Hydraulic Trouble shooting, math, fluid seals test

Question 1

when troubleshooting a hydraulic system on site you would

use a schematic of the system

ask a journeyman for help

talk with the operator

all the above

Answer 1

All of the above

Question 2

when troubleshooting a hydraulic system on site you would

use a schematic of the system

ask a journeyman for help

talk with the operator

all the above

Answer 2

all of the above

Question 3

if a hydraulic pump has lost some of its efficiency you would know this by

slow moving actuators

loss of pressure

excessive oil flowing thru the pump’s drain line when tested

both the first and 3rd answers

Answer 3

Both the first and third answers are correct

Question 4

Areation is caused by?
-entrained air bubbles in the oil
- Leaking pump seals
- to much oil in the tank
- all of the above

Answer 4

leaking pump seals

Question 5

Cavitation which is distinguished by a rattling noise is checked by?
- Looking for a clogged inlet
- Installing a vaccum gauge on the pressure line
- installing a flow meter on the drain line
- All of the above

Answer 5

looking for a clogged inlet

Question 6

Misaligned couplings lead to?
- loose mounting bolts
- broken drive shafts
- vibration
- all of the above

Answer 6

all of the above

Question 7

an axial piston pump with a variable displacement could have ______ if the flow or pressure was low?
- The pressure or load sensor out of adjustment
- A blockage in the pilot port to load sensor or compensator
- all of the above

Answer 7

all of the above

Question 8

low output speed of an actuator could be caused by?
- A volume control valve
- A pressure reducing valve
-A directional control valve
-All of the above

Answer 8

A volume control valve

Question 9

an AC solenoid can burn out and can be noisy (hum)

true

false

Answer 9

true

Question 10

To test a directional control valve for proper actuation, you could

push the armature pin or manual override to see if the actuator moves

see if the hoses jump when the valve is energized

see if the light comes on at the end of the directional control valve when it is energized

all the above

Answer 10

all of the above

Question 11

a compound (pilot operated) relief valve has ___________then a direct acting

a higher override

less stages

lower pressure override

all the above

Answer 11

lower pressure override

Question 12

a most likely problem with a relief valve is a broken spring

true

false

Answer 12

True

Question 13

a pressure reducing valve is a normally closed valve. (senses pressure up stream of the valve

true

false

Answer 13

False

down stream of the valve

Question 14

a sequence valve has an external drain line to the tank

true

false

Answer 14

True

Question 15

a counterbalance valve that will not let the load lower has what type of problem

broken spring

worn valve

incorrect adjustment (set to low)

incorrect adjustment (set to high)

Answer 15

Incorrect adjustment (set to high)

Question 16

after installing a flow control, the speed of the actuator is slow in the wrong direction. the problem is

dirt on the valve seat

incorrect adjustment

worn throttle spool

valve installed backwards

Answer 16

Valve is installed backwards

Question 17

to test a cylinder for leaks, pressurize either end and see if any oil comes out the other end.

true

false

Answer 17

True

if oil comes out it means oils is flowing past the piston

Question 18

if a cylinder has jerky movement or is squealing, the most likely cause would be aeration

true

false

Answer 18

True

Question 19

hydraulic motors that are not producing full torque (pressure) have what kind of problem

internal leakage

shaft seal leaks

relief valve set to low

all the above

Answer 19

Relief valve set to low

other answers are flow issues not pressure

Question 20

when troubleshooting hydraulic systems, the things to look for to solve the issues are

pressure

speed

heat

all the above

Answer 20

all of the above

Question 21

to help troubleshoot a system you need to know how the system works

true

false

Answer 21

True

Question 22

a tachometer will help you troubleshoot what type of issues

flow

speed

pressure

both the 1st and 2nd answer

Answer 22

flow and speed

Question 23

pressure gauges are protected from damage (from pressure spikes) by the use of snubbers

true

false

Answer 23

True

Question 23

if you were checking if there was any flow going over the relief valve, you would use a

flow meter on the outlet side of the relief valve

temperature gauge on the pump

flow control at the actuator inlet

none of the above

Answer 23

Flow meter on the outlet side of the valve

Question 24

particle counters count particles at 3 different micron ratings. they are 2, 5, 10 2, 10, 20 4, 6, 14 or 2, 5, 15 2, 4, 14

Answer 24

4,6,14 or 2,5,15

Question 25

when troubleshooting electro-hydraulics with a servo valve, you would know it would be an open loop system be a closed loop system be controlled by air not have feedback

Answer 25

Be a closed loop system

Question 26

servo valves have amplifier cards that convert an electronic signal from the feedback device to the servo valve____________________ torque motor encoder transducer tachometer

Answer 26

Torque motor

Question 27

when troubleshooting a system with many branches or circuits within the system, you would use a schematic with a solenoid chart to help resolve the issue(s) true false

Answer 27

True

Question 28

a common fault with servo valve systems that make them inoperable is a plugged filter. true false

Answer 28

True

Question 29

a starting point to solve hydraulic issues when a system is not working properly is to talk to the operator running the system true false

