Hydraulics- Pumps- Hoses Flashcards
1
Q
Rotary pumps are what type of displacement?
A
positive displacement
2
Q
What is the most common type of rotary pump?
A
the gear type pump
3
Q
What are the 5 types of rotary pumps?
A
Gear, vane, screw, sliding shoe, multiple piston
4
Q
What may result from improper design, excessive suction lift, improper piping
A
cavitation
5
Q
What are the disadvantages of a centrifugal pump?
A
suction lift and sensitivity to head and speed
6
Q
What is the best and most modern way to align pumps?
A
laser optical
7
Q
Shelf life of hoses
A
10 years
8
Q
Flexible hoses must not be twisted during installation because
A
The service life of the hose would be reduced and fitting may become loose
9
Q
What happens to flexible hose under pressure?
A
length contracts and diameter expands
10
Q
Beta 5 = _____ the removal of what %?
A
Beta 5=10 removes 90%
11
Q
Beta 10 = ___ removes what %?
A
beta 10 = 50 removes 98%
12
Q
What are the 4 basic types of hydraulic pumps
A
Vane, piston ,gear, screw
13
Q
What is the most common liquid contamination of hydraulic fluid?
A
Water
14
Q
What are the five flow control valves?
A
Stop, globe, needle, Gate, plug cocks
15
Q
at what contamination level will water show cloudiness in hydraulic fluid?
A
Cloudiness at .03%
16
Q
What is the max allowable water content in hydraulic oil?
A
500ppm
17
Q
What pump is seldom used, simplest of pumps, 600 psi or less?
A
Gear pump
18
Q
What pump is rugged and highly efficient, range of 6,000 PSI or more?
A
Piston
19
Q
What PUMP IS EFFICIENT AND Small 2,000 psi?
A
Vane
20
Q
What pump is used for power transmission in sub 3,00 psi?
A
Screw
21
Q
Hydraulic motors are commonly used with what type pumps?
A
Vane and piston
22
Q
What is pressure?
A
The direct result of resistance of fluid flow
23
Q
What chapter of the M9000 is the flex hose program?
A
505 flex hose program
24
Q
Hose slack in a hydraulic hose should be between?
A
5-8%
25
When making a hose tag what should be on the tag?
Replacement date
26
What is cavitation?
When absolute static pressure drops below the liquid's vapor pressure
27
What is done for BECCE’s to prevent damage from a too realistic scenario?
Dry run
28
What percentage of working pressure do you test a temporary hose to?
200%
29
Which hose is not part of a hose log?
Outboard hoses
30
When do you change hydraulic oil?
every 500 hours of operation
31
What position do vanes get stuck in?
Retracted position
32
What are the 4 positions of a DCV?
Open, Closed, Floating, tandem
33
When grit or debris is caught in a vane pump what happens?
Vane is stuck in retracted position
34
The difference between inlet and outlet pressure at full flow (rated capacity)?
Full flow differential pressure(set pressure)
35
Cavitation in piston pump on initial startup?
Restricted inlet to the pump
36
Hydraulic strainers are located where?
Before pumps or at the reservoir fills
37
Hydraulic filters are located where?
after the pump, return line, before entering the reservoir, and bypass loop
38
What is the most desirable flow in a hydraulic system?
Laminar flow
39
What is the least desirable flow in a hydraulic system?
Turbulent flow
40
How often do you check viscosity in hydraulic oil?
Systems used daily-check semi annually or
| any less check annually
41
What is the greatest effect on viscosity in hydraulic oil?
Heat
42
Selecting the correct hydraulic connector or fitting depends on what?
Fluid mediation
43
A fitting in a hydraulic hose can be connected in which ways?
Crimped or swaged
44
What is the preferred viscosity index for most hydraulic systems?
90 above
45
Viscosity is measured how?
Saybolts universal or saybolt universal seconds
46
In the CG what is the most commonly used Hydraulic fluid
Navy Standard hydraulic oil
47
What are the 4 main requirements of fluids in hydraulic systems?
Transmit power, cool , seal, and Lubricate
48
Hydraulic oil shall be sampled at least
monthly or Semi annually
49
Hydraulic oil shall be exercised at least ?
15 min Quarterly
50
What classification letter does ships hydraulic tanks have?
F
51
In hydraulic oil testing and analysis what is an ISO cleanliness code?
3 digit code that indicates the amount of micron particle size
52
Two types of lubricating films that exist within a hydraulic system?
full film and boundary lubrication
53
What is it called when metal components are completely separated by a lubricating film?
