS NOT COMMON.

True OR false

Answer 15

False - cavitation is common when pumping from a hydrant

Question 16

According to the AOTM, what is the 3 phase program for maintenance?

Answer 16

Preventive, periodic and inspection tests

Question 17

According to the AOTM, which preventive maintenance will determine the actual condition of the pump?

Preventive maintenance, periodic maintenance or inspection tests?

Answer 17

Inspection tests

Question 18

How do you preform a vacuum test?

Answer 18

Close discharge gates, drain valves and operate priming pump to achieve 22 inches of mercury. Stop priming pump and engine and observe. Wait 10min and look for drop of 10inches or thereabout. Record or report findings

Question 19

According to AOTM, a prime should be achieved in less than ___seconds.

Answer 19

30 seconds

Question 20

What are the 3 types of gauges found on pumps, according to the AOTM?

Answer 20

Vacuum , pressure and compound

Question 21

According to the AOTM, compound gages are found on the suction side of the pump.

True OR false

Answer 21

True

Question 22

What type of gauges are found on pumps, according to the AOTM?

BONUS -what types are there and what are most common?

Answer 22

Bourdon type

Bonus - single and double spring, single spring is most common now

Question 23

According to the AOTM, which gauge is one of the most important?

Answer 23

Ammeter - because of the number of other gauges that use power to operate.