Basic Systems & Diesel Engines Flashcards
What is a System?
A system is a series of interconnecting pipes and components that will deliver a substance from one point to another
Two types of System
Open Loop, Closed Loop
In which system is the working fluid consumed?
In an Open Loop system
In which system is the working fluid reused?
With a Closed Loop System.
An example of an Open Loop system
Fuel system
Example of a Closed Loop system
Fresh water cooling system
What is a Header Tank used for?
To top up a tank or system
What does a service tank contain?
A reservoir of clean fuel
Used to collect oil returning from a system and acts as a reservoir…
A Drain Tank
3 Types of Tank Gauges
- Contents gauge
- Sounding tube
- Gauge glass
Contents Gauge
Indicates remaining liquid in a tank. Dial Type.
What is a Sounding Tube?
Used to measure the depth of liquid inside a tank.
How is a Gauge glass used?
Gives a visual indication of how much liquid is left in the tank.
Dip Tape
Used to measure the liquid level left in a tank.
What is used to remove large, coarse particles from a system?
Strainers
5 common pipework materials?
Phosphor bronze, Copper, Copper Nickel, Brass, Plastic
Phosphor Bronze usage?
High Pressure Salt Water system
Copper usage?
Domestic fresh water system
Copper Nickel usage?
Lub Oil system
Brass usage?
Used for Castings. Taps, Valve bodies, Junctions and Unions.
Plastic usage?
Sewage and Pre Wet.
What do seals prevent?
Fluid leakage
Four seal types
- Gaskets (NAF, Paper, Leather, Cork, Copper, Rubber)
- Mechanical seals
- Keelering couplings
- Gland packing
One application of a Mechanical Seal?
Used for a Rotating shaft in water pump
One application of Keelering couplings?
Pipe joining for Air systems
When would you use Gland Packing?
To pack around the shaft of a pump to prevent fluid loss due to a weakened gland
How does a valve work?
It controls the flow of liquid, and is used as a means of isolating various systems.
3 main functions of a valve
- Changes to pressure
- Changes to direction
- Shuts off supply
Name me 5 types of Valves
Globe, Gate, Flap, Saunders, Pressure Relief
A valve which screws down (in the shape of a sphere)
Globe Valve
Raises and lowers, used for large ventilation pipes
Gate valve
A simple non-return valve is also known as a
Flap Valve
What is a Ball seated cock and how does it work?
Simple isolating valve. Turn the handle 90 degrees off/on.
Protects system from over-pressurisation
Pressure Relief Valve
Reduces and regulates pressure at a particular part before continuing through system.
Pressure Reducing Valve
Prevents flow reversal
Non-return valve
Which 4 main substances are transported through a pump?
Cooling, Heating, Lubrication, Fuel
What does a Pump do?
In a system it forces the movement of fluid through a system using pressure
What are the 2 main groups of Pumps?
Positive and Dynamic Displacement.
Finish the sentence: A gearwheel pump is an example of a ________ ___________ pump.
Positive Displacement
Centrifugal and Axial refers to what kind of pump?
Dynamic displacement pump
What does flow/ pressure look like in a POSITIVE DISPLACEMENT Pump?
Low flow, High pressure
What does flow/ pressure look like in a DYNAMIC DISPLACEMENT Pump?
High flow, Low pressure
Bernoulli’s Theorem (classroom door theory)
Fluid -> impeller -> velocity increase -> slows down in larger space -> pressure increase.
An Electrical Motor converts what into what?
Converts electrical energy into mechanical motion
What drives the HPSWS?
Electric motor
A Tachometer is a type of what?
System indicator
5 types of System Indicators
Pressure and Vacuum Gauges, Tachometers, Thermometers, Flow meters, Voltage meters.
Generally, all pressure and vacuum gauges are…
Bourdon tube gauges
A gauge cock allows a gauge to…
be isolated from the system
A type of system indicator whereby as pressure increases, fluid levels are forced apart. Reduction in pressure causes levels to equalise. What is it?
Manometer
A Tachometer…
Measures the speed of a moving body or substance
3 Types of Thermometer?
- Fixed brass (sheathed or cased)
- Standard Pocket/ Oblong
- Clock/ Dial face
Its plug is screwed into a threaded hole in a system pipe or machine. What is it?
A thermometer pocket
A standard or fixed brass thermometer is inserted into…?
A thermometer pocket’s recess
What do you do when a pocket is deliberately removed from a system?
Isolate and tag out the equipment.
Thermometer pockets are painted with… what?
Black and yellow warning stripes
How should you house a sheathed or cased thermometer?
In a thermometer pocket
The pocket is filled with transmission fluid, usually engine oil. Why?
To aid smoother heat energy transmission
Voltage meter
Measures the potential difference in an electrical circuit
What does a Filter do?
Removes fine particles from a system.
What are the two main types of filter?
Metallic and Absobent
Metallic filters are made from what? What are they for?
Wire wool, thin steel plates or gauze screens, and tend to filter coarser particles from a system.
Absorbent filter are made from what?
Paper, cloth, felt, yarn and other fabrics.
Fuel systems and lub oil systems require what? What type of filter is used?
A higher standard of cleanliness. They use absorbent filters
What does a Pressure Control Valve do?
It monitors outlet pressure and opens and closes as required to maintain a constant system pressure.
What is Rod Gearing?
Rod Gearing allows a valve to be shut off manually from a remote location in the event of flood or fire.
It prevents over-pressurisation in a system. What is it?
A pressure relief valve
Where is a Pressure relief valve generally found?
On the Outlet side of the Pump.
Why is a thermometer screwed into oil rather than air?
Heat travels faster through liquid, resulting in a faster, more accurate reading.
Why must we use the correct oils for their set purposes?
Each are manufactured for a certain job to avoid damage to components.
What does an Accumulator do?
Stores energy and smooths out pulsation. They can be used as a surge/pulsation dampener/ absorber.
2 purposes of an Accumulator?
It stores substance pressure and is a pulsation pressure dampener.
Most common type Accumulator?
Hydro-Pneumatic
2 Main Accumulator types?
Bag and Piston
It stores enough energy to safely start up or finish an operation in the event of pump stoppage. What is it?
An Accumulator
What is the difference between a Dynamic and Positive Displacement pump?
D Pumps maintain a steady flow of the fluid areas, whereas P Displacement pumps contain portions of fed fluid that are enclosed before being moved along.