Answer 29

True

Question 30

what is the force(lbs) if 500 psi is applied to the low pressure side of an intensifier cylinder? the area on the input side is 10 sq in and the output piston is 1 sq in 500 100 2500 5000

Answer 30

5000

Question 31

what is the load the porta-power system will lift. m.a. of handle=15/1, piston d=0.5", ram D=3", E=50 lbs 27,000 lbs 12,000 lbs 17500 lbs 22500 lbs

Answer 31

27000 lbs

Question 32

calculate the HP required to drive a pump in a hydraulic cylinder hydraulic system with the following specifications. ram piston diameter=3", piston rod diameter=1.5", return stroke force= 6000lbs, return stroke speed= 350 in/min 7.4 6.2 4.8 5.3

Answer 32

5.3

Question 33

a hydraulic hoist must not lift any vehicles over 5000 lb. the piston diameter=10". what is the relief valve set at. 59.2 psi 63.7 psi 45.9 psi 77.7 psi

Answer 33

63.7

Question 34

you have a system with a 35 hp motor and a 20 gpm pump. the cylinder diameter=3", hydraulic tubing tensile strength is 55,000 psi, the steel tubing has a 3/4" outside diameter with a wall thickness of 0.109". what is the maximum line pressure if it has a safety factor of 6. 2777 2664 5854 2864

Answer 34

2664

Question 35

use the following information to calculate the effort needed. d=0.554", D=3.25", L= 3050 lbs, LD = 0.255" 74.4 lbs 66.6 lbs 88.6 lbs 59.2 lbs

Answer 35

88.6

Question 36

what amount of torque is being produced if the system has a 25 gpm pump turned by a 1200 rpm electric motor and a hydraulic motor creating a pressure of 1770 113 ftlbs 75 ftlbs 243 ftlbs 413 ftlbs

Answer 36

113 ft/lbs

Question 37

what diameter of cylinder will be needed to lift 5500 lbs with a pressure of 1000 psi 2.5" 2.75" 3" 3.25"

Answer 37

2.75

Question 38

when troubleshooting a hydraulic system, you find a slow actuator acting against the full force in the system. the problem would not be the pump wearing out damaged seals in the actuator flow control restricting to much system relief valve set above pump operating pressure

Answer 38

system relief valve set above pump operating pressure

Question 39

when troubleshooting a hydraulic system, you find to low of a pressure. it could be pressure reducing valve set to low pressure relief valve set to high pressure relief valve set to low both the first and 3rd answers are correct

Answer 39

Both first and third asnwers

Question 40

if you have erratic movement in your actuators it is a sign of erratic pressure air in the fluid no lubrication on machine ways or linkage all the above

Answer 40

all of the above

Question 41

if you had a hydraulic system that ws overheating and had excessive noise at the pump, the problem would likely be fluid viscosity to high excessive pump speed and load dirty inlet filter all the above

Answer 41

all of the above

Question 42

if you found a hydraulic motor with a broken shaft, the problem could be caused by system pressure overload misalignment failed bearing all the above

Answer 42

all of the above

Question 43

excessive heat in a hydraulic system could be caused by proper fluid viscosity and proper oil oil bypassing a filter relief valve stuck partly open both the 2nd and 3rd answers are correct

Answer 43

Both second and third answers are correct

Question 44

o low of a flow rate and to low of system pressure could be caused by the relief valve setting being to low true false

Answer 44

True

Question 45

excessive pressure in a hydraulic system would be caused by a pressure relief valve with a broken spring true false

Answer 45

False

Question 46

valve issues found when troubleshooting can be any of the following. spool sticking, defective O-rings and a burnt out solenoid true false

Answer 46

True

Question 47

invisible leaks on cylinders are between the piston and the cylinder wall and between the rod and cylinder wall true false

Answer 47

True

Question 48

erratic pressure could be caused by a defective accumulator or one that has lost its charge of nitrogen into the fluid true false

Answer 48

true

Question 49

the MAIN function of hydraulic fluid is to transmit power from the pump to the actuator lubricate moving parts seal clearances carry heat and contaminates away

Answer 49

Transmit power from the pump to the actuator

Question 50

petroleum based hydraulic fluids are used most frequently because low cost readily available good lubricating qualities all the above

Answer 50

all of the above

Question 51

water based fluids that are glycol - based should have the pump mounted below the fluid level because the weight of it is heavier than water true false

Answer 51

true

Question 52

synthetic oils are being used more and more because they have a high resistance to oxidation a high viscosity index longer life all the above

Answer 52

all of the above

Question 53

vegetable oils such as soy oil are used when there are environmental considerations to take into account true false

Answer 53

true

Question 54

store hydraulic fluids so the fluid is protected from the elements and the environment is protected form the fluid true false

Answer 54

true

Question 55

the baffle in a hydraulic tank keeps oils separated keeps the water from getting into the oil allows the mixing of the additives slows the fluid down

