fluid power

The purpose of a relief valve in a hydraulic circuit is to _____.

All are correct

Which of the following is used to calculate the pressure of a fluid?

Force/Area

The loss of pressure through components such as valves, fittings, and piping is called _____, or differential pressure.

head loss

What is the relationship between pressure and volume when gas temperature is held constant?

Inversely proportional

What does a higher viscosity index mean?

Less affected by temperature change

Which of the following is an example of external fluid contamination?

Airborne contaminants

How are psia and psig related?

psia = psig + 14.7

According to Pascal's law, what occurs when there is an increase in pressure at one point in a system?

Pressure increases throughout the system.

FRL in a pneumatic unit stands for _____, _____, and _____.

filter, regulator, lubricator

What determines whether a cylinder extends or retracts in an actuator?

The port to which pressure is applied

Flow is caused by a difference in air compression.

False

Pressure, volume, and temperature can be calculated at an instantaneous point but also across an event.

True

Entrained particulates and moisture both affect the cleanliness of a pneumatic system.

True

How is the length of a hydraulic hose assembly measured?

Sealing face to sealing face

Hydraulic systems are typically used for applications requiring higher speeds and lower pressures.

False

The symbol for a hydraulic pump uses an empty triangle to show flow.

False

The symbol for a bidirectional hydraulic motor uses two triangles within the circle.

True

A blocked center position on a three-way valve will hold a cylinder in position.

True

Viscosity is a measurement of a fluid's resistance to flow.

True

The forming and collapse of air or gases inside a pump is a form of _____.

cavitation

Silting affects valve operation by causing _____.

All are correct.

A _____ is the open end of a passage that fluid passes through.

port

In a hydraulic system where the loading of the system changes and different flow rates are needed, a _____ pump circuit is ideal.

hi-lo

Cylinder _____ can help reduce noise and wear on the cylinder.

cushions

Hydraulic _____, also called linear actuators, transfer the energy from a fluid into linear motion and mechanical force.

cylinders

_____ will increase the temperature of a running hydraulic system.

All are correct.

What is the typical temperature limit for hydraulic oil on industrial hydraulic systems?

180°F

As pressure drop increases across a valve, flow through the valve will _____.

increase

In a remotely piloted relief valve, how does the remote signal affect relief operation?

It increases the pressure setpoint.

The heat dissipated by the reservoir depends on the ____.

All are correct.

Sacrificial anodes work by ____.

using zinc that corrodes before the other metals

In a vane pump, ____.

All are correct.

The volume displaced by a piston pump is determined by the ____.

pump rpm and swash plate angle

The three main types of valves are ____

pressure control, flow control, and directional control

The purpose of an air breather on a hydraulic reservoir is to ____.

prevent a vacuum from forming due to changes in temperature

Silting is the accumulation of fine particles that can block a spool's actuation.

True

One of the purposes of the reservoir is to allow particulates to settle.

True

A pressure-compensated vane pump uses the rotary motion of gears to directly move fluid through the unit.

False

As a hydraulic fluid's temperature changes, the viscosity of the fluid also changes.

True

In a sequential system, all sequence valves have tags that show where pressure drops occur.

False

Using a stop tube on long-stroke or horizontally mounted cylinders _____.

reduces bearing load

The purpose of a cylinder is to convert energy into _____.

linear motion

The purpose of an air receiver is to _____.

All are correct.

How is receiver size affected if CFM is higher?

Size is increased.

A purpose of primary air treatment is _____.

removal of particulates

The purpose of an intercooler in a two-stage compressor is to _____.

increase the efficiency of the second stage

All moisture removed from a pneumatic system should be directed to what component?

Oil/water separator

A _____ allows free, unrestricted flow in one direction while regulating flow in the opposite direction with the use of a needle valve.

directional flow regulator

Desiccant turns ______ when expended.

green

In a heatless regenerative desiccant system, the _____.

off-line stack is regenerated using dry air from the online stack

In-line desiccant dryers can be regenerated by baking the media to _____.

275°F

With an FRL unit, as downstream pressure drops, the _____ opens to allow flow.

regulator

A single-stage piston air compressor is efficient up to _____.

130 psig

Unloading is _____.

removing the load from the mechanical side of the compressor while starting up

The three main types of pneumatic distribution systems are _____.

loop, branched, and parallel

A 5/2 pneumatic valve would be a valve with _____.

5 ports and 2 positions

Two-stage reciprocating compressors provide lower pressures than single-stage compressors.

False

Rotary screw compressors are especially cost effective in smaller systems.

False

Secondary air treatment involves moisture separation, pressure regulation, and lubrication.

True

Valves, fittings, and piping in pneumatic systems are much heavier and physically larger than hydraulic versions due to the system using much higher pressures with noncompressible fluid.

False

Valves are _____ elements that sense flow and pressure to provide the desired logic function.

logic

In terms of a spool valve, what is deadband?

Overlap of spool to a fluid cavity

What must occur in order for a sequence to advance to the next step?

All previous steps have taken place

An AND function ensures _____.

two things both happen

The advantage of a manifold is that it _____.

All are correct.

In slip-in valves, what is the purpose of a poppet?

It seals and unseals a port with movement.

What is the purpose of the orifice in the cover assembly of a slip-in valve?

It adjusts valve response time.

Miniature valves typically _____.

All are correct.

A PLC can be summarized by _____.

programmed logic elements

What is the role of a proportional valve?

Control spool position based on a process input

Taking care of silting in a monoblock requires which of the following?

All are correct.

The main difference between screw-in and slip-in cartridge valves is that _____.

All are correct.

_____ is another name for sensitivity.

Gain

In a PLC-controlled pneumatic system, logic _____.

is achieved by programming within the PLC

In a YES function, _____.

a low-pressure input causes a high-pressure output

Proportional valves are highly accurate and are held to tighter tolerances than servo valves.

False

Using a manifold reduces production time.

False

Using a manifold reduces the possibility of leaks.

True

All internal passageways of manifolds are machined.

True

A servo valve's internal filters will eventually clog and affect valve response.

True