hydraulics 4

Question 1

what are the advantages of hydraulics?(9)

Answer 1

high force multiplication
reliable
simplicity
infinite speed range
easily reversed
ability to withstand overload
no spark risk
high torque at low speeds
smaller

Question 2

what is a actuator?

Answer 2

any component that converts hydraulics pressure into movement.

Question 3

what is a fluid?

Answer 3

a substance that will take shape of its container
capable of transmitting power
liquid or gas

Question 4

what is the formula for pressure?

Answer 4

pressure = force / area

Question 5

how do you increase the output force?

Answer 5

make the output piston larger.

Question 6

what are disadvantages of hydraulics compared to a electrical equivalent ?(5)

Answer 6

fire risk on mineral oil systems
noisy
less efficient (85-95%)
contamination
limited amount of fluid

Question 7

what is Denso tape and its hazards?

Answer 7

tape used to cover hydraulic fittings and pipework to slow down corrosion.

Will release toxic fumes when burned.

Question 8

what is fluorocarbon elastomers and the hazards

Answer 8

the rubber used for o rings

Question 9

what is the hazzard with denso tape

Answer 9

highly flammable and highly toxic when burning

Question 10

what PPE is need for fluorocarbon elastomers after a fire?(4)

Answer 10

PVC gauntlets
rubber boots
PVC coveralls
full face visor

Question 11

what are the hazards with fluorocarbon elastomers (3)

Answer 11

melts at 300 degrees C
creates hydrogen fluoride(white powder)
if mixed with water makes hydrogen fluoride acid

Question 12

what are the precautions when working with hydraulics oils?(8)

Answer 12

oils cause skin irritation
change oil soaked clothes immediately
bring any irritation to medical staff
ALWAYS CONSULT THE HAZARD DATA SHEET
mineral oil poses fire danger
flexi hoses are to be in date and tested
gauge glass valves are to be shut except when in use
take suitable precautions before welding or burning

Question 13

what are the two types of hydraulic oil?

Answer 13

petroleum based
synthetic based

Question 14

what is the benefit of mineral based oil

Answer 14

inexpensive
has a wide variety of functions

Question 15

what is synthetic oil

Answer 15

oils for specific purposes done by adding additives to prevent undesirable properties.

Question 16

why do we never mix synthetic and mineral oil?

Answer 16

as under pressure it will jellify.

Question 17

what does the O,X,M and number mean in oil names?

Answer 17

O = Oil
X = synthetic
M = mineral
Number = the viscosity (lower is thinner)

Question 18

what is OX30?

Answer 18

A synthetic oil used in hydraulic systems on board submarines and is RED in colour.

Question 19

what is OM33?

Answer 19

A mineral oil used in hydraulic systems on old surface fleet and is YELLOW/ORANGE in colour.

Question 20

What is OX40?

Answer 20

A synthetic oil used on newer ships and is GREEN in colour.

Question 21

what is rust veto?

Answer 21

substitute for your oil when in refit

Question 22

What is the requirements of hydraulic fluids?(6)

Answer 22

must flow through lines easily
must be as incompressible as possible so action is instant.
transmit force

secondary requirements
lubricate moving parts
seal some parts of the system
remove heat from the system

Question 23

why do we use rust veto

Answer 23

to stop corrosion in your systems when your ship is in for a long refit and the oil is removed

Question 24

what additives do we add to hydraulic oil?(5)

Answer 24

anti foam(allows air to escape)
anti oxidants(slows the rate it oxidises which will make it thicker)
anti corrosion
Demulsibility (separates water from the oil)
pour point depressant (helps it to flow at lower temps)

Question 25

what does demulsibilty do in our oil

Answer 25

serparates water from the oil

Question 26

what does pour point depressant do in our oil

Answer 26

helps it flow at low tempretures

Question 27

what are the most common contaminates of oil?(5)

Answer 27

airborne particles
construction dirt
dirt in new fluid
dirt produced by wearing new systems
dirt from human sources

Question 28

how do we reduce oil contamination?(6)

Answer 28

good system designs
good filter maintenance
good working practices
guardian filter packs (portable filter for new bulk fluid embarking)
cap off open pipework
keep a clean working area

Question 29

what are the two types of hydraulic systems?

Answer 29

ring main system(used for secondary systems)
standalone power packs(used for operational equipment)

Question 30

what is the drain line used for on a hydraulic system (3)

Answer 30

lubrication
cooling
creates a seal

Question 31

label the diagram

Answer 31

Question 32

6 types of positive displacement pumps

Answer 32

external gear type pumps
internal gear type pump
vane pump
lobe pumps
piston pump
radia piston pump

Question 33

label the pump

Answer 33

Question 34

label the pump

Answer 34

Question 35

label this pump

Answer 35

Question 36

label this pump

Answer 36

Question 37

label this pump

Answer 37

Question 38

what is the plate on an axial piston pump know as?

Answer 38

swash plate.

Question 39

what are the two types of axial piston pumps?

Answer 39

fixed (swash plate does not move. set direction and flow rate)
variable(swash plate moves. variable direction and flow rate depending on swash plate angle)

Question 40

what systems normally use variable axial pumps?(3)

Answer 40

Controllable Pitch Propeller
Stabilizers
steering

Question 41

what types of actuators exists?(2)

Answer 41

rotary
linear:
single acting
double acting

Question 42

what do actuators do?

Answer 42

convert hydraulic energy into mechanical movement