HYDR Exam

• 1- Safty operation
• 2- Prerformance of desired function
• 3- Efficiency of operation

1- Is used to speed up the extending speed of a double acting hydraulic cylinder.

1- A system that used pressurized compressed air to eliminated sthe need for a costly hydraulic pump and tank unit.

1- Is a system that messure its own outpout and forces the output to quickly and accurately follows a comand signal. Example: power-steering system in a car

1- is to permit free flow in one direction and prevent any flow in the opposite direction.

1- Recomended is 4 ft/s in order to prevent excesively low suction pressures and resluting pump cavitation.

1- Recomended 20 ft/s in order to prevent turbulent flow and the corresponding excessive head losses and elevated fluid temperatures

1- Because coppers promotes the oxidation of petroleum oils.

• 1- Steel pipes
• 2- Steel tubing
• 3-Plastic tubing
• 4-Flexibible hoses

• 1-Provie some slack to allow for shrinkage or expansion.
• 2- Use brackets and clamps to keep hoses in place
• 3- Provide enough hose for a wide radius curve

• 1- To allows for dirt and chips to settle to the bottom
• 2- To allows entrained air to escape from oil.
• 3- To hold all the oil that might drain into the reservoir from the system
• 4- It should have adequate air space to allow for thermal expansion of the oil.

• 1- Separetor type
• 2- Non- separetor type
• 3- Pisto acumulator type

• 1- An auxiliary power source
• 2- A leakage comensator
• 3An emergency power source

• Static: are used between mating parts that do not move relative to each other.
• Dynamic: are assembled between mating parts that move relative to each other.

• 1- Leather
• 2- Buna-N
• 3- Silicone
• 4- Neoprene

• 1- Pressure gages
• 2- Flowmeters

A pressure intesifier is used to eliminate the need for a high-pressure/low-flow pump.

• 1- Clogged or dirty oil filters
• 2- Inadequate supply of oil in the reservoir
• 3- Leaking seals
• 4- Loose inlet lines
• 5- Incorrrect type of oil

• Flash point: the temperature at which the oil surface gives off sufficient vapors to ingite when a flame is passed over the surface
• Fire point: the temperature at which the oil will release sufficient vapor to support combustion continuously for five seconds when a flame is passed over the surface.
• Autogenous ignition temperature: The tempreture at which ignition occurs spontaneously.

• 1- low viscosity
• 2- incompatibility with most natural or sinthetic rubbber seals
• 3-and high cost

• Filter: is to retain by some porous medum, insoluble contaminants fro fluids
• Strainers: are constructed of a wire screen that rerely contains openings less than 100 mesh.

• 1- Air entering pump inlet
• 2- Excessive oil viscosity
• 3- Dirty inlet strainer
• 4- Excessive pump speed

• 1- Air in the fluid
• 2- Pressure relief valve set too low
• 3- Leak in hydaulic line
• 4- Defective or worn pump

• 1- Pump turning in wrong direction
• 2- Rupture hydraulic line
• 3- Low oil level in reresvoir
• 4- Broken pump shaft