chapter 60-120_part 1

Question 1

device used for
converting mechanical energy into hydraulic energy

Answer 1

positive displacement hydraulic pump

Question 2

driven by a
prime mover such as an electric motor

Answer 2

positive displacement hydraulic pump

Question 3

two functions of the positive displacement hydraulic pump

Answer 3

creates a partial vacuum
mechanical action of the pump

Question 4

less expensive but limited to
pressures below 140 bar. It is noisy in operation than
either vane or piston pumps

Answer 4

.gear pump

Question 5

ess expensive but limited to
pressures below 140 bar. It is noisy in operation than
either vane or piston pumps.

Answer 5

gerotor pumps

Question 6

have both elements
externally driven and neither element has any contact with the
other. For this reason, they are quieter when compared to other
types of gear pumps

Answer 6

lobe pumps

Question 7

have both elements
externally driven and neither element has any contact with the
other. For this reason, they are quieter when compared to other
types of gear pumps

Answer 7

Screw Pumps

Question 8

used to regulate and control the
flow and pressure in any assigned manner are called
control valves or simply valves.

Answer 8

Control Valves

Question 9

three types
of valves employed in hydraulic
systems:

Answer 9

1.Directional control valves
2. Flow control valves
3.Pressure control valves

Question 10

used to control
the distribution of energy in a fluid power system. They
provide the direction to the fluid and allow the flow in a
particular direction. These valves are used to control
the start, stop and change in direction of the fluid
flow

Answer 10

directional control valves

Question 11

classification of control valves based on Type of construction:

Answer 11

*Poppet valves
*Spool valves

Question 12

classification of control valves based on actuating mechanism

Answer 12

*Manual actuation
*Mechanical
actuation
*Solenoid actuation
*Hydraulic actuation
*Pneumatic
actuation
*Indirect actuation

Question 13

check valve

Answer 13

unidirectional valves
and permit the free flow
in one direction only.

Question 14

unidirectional valves
and permit the free flow
in one direction only.

Answer 14

spool valve

Question 15

spool is operated manually. Manual
actuators are hand lever, push button and pedals etc.

Answer 15

Manual actuation

Question 16

DCV spool can be operated by using mechanical
elements such as roller and cam, roller and plunger and
rack and pinion etc. In these arrangements, the spool end is
of roller or a pinion gear type.

Answer 16

mechanical actuation

Question 17

also known as an electric actuator

Answer 17

solenoid actuation

Question 18

usually known as
pilot-actuated valve

Answer 18

Hydraulic actuation

Question 19

DCV can also be operated by applying
compressed air against a piston at either
end of the valve spool.

Answer 19

Pneumatic actuation

Question 20

can regulate the flow or pressure of the fluid.

Answer 20

Flow Control Valves

Question 21

has a plug which can be
adjusted in vertical direction by setting flow adjustment screw.
The adjustment of plug alters the orifice size between plug
and valve seat.

Answer 21

plug or glove valve

Question 22

consists of a
disc which can rotate inside the pipe. The angle of disc
determines the restriction. Butterfly valve can be made to any
size and is widely used to control the flow of gas.

Answer 22

butterfly valve

Question 23

This type
of flow control valve uses a ball rotated inside a
machined seat.

Answer 23

ball valve

Question 24

used to protect the hydraulic components from
excessive pressure. This is one of the most
important components of a hydraulic system and
is essentially required for safe operation of the
system.

Answer 24

Pressure relief valves

Question 25

consists of a control chamber
with an adjustable spring which pushes the spool
down.

Answer 25

Unloading Valve

Question 26

divert flow in a predetermined
sequence. It is used to operate the cycle of
a machine automatically. A sequence
valve may be of direct- pilot or remote-pilot
operated type.

Answer 26

Sequence Valve

Question 27

can be used as breaking
valves for decelerating heavy loads. These valves are used
in vertical presses, lift trucks, loaders and other machine
tools where position or hold suspended loads are important.

Answer 27

Counterbalance Valve

Question 28

These valves are used to limit the outlet pressure. Generally,
they are used for the operation of branch circuits where the
pressure may vary from the main hydraulic pressure lines.

Answer 28

Pressure Reducing Valve

Question 29

Letter/s used to represent the pressure Ports

Answer 29

P

Question 30

Letter/s used to represent the working ports

Answer 30

A, B

Question 31

Letter/s used to represent the exhaust ports

Answer 31

R, S

Question 32

Letter/s used to represent the pilot ports

Answer 32

Z, Y