Pump Familiarization Flashcards
How can you remove the strainer from the relief valve assembly with the pump operating?
Turn the four way valve off.
Can you remove the strainer from the relief valve assembly with the pump operating?
Yes
Caution: do not turn the pilot valve from “on” to “off” when the pump and engine are turning at ___ speed, the relief valve is ___, and the pump discharge is ___.
High
Open
Low
The pressure relief valve is designed to permit control of pump discharge settings between ___ and ___ psig.
75 and 300
The relief valve cannot control discharge pressure to an amount lower than suction pressure plus about ___ psi.
50
When operating at draft or from booster tank, it will not control at discharge pressures less than about ___ psi.
75
___ shift indicator lights are furnished. ___ are mounted in the cab and ___ on the operators panel.
3
2
1
What parts of a pump are made of:
Body =
Cast iron
What parts of a pump are made of:
Transfer valve =
Bronze
What parts of a pump are made of:
Impellers =
Bronze
What parts of a pump are made of:
Shaft =
Stainless steel
What % of pump capacity can the pump deliver at 15’ and 20’ of lift?
15’: 70%
20’: 60%
What is the maximum psi the electronic transfer valve can operated?
250psi
What is the maximum psi the manual transfer valve can be operated?
75 psi
Manual transfer is approximately how many rotations?
15
Manual transfer clockwise is pump in what stage?
Volume
Manual transfer counter clockwise is pump in what stage?
Pressure
Cavitation protection feature:
The engine speed will automatically return to idle if the pump discharge pressure remains less than ___ psi with an engine speed of more than___ rpm for more than ___ seconds.
30 psi
2000 rpm
5 seconds
What are 3 factors that influence the centrifical pump discharge pressure?
1: amount of water being discharged
2: speed the impeller is turning
3: pressure of water when it enters the pump
When the pressure governor is in the throttle mode, how many rpms is the engine raised when the toggle switch is moved up one click?
25 rpm
Why do pumps have a priming pump?
Because a centrifugal pump cannot pump air, a priming pump is needed to create a lower pressure within the pump and intake hose so that water is forced up into the pump by atmospheric pressure.
What type of priming pump does the Pierce pumper use?
Positive displacement pump, rotary vane type
Compound gauge:
What is it and how does it work?
Connected to suction side of the pump. It registers pressure above atmospheric in psi and below atmospheric in inches of mercury.
Discharge gauge:
What is it and how does it work?
It is connected to the pressure side of the pump. It registers pressure above atmospheric in psi.
What is atmospheric pressure at sea level?
14.7 psi
What is atmospheric pressure as you go up in elevation?
Decreases 1/2 lb. per 1000’ rise in elevation.
Determine Net Pump Pressure:
From a pressurized water source?
Pump pressure gauge - suction gauge = NPP
Determine Net Pump Pressure:
When drafting?
Pressure gauge + suction gauge = NPP
Define net pump pressure.
Net pump pressure is the total work done by the pump to get water into, through, and out of the pump, hoses, and nozzles. It is the sum of pump pressure, suction and lift losses.
What are the signs of pump cavitation?
- Increasing pump speed without corresponding increase in volume or pressure
- Excessive pump vibration
- A rattling sound resembling gravel going through the pump
How can you fix pump cavitation?
Reducing pump speed or improving intake conditions will usually eliminate cavitation.
Define cavitation.
Cavitation is when the pressure on the water in the pump falls below it’s vapor pressure and begins to form bubbles. These bubbles are carried into the high pressure regions of the pump where they collapse with considerable force. It sounds like gravel inside the pump.
When does cavitation occur?
It is caused by operating a pump at excessive speed, too high an intake lift, or restricting the intake.
The two main parts of centrifugal pumps are the ___ and ___.
Impeller
Volute
The normal leakage for the pump packing is ___ - ___ drops per minute.
10 - 120
Intake screens get checked for excessive corrosion ___ and the anodes are checked ___.
Monthly
Twice a year
Many pump operators set the pilot valve about ___ psi above the intended discharge pressure to prevent minor pressure surges from opening the relief valve.
5
Turning the handle clockwise will ___ the set pressure.
Increase
The minimum size fuel tank in a “Class A” pumper is ___ hours capacity.
2
How many feet will 1 psi raise a column of water?
"Head Pressure"
2.304 feet
What does psig mean?
Pound per square inch gauge
14.7 plus psi
When shifting from pump to road, after moving pump shift control to “road”, wait at least ___ before engaging road transmission.
4 seconds
When the pressure governor is in the pressure mode, how many psi is the discharge pressure raised when the toggle switch is moved up one click?
4 psi
What is the maximum pressure pumped to a 5” supply hose during the annual hose test and during fire ground operations?
Hose test: 200psi
Fire: 185psi
The system shut down switch can and should be used to return the engine speed to idle when operating in ___ or ___ water flow conditions.
Low
No
Because of the differences between throttle and pressure mode ramping increments, the operator will find that a desired discharge pressure value can be obtained more quickly by increasing engine speed in the ___ mode.
Throttle
The governor control system will automatically initialize in the throttle control mode after the ___ has been activated and the transmission is placed in the ___ position.
Parking brake
Neutral
The ___ control mode is achievable ONLY if the pump is engaged.
Pressure
The LDH pressure relief valves are set at ___ psi for intake relief and ___ psi for discharge relief.
80
185
Turn the screw ___ and the pressure will increase.
Clockwise
Turning the screw ___ will decrease the pressure.
Counter clockwise
A Waterous priming system consists of three components: ___, ___, ___.
- Positive displacement priming pump
- A priming valve
- Priming tank
If high pressure is required (more than ___ psi) operating the pump in the ___ position may be necessary even if it means closing one or more valves to reduce ___ and avoid ___.
200 psi
Pressure
Volume
Cavitation
Keep the pump transfer valve in the ___ position when pumping up to 2/3 of the rated capacity of the pump and in ___ when pumping more than 2/3 of the rated capacity.
Pressure (series)
Volume (parallel)
___ ___ ___ intake screens are normally used in the intake fittings. They will help prevent ___ in the rest of the pump.
Zinc die cast
Corrosion
Monthly Vacuum Test:
Operate priming device to create a vacuum of about ___ in/Hg.
22 in/Hg
Monthly Vacuum Test:
The vacuum shouldn’t drop more than ___ in/Hg in ___ minutes.
10 in/Hg in 5 min
Monthly Vacuum Test:
Priming device should prime readily in ___ seconds for a 1500 - 2000 gpm pump.
45 sec.
Always reduce pressure with engine ___ before turning four way valve ___.
?