Answer 55

Allows fluid to slow down

Question 56

the inlet filter should be about _____________ and have a _____________ for safety 100 microns, bypass 3 microns, bypass 100 microns, check valve

Answer 56

100 microns and bypass

Question 57

the return line outlet should be ______________ the fluid level and the angle of the cut (of the pipe) should be___________ the path to the pump inlet above, facing below, facing away from above, facing away from below, facing

Answer 57

Below facing away from

Question 58

to help save the environment from major spills, you can use level indicators and automatic shut-offs to control the amount of oil lost true false

Answer 58

True

Question 59

water coolers are more efficeint than air coolers as they can control the temperature mor accurately true false

Answer 59

True

Question 60

the breather cap on top of the reservoir allows atmoshperic pressure in to push on the oil when the pump is creating a vacuum true false

Answer 60

True

Question 61

reservoirs that are vented use ___________________ to help push the oil into the pump supplied air pressure atmospheric pressure no air pressure all the above

Answer 61

Atmospeheric pressure

Question 62

if you have a closed circuit reservoir, you would use about ______________ psi 10-15 5-10 1-3 25-50

Answer 62

1-3

Question 63

a hdyraulic tank that has the pump mounted inside the tank is the flat top L-shaped overhead stack vertical mount

Answer 63

Vertical mount

Question 64

about 80 % of hydraulic component failures are due to____________ contamination lack of lubrication leaky seals industrial mechanic errors

Answer 64

Contamination

Question 65

filter carts can transfer oil to the reservoir clean the oil empty the reservoir all the above

Answer 65

All of the above

Question 66

the type of contamination that gets into the system from the outside is built-in ingressed generated wear related

Answer 66

Ingressed

Question 67

a micron is equal to 1 millionth of a meter true false

Answer 67

true

Question 68

when setting IOS cleanliness targets for a hydraulic system, you know they are being attained by proper filter systems using a portable partical counter visually inspecting them oil changes at frequent intervals

Answer 68

Using a portable particle counter

Question 69

it is necessary to have a bypass valve on a filter to protect the filter element from collapse protect the system from not getting the proper amount of oil protecting the pump from cavitation all the above

Answer 69

All of the above

Question 70

the pleated fiberglass filter is supported by a diffuser layer filter media metallic mesh none of the above

Answer 70

Metallic mesh

Question 71

depth type media consists of __________________ that capture dirt matrix of fibres clay charcoal fullers earth

Answer 71

Matrix of fibers

Question 72

all hydrauic systems should have a filter located in the pressure line return line pressure line before the DCV after the cylinder

Answer 72

Return line

Question 73

beta ratio is the efficiencey of the hydraulic system efficiency of the pump efficiency of the filter volumetric efficiency of the pump

Answer 73

Efficiency of the filter

Question 74

to select the proper filter for your system, you would use a filter placement chart or manufactures recommendation. true false

Answer 74

True

Question 75

maintenance of hydraulic fluid would include water contamination protection heat protection oxidation protection all the above

Answer 75

all of the above

Question 76

dynamic O-rings have the same amount of squeeze as the static O-rings true false

Answer 76

False

Question 77

for every 10 degrees C above 60 degrees C, the oxidation rate tripples doubles quadruples none of the above

Answer 77

Doubles

Question 78

O-rings in hydraulic systems can be used as dynamic seals true false

Answer 78

True

Question 79

never add sealant to the first 2 threads (from the end of the pipe) as it could add contamination into the system true false

Answer 79

True

Question 80

to help tighten a loose fitting high pressure lip seal, you could add loctite to the inside of the housing where the seal sits true false

Answer 80

True

Question 81

always use emery cloth in a perpendicular motion (not spiral motion) around the shaft to help stop spiral leaks true false

Answer 81

True

Question 82

an accumulators MAIN function is to absorb shock even out pulsations protect against over-pressure store pressurized fluid

Answer 82

Store pressurized fluid

Question 83

you should NOT use a flared fitting in a _______________ environment dirty hot slippery high vibration

Answer 83

High Vibration

Question 84

flareless fitting are used with thin walled tubing thick walled tubing both the 1st and 2nd answer noe of the above

Answer 84

Thick walled tubing

Question 85

when tightening flared fittings (after tightening hand tight) use a flare (tube) wrench and tighten 1/4 turn for fittings under 5/8" and 1/8 of a turn for sizes over 5/8" true false

Answer 85

True

Question 86

when troubleshooting a pump cavitation issue at the inlet, the pressures you will be looking at will include both vacuum and atmospheric pressures true false

Answer 86

True

Question 87

when installing hydraulic hoses, make sure to ______________ to make sure they are installed properly have a slight twist in the hose no twist in the hose the hose is stretched slightly the hose has the fredom to whip around

Answer 87

No twist in the hose

Question 88

if you see blisters in the outer rubber layer of a hose this tells you that the oil has been over-heated there is oil leaking thru the reinforcement the iner-tube is comming thru the reinforcement it is normal to have some blisters

Answer 88

There is oil leaking through the reinforcment