Flow Control Valve

No. 1/51©FESTO DIDACTIC – Training & Consulting PRESENTATION

Sam Mahmoudi Sam Mahmoudi Deputy manager Didactic department Festo IranDeputy manager Didactic department Festo [email protected]

Festo Didactic Welcomes YouFesto Didactic Welcomes YouFlow control valve

mailto:[email protected]


Flow control valves are used to reduce the speed of a cylinder or ther.p.m. of a motor. