Fluid Power Systems - Midterm Lessons 1-6

Power

indicates the rate that work is done.

495

If 225 kg of force is exerted on a hydraulic cylinder, it is equal to ___ lb. of force.

Kilopascals (kPa)

Pressure is typically measured in psi, bars, and ___.

530.50

If a hydraulic cylinder needs to lift a bridge beam that weighs 60,000 lb and the piston in a cylinder has a surface area of 113.10 sq in., then the hydraulic system must produce system pressure of ___ psi.

Vacuum rating depends on pump design and manufacturer specifications

Most pump manufacturers recommend a vacuum rating less than or equal to ___ in. Hg.

Mercury Barometer

A __ consists of a glass tube that is completely filled with mercury and closed on one end.

Kinetic

energy is the energy of motion

Leaks, resistance to movement of mechanical devices, resistance in pipes and hoses

A common form of inefficiency in a fluid power system.

Force

is anything that changes or tends to change the state of rest or motion of a body.

Kinetic

Fluid mechanics is comprised of static energy and ___ energy

1; 1

Horsepower is a mechanical unit of measure equal to the force required to move 500 Lb, ___ ft in ___ sec

Mechanical

Energy from gears, belts, or pulleys is an example of ___ energy

Bourdon tube

The ___ pressure gauge is the most commonly used fluid power pressure gauge in the industry.

Gauge

pressure is the amount of pressure above the existing atmospheric pressure and is used to measure pressure inside a closed fluid power system.

Fluid power system efficiency

is the useful amount of output energy from a fluid power system compared to the amount input of input energy.

Green

The color ____ in a color-coded cutaway diagram indicates intake flow from the reservoir through the filters to the pump

Relief

A ___ valve protects a fluid power system from overpressure by setting a maximum operating pressure

Spring

The two types of mechanical accumulators include weight- and ___-loaded

Pump

In a hydraulic system, fluid flow is produced by a ___

Flow rate

is the amount of fluid that passes a given point in one minute

Accumulator

A(n) ___ is a vessel in which fluid is stored under pressure for future release of energy.

Capacity

is the ability to hold or contain something

Fluid flow

By controlling _ and pressure, hydrualic systems can produce a large amount of work

150; 40

For industrial applications, fluid viscosities are typically about __ SUS at ___ °C

Drop

Pressure ___ is the pressure difference between two points in a fluid power ssyteam.

Turbulent

fluid flow is present in systems where pipers, tubes, and hoses may be too small for the system.

Weighted

A ___ flow meter has high internal resistance to fluid flow.

Diaphragm gas

charged - accumulators are typically small and lightweight, with capacities up to 1 gal.

Pictorial

A(n) ___ diagram is a graphic representation of how devices interconnect within a fluid power system

Dashed

On a schematic diagram, __ lines are used to represent pilot lines.

P:T In a directional control valve, port ___ receives fluid flow from the pumo, while port ___ returns fluid flow to the reservoir.

Closed

A(n) __-center position directional control valve allows a hydraulic system to operate with more than one actuator and with each actuator operating independently of the others.

Spool

A(n) ___ is an internal component of directional control valve that is used to control fluid flow and to connect internal passages and ports.

Seven

There are __ different subplate designs.

Tandem

A(n) ___-center position directional control valve is used to hold the pisyon in a cylinder in the desired position while allowing fluid control to be directed back to the reservoir without the need ti activate relief valve.

In

line - mounting is a method that uses tubing or threaded pipes that connect directly to a directional control valve.

Actuator

A directional control valve ___ is a mechanism that is used to move the position of the spool in a directional control valve

25

Solenoids alone are not strong enough to move a directional control valve spool when fliud flow is greater than ___ gpm.

Internal arrows inside

In directional control valve schematic symbol, ___ the position boxes depict the direction of fluid flow for each spool position.

Open; tandem

A hydraulic system that does not have a variable-displacement, pressure-compensated pump typically uses a(n) ___-center or ___-center position directional control valve so that the hydraulic fluid can be returned to the reservoir

Cracking

pressure is the amount of pressure required to slightly unseat a ball or poppet and start to allow fluid flow through a check valve

Position

A(n) __ is a schematic representation of the direction in which a spool forces fluid to flow.

Pilot

pressure is initiated when the fluid pressure in a fluid power system shifts the spool into the desired position.

Pilot to open

A __ check valve allows fluid flow in one direction and restricts fluid flow in the opposite direction until it receives a pressure signal through a pilot line applied to the port against the piston

Four; four

The advantage of a three position, four-way directional control valve is that it has __ different center positions that can perform __ different operations.

Needle

A ________ valve is typically used in speed control applications.

Gate

valves are typically used for full-flow or no-flow operations and are not designed for restricting fluid flow.

Fpm; ipm Depending on the length of a rod, piston speed can be measured in _____ or _________.

2000 to 5000 psi

Gate valves are used for applications with pressures of _______ psi to ________ psi.

Meter in

A ___________ system is typically used for applications that need to extend a heavy load but retract no load.

Globe

Fluid flow must make two 90 degree turns to pass in one direction through a __________ valve.

Extension and retracion

A double-acting cylinder can be metered by controlling piston speed on ________.

Globe

A _________ valve has a disk that is raised or lowered over an orifice.

Towards

On schematic diagrams, the bypass check valve arrow points __________ the cylinder for meter-In cylinders.

Flow control valve with a check or internal check

A flow control valve and a check valve in reverse parallel with each other is also referred to as a ____________.

12,000

Ball valves can be rated as high as ________ psi.

Flow control

When piston speed is too high, it can be corrected by using a ________ valve.

Metering

is the controlling of the rate of fluid flow and how the fluid flow is being accomplished.

The cap end port or the rod end port

To control the piston speed of a double-acting cylinder, a flow control valve with a check valve is used to control the flow rate at __________ of the cylinder.

Weight of the load

The main variable that affects pressure differential in a hydraulic system is the _____________.

Heat enchangers

When heat cannot be properly dissipated, ___ must be placed in the system to help cool the hydraulic fluid by removing damaging heat from the system.

Pressure line

A ___ filter is placed before components to protect them from contaminants in hydraulic fluid.

Varnish

is a coating of a sludge-like residue that results form the breakdown of hydraulic fluid from the heat and pressure.

Back

pressure is the level of pressure on the return line of a device in a hydraulic system.

Baffle

A ___ is an artificial surface, usually a plate or wall, for deflecting, retarding, or regulating the flow of fluid.

80

Air-cooled heat exchangers work best when the ambient temperature is lower than ____ degrees F.

Breather/filler cap assembly

A ____ is used to allow air in and out of a reservoir as hydraulic fluid is pumped into the system.

Reservoir

A ___ is a holding tank for hydraulic fluid that is not in use.

200

Water-cooled heat exchangers have a max operating pressure up to ___ psi.

International Standards Organization (ISO)

Hydraulic fluid cleanliness is rated by standards developed by the ____.

Portable

A ___ filtration unit is a nonfixed filtration machine that filters fluid as it is being transferred from a storage vessel to the reservoir.

22; 500

Strainer ratings can range from ___ micrometers to ____ micrometers.

99

Absolute-rated filters with depth type elements are close to ___% efficient.

Micrometers (µm)

Contaminants in a hydraulic system are rated in ___

50 µm

Strainers typically have openings larger than ___.