Basic Systems 1 Flashcards
What are the 4 seals used in the RN
Gasket(non asbestos)
Mechanical seal
Keelering coupler
Gland packing
What 5 materials are pipes made of and systems they are used on in the RN?
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
What 3 factors affect our choice of seals?
1.Pressure of the system
2.The fluid used in the system
3. Operating temperature of the system
What 3 factors affect the choice of pipe materials?
1.Fluid used in the system
2.Operating temperature
3.Other materials in the system
What is a system?
A system is a collection of interconnecting pipes and components used to deliver a fluid to a service.
Define a open loop system.
A system that consumes the fluid inside of it e.g. fuel injection system
Define a closed loop system.
A system that reuses the fluid inside it e.g. fresh water cooling system
Name the 3 types of tanks and their uses.
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
Name the 3 gauages for showing the contents of a tank.
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)
What are strainers used for and there main advantage?
Remove large coarse particles from the fluid. The main advantage is that they are washable.
What is the purpose of a valve?
Used to control the flow of fluids and isolate systems on board.
What systems would you most likely find a gate valve.
Gate valves are used in large systems that need a valve to be open or shut like ventilation systems.
What is the use of a non return valve and 2 examples?
1.Flap valve
2.piston non return valve
To direct fluid in one direction in the system
What is a Saunders valve?
A valve with a rubber diaphragm
What is the name for a valve that moves 90 degrees and has a ball internally
Ball seated cock valve
What is the role of a Pressure relief valve?
To relief pressure of a system to a safe limit
Always after the pump in the system
What is the role of a pressure reducing valve?
Used to reduce pressure in part of a system for components or services that need lower pressures.
What is the role of a pressure control valve?
Used to Mantain the pressure of a system or part of one.
What two types of pumps are used in the RN?
1.Positive displacement pumps
2.Dynamic pumps
Dynamic pumps use bernoulies principle what is the principle?
When a fluids velocity is low the pressure is high and when it’s velocity is high the pressure is low.
How does a positive displacement pump move fluid?
The pump physically pushes the fluid from the inlet to the outlet of the pump.
What is a motor?
A competent that converts electrical energy in to mechanical motion.
How does a pressure gauge work?
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.
What gauge is used to measure vacuum and pressure and where is it normally found?
A manometer is normally used to shows the state of the a compartment the other side of air tight door.
What is a tachometer used to measure?
A tachometer is used to measure the velocity of a moving body like the main shaft of a boat.
What does a thermometer measure?
Temperature
What does a voltage meter measure?
The potential difference of a circuit.
What are the 3 types of thermometers used in the RN?
1.Pocket
2.dail face
3.fixed brass
What does a filter do?
Collects fine particals in a fluid to prevent contamination of a system
What are the two types of filters used in the RN and there advantages?
Metallic filters are reused
Absorbent filters provide a cleaner system but are disposable.
Why do we have change over cocks next to filters
To allow for filters to be changed while a system is running and to run with out filters if they are blocked
Why do we use rod gearing?
To remotely control a valve when a compartment is inaccessible.
What does a accumulator do?
Stores potential energy for later and smooth out pulsation from positive displacement pumps.
What are the two types of accumulators use in the RN?
Bag/ bladder type
Free piston type
