Hydraulics

Question 1

Define a fluid

Answer 1

-A substance that will take the shape of its container
-Can be a liquid or gas

Question 2

Pressure Formula

Answer 2

Pressure = Force/Area

Question 3

What are the Advantages of Hydraulics compared to Electrics?

There are 8 advantages

Answer 3

-Reliable
-Simple and easy to understand
-Infinite Speed Range
-Easily Reversed
-Ability to withstand overload
-No spark risks
-High torque at low speeds
-1/12 the size of equivalent electric motor

Question 4

What are the Disadvantages of Hydraulics compared to Electrics?

There are 4 disadvantages

Answer 4

-Fire risk with mineral oil systems
-Noise
-Risk of Contamination
-Less Efficient (85-95%)

Question 5

What is Denso Tape used for?

Answer 5

It is used to cover hydraulic fittings on the upper deck

Question 6

What are the the hazards associated with Denso Tape?

Answer 6

It is highly flammable and gives off toxic fumes when burning

Question 7

What are Fluorocarbon Elastomers used for?

Answer 7

Used to make ‘O Rings’

Question 8

What hazards are associated with Fluorocarbon Elastomers?

Answer 8

When at exteme temperatures (300 Degrees Celcius), it can produce toxic gases such as Hydrogen Fluoride (HF)

Question 9

What PPE is required when working with Fluorocarbon Elastomers?

There are 4 types of PPE required

Answer 9

-PVC Gauntlets
-PVC Coveralls
-Rubber Boots
-Full-Face Visor

Question 10

What are the different types of Hydraulic Fluid?

Answer 10

-Petroleum Based (also known as Mineral)
-Synthetic Based

Question 11

What are the different oils in use by the RN?

Answer 11

-OX30
-OX40
-OM33
-Rust Veto

Question 12

What does O, X, M stand for when referring to oil and what does the number represent?

Answer 12

-O: Stands for Oil
-X: Stands for Synthetic
-M: Stands for Mineral
-Number: Represents Viscosity (Lower is Thinner)

Question 13

Describe OX30

Answer 13

-Red
-Synthetic oil used in hydraulic machinery on HM Submarines

Question 14

Describe OX40

Answer 14

-Green
-Synthetic oil used on hydraulic machinery on T23s, T45s and all future projects

Question 15

Describe OM33

Answer 15

-Yellow/Orange
-General-Purpose petroleum based oil used on hydraulic machinery on T22s, T42s and CVS

Question 16

Describe Rust Veto

Answer 16

-Used during upkeep periods when hydraulic oil has been removed from a system
-Used as a substitute to hydraulic fluid to prevent corrosion

Question 17

What are the requirements for a Hyrdraulic Fluid?

There are 6 requirements

Answer 17

-Transmission of Power (Main Requirement)
-Fluid must easily flow through lines
-Must be incompressible
-Lubrication
-Sealing Properties
-Cooling

Question 18

What are the most common causes of contamination in Hydraulic Oil?

There are 5 common causes

Answer 18

-Airbourne particles and moisture
-Construction Dirt
-Dirt in new fluid
-Dirt produced by wearing in new system
-Dirt from human sources

Question 19

What are the methods of reducing contamination?

There are 7 methods

Answer 19

-Good system design
-Filtration and filter management
-Operation of filter and clogging indicators
-Good working practices
-Use of a guardian filter pack
-Caps should be fitted to open pipework
-Clean working area

Question 20

What are the different types of Positive Displacement Pump?

There are 6 types

Answer 20

-Internal Gearwheel Pump
-External Gearwheel Pump
-Vane Type
-Lobe Type
-Radial Piston Type
-Axial Piston Pump

Question 21

Do we need Dynamic Displacement Pumps in a Hydraulic System?

Answer 21

No, Hydraulic Systems need high pressure pumps

Question 22

What are Axial Piston Pumps used on?

Answer 22

-Stabiliser Systems
-CPP Systems
-Steering Systems

Question 23

What is the purpose of an Actuator?

Answer 23

To convert Hydraulic Energy into Mechanical Motion

Question 24

What are the different types of Actuators?

Answer 24

-Linear
-Rotary

Question 25

What are the different types of Linear Actuators?

Answer 25

-Single
-Double Acting

Question 26

What is an Accumulator?

Answer 26

A device in which potential energy is held under pressure

Question 27

What are Accumulators used for?

Answer 27

Storing energy and smoothing out pulsations