Full film
54
When some metal is metal to metal contact due to tolerances its called
Boundary lubrication
55
What IS THE MOST COMMON HYDRAULIC ACCUMULATORS IN THE CG
Gas charged with nitrogen
56
What component absorbs hydraulic shock and stores fluid under pressure as an auxiliary energy source
an accumulator
57
After a hydraulic oil change how many hours do you have to wait to sample the system?
25 hours
58
What are the 2 types of hydraulic filters?
Surface or depth
59
This component diverts fluid to a second actuator or motor to do work in another part of the system
Sequence valve
60
How long do you test a hydraulic hose for
5 min a twice the operating pressure
61
What is a common problem with piston type hydraulic actuators
external leakage
62
How does hydraulic fluid get cooler
the reservoir
63
What is the most common cause of hydraulic system failures?
Contamination
64
What happens to a hose under psi?
Contracts in length, expands in width
65
If a pump creates flow what creates resistance?
pressure
66
What affects hydraulic oil sealing ability?
Viscosity
67
most common type of hydraulic fluid
petroleum based
68
If you have a bearing failure on a centrifugal pump with excessive vibration what is the likely cause?
Misalignment
69
What are the disadvantages of the centrifugal pump?
cannot self prime, poor suction lift
70
What are the two classifications of centrifugal pumps?
Single stage and multistage
71
What chapter is compressed air in the NSTM
NSTM chapter 551
72
The three classifications of impellers are
open, closed, and semi closed
73
A measurement exceeding ___ inches would indicate excessive runout
.002”
74
If you have no display on your RCS what should you check?
Voltage
75
what do vacuum gauges read in
HG
76
Hydraulic systems sense a certain pressure and directs the flow back in the?
unloader valve
77
what is the most commonly used hydraulic motor
fixed displacement piston type
78
hydraulic shock can be reduced by using what component in the line upstream by using a
pressure snubber
79
What percentage of hydraulic failures are due to contamination?
80%
80
How long do you test a hydraulic hose?
5 min
81
What pressure do you test a hydraulic hose at?
twice the rated pressure
82
What is the diameter of the -10 hydraulic hose?
⅝
83
What is the inside diameter of a -12 hydraulic hose?
¾
84
what IS THE DIAMETER OF A -16 hydraulic hose
1 inch
85
What are the two types of hydraulic reservoirs?
vented/pressurized
86
the most common type of media for coarse filtration is
surface media
87
what is the acceptable leakage rate for screw type hydraulic pump shaft seal?
50ML
88
what is the max water in hydraulic fluid
500 ppm
89
how much water PPM is acceptable in petroleum based hydraulic oil
130-250 ppm
90
According to NSTM 556 a desirable level of water is ?
100 ppm or .01
91
what is the most common type of reservoir
vented
92
tested PH levels in a hydraulic fluid should be
8.2-10.0
93
thief samples should only be taken if the system ?
cannot be operated
94
EPA generator training how often
Annually
95
If a pressure gauge reads 0, what is the normal reading of the gauge?
14.7
96
what is atmospheric pressure at sea level
14.7
97
One bar is equal to
14.5
98
How much does one inch squared column of air weigh if it reached as high as the atmosphere?
14.7
99
Temperatures in a hydraulic reservoir shall be maintained over what temp?
110 deg
100
The contractor must present the CG with a Weight handling certificate?
Presented to KO at the arrival conference
101
Lifting equipment shall be tested to ?
125% of the weight of the vessel to be dry docked
102
When testing a crane the test should not create more than a?
15% list or the immersion of the deck edge the load shall be reduced accordingly
103
overhauls of critical equipment components should not generally be required more than every?
4 or 5 years
104
Complete overhauls should not be more than
8 years
105
Graphic safe plates shall be provided and displayed at the cranes operator station as described?
1. stability, sea state limitations, graphically show safe work zones and working load limits while operating
106
How often is hydraulic fluid sampling completed?
| Semi annual
Semi annual
107
If a crane is used daily or 120 times per quarter the hydraulic oil shall be tested?
Quarterly and water shall not exceed .05%
108
What is a dynamic load test of a crane?
125% for 10 min
109
What is a static load test
150% of working load for 10 min
110
Wire rope shall be tested to ?
200% of working load limit (WLL) with certification tag attached to fitting
111
All units with cranes shall maintain _______ log
Usage log
112
Forklifts must be weight tested every ____ years
2 years
