Chapter 7 - Flow Control Concepts and Definitions in Physics

A ________ valve is typically used in speed control applications.

Needle

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

Gate

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

fpm; ipm

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

2000-5000 psi

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

meter-In

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

globe

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

All of the above / Extending and restricting

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

globe

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

towards

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

flow control valve with a check or internal check

Ball valves can be rated as high as ________ psi.

12,000

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

None of the above

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

Metering

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.

the cap-end port or the rod-end port

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

weight of the load

A meter-In system is used to control piston speed of a single-acting cylinder during __________.

extension

______________ systems are typically used in double-acting cylinders when an abrupt change from high pressure to low pressure may occur.

Meter-out

Fluid flow is usually metered in only one direction by using a flow control valve with a ______________.

check valve

Fluid flow takes a ________ turn through a flow control valve to create a pressure differential.

90 degree

A _________ cylinder uses fluid flow for extensions and a spring, gravity, or other mechanical means for retraction.

single-acting

A(n) __________ valve compensates for changes in hydraulic fluid temperature and pressure.

temperature and pressure compensated flow control

A ___________ cylinder has fluid pressure flow alternately on both sides of the cylinder to extend and retract the piston.

double-acting

Most flow control valves used in hydraulic systems are __________ valves.

needle

When calculating the piston speed of a cylinder with no load, the 2 variables that must be considered are _______ and ________.

flow rate; piston face area.

_________ is controlling of the rate of fluid flow.

Metering

A variable orifice in a flow control valve is also referred to as ________.

compensated flow control.

When a load on a double-acting cylinder remains constant, a meter-_________ systems has the most accurate speed control.

in

Some types of _____ valves have color-coded valve stems.

needle

____________ flow control valves operate by maintaining a constant pressure differential across the valve's orifice.

Pressure-compensated

A _______ valve is a two-position valve with an integral gate between the two seats of the orifice.

gate

When using meter-In flow control to control the speed of the piston during extension only, a flow control valve with check valve is placed between the DCV and the ______-end port of the cylinder.

cap

__________ is a type of flow control where a needle valve (no check) controls the flow of fluid to the reservoir in a parallel leg of the system to control the speed of an actuator.

Bleed-off

The most common method of compensating for changes in hydraulic fluid temperature is to use a flow control valve that has a(n) ________ through the path of fluid flow.

pointed bimetallic stem

The primary function of a(n) _______ valve is to control the rate of fluid flow.

flow control

If the load on a hydraulic cylinder is reduced, piston speed ________.

increases

T/F: Meter-In systems are used only for controlling piston speed.

F

T/F: Bleed-off systems are used when more flow control accuracy and less system efficiency are required.

F

T/F: To control the piston speed of a double-acting cylinder during retraction by using meter-In, a flow control valve is attached to the rod end of the cylinder.

T

T/F: Gate valves have ports that are the same size as the means of transmission.

T

T/F: Piston speed is not affected by the amount that an orifice in a flow control valve is open to allow fluid flow.

F

T/F: The metering of a double-acting and single-acting cylinder is performed differently.

T

T/F: Meter-In systems are more commonly used than meter-out systems in double-acting cylinders.

F

T/F: A variable orifice is a valve.

F

T/F: The difference between a meter-In system and a meter-out system on a double-acting cylinder is that the flow control valves must be reversed.

T

T/F: Gate valves can allow fluid flow in both directions, unless otherwise marked.

T

T/F: The greater the pressure differential across a needle valve, the less the flow rate through the valve.

F

T/F: A ball valve has a ball with an orifice through its center to allow fluid flow.

T

T/F: A bleed-off system uses a flow control valve without a check valve.

T

T/F: Gate valves are designed for low-pressure service, typically no higher than 150 psi.

F

T/F: Either port of a double-acting cylinder can function as an input or an output, depending on whether the cylinder is extending or retracting.

T

T/F: Meter-out is used in applications that require high accuracy unless pressure conditions do not allow such use.

F

T/F: Needle valves can have built-In check valves for applications that require fluid flow in the opposite direction of the needle valve's metered flow.

T

T/F: Bleed-off systems used for flow control have less efficiency than meter-In or meter-out systems.

F

T/F: Fluid flow can only be metered while using double-acting cylinder.

F

T/F: Bleed-off meters fluid flow to and from a cylinder by returning (bleeding-off) some of the hydraulic fluid to the reservoir.

T

T/F: An orifice is smaller than the inside diameter of a pipe, hose, tube, or internal passage.

T

T/F: All gate valves have a nonrising-stem design.

F

T/F: If the load on a cylinder increases, the pressure differential across the flow control valve decreases, and fluid flow out of the flow control valve also decreases.

T

T/F: Needle valves have an infinite number of positions for flow control.

T

T/F: A bleed-off system uses a flow control valve with a check valve as a bypass.

F