Basic Systems 1

Question 1

What are the 4 seals used in the RN

Answer 1

Gasket(non asbestos)
Mechanical seal
Keelering coupler
Gland packing

Question 2

What 5 materials are pipes made of and systems they are used on in the RN?

Answer 2

Copper used for domestic fresh water
Plastic used for sewage and prewet
Phosphure bronze used for High Pressure Salt Water systems
Copper nickel used on the lube oil systems
Brass used for valves,unions and other cast components

Question 3

What 3 factors affect our choice of seals?

Answer 3

1.Pressure of the system
2.The fluid used in the system
3. Operating temperature of the system

Question 4

What 3 factors affect the choice of pipe materials?

Answer 4

1.Fluid used in the system
2.Operating temperature
3.Other materials in the system

Question 5

What is a system?

Answer 5

A system is a collection of interconnecting pipes and components used to deliver a fluid to a service.

Question 6

Define a open loop system.

Answer 6

A system that consumes the fluid inside of it e.g. fuel injection system

Question 7

Define a closed loop system.

Answer 7

A system that reuses the fluid inside it e.g. fresh water cooling system

Question 8

Name the 3 types of tanks and their uses.

Answer 8

Header tank: used to top up a system and prevent vacums happening in the system
Service tank: a clean tank for water free fuel
Drain tank: collects oil returning from a system to be reused or drained

Question 9

Name the 3 gauages for showing the contents of a tank.

Answer 9

1.Contents gauge (dial face to show content)
2.Sounding tube and conversion chart
3.Gauge glass (fitted with a press valve to prevent spillage of the tank if the glass is broken)

Question 10

What are strainers used for and there main advantage?

Answer 10

Remove large coarse particles from the fluid. The main advantage is that they are washable.

Question 11

What is the purpose of a valve?

Answer 11

Used to control the flow of fluids and isolate systems on board.

Question 12

What systems would you most likely find a gate valve.

Answer 12

Gate valves are used in large systems that need a valve to be open or shut like ventilation systems.

Question 13

What is the use of a non return valve and 2 examples?

Answer 13

1.Flap valve
2.piston non return valve

To direct fluid in one direction in the system

Question 14

What is a Saunders valve?

Answer 14

A valve with a rubber diaphragm

Question 15

What is the name for a valve that moves 90 degrees and has a ball internally

Answer 15

Ball seated cock valve

Question 16

What is the role of a Pressure relief valve?

Answer 16

To relief pressure of a system to a safe limit
Always after the pump in the system

Question 17

What is the role of a pressure reducing valve?

Answer 17

Used to reduce pressure in part of a system for components or services that need lower pressures.

Question 18

What is the role of a pressure control valve?

Answer 18

Used to Mantain the pressure of a system or part of one.

Question 19

What two types of pumps are used in the RN?

Answer 19

1.Positive displacement pumps
2.Dynamic pumps

Question 20

Dynamic pumps use bernoulies principle what is the principle?

Answer 20

When a fluids velocity is low the pressure is high and when it’s velocity is high the pressure is low.

Question 21

How does a positive displacement pump move fluid?

Answer 21

The pump physically pushes the fluid from the inlet to the outlet of the pump.

Question 22

What is a motor?

Answer 22

A competent that converts electrical energy in to mechanical motion.

Question 23

How does a pressure gauge work?

Answer 23

As pressure is built in the bourdon tube it extends moving gears attached to it to turn a arrow that lines up with a dial.

Question 24

What gauge is used to measure vacuum and pressure and where is it normally found?

Answer 24

A manometer is normally used to shows the state of the a compartment the other side of air tight door.

Question 25

What is a tachometer used to measure?

Answer 25

A tachometer is used to measure the velocity of a moving body like the main shaft of a boat.

Question 26

What does a thermometer measure?

Answer 26

Temperature

Question 27

What does a voltage meter measure?

Answer 27

The potential difference of a circuit.

Question 28

What are the 3 types of thermometers used in the RN?

Answer 28

1.Pocket
2.dail face
3.fixed brass

Question 29

What does a filter do?

Answer 29

Collects fine particals in a fluid to prevent contamination of a system

Question 30

What are the two types of filters used in the RN and there advantages?

Answer 30

Metallic filters are reused
Absorbent filters provide a cleaner system but are disposable.

Question 31

Why do we have change over cocks next to filters

Answer 31

To allow for filters to be changed while a system is running and to run with out filters if they are blocked

Question 32

Why do we use rod gearing?

Answer 32

To remotely control a valve when a compartment is inaccessible.

Question 33

What does a accumulator do?

Answer 33

Stores potential energy for later and smooth out pulsation from positive displacement pumps.

Question 34

What are the two types of accumulators use in the RN?

Answer 34

Bag/ bladder type
Free piston type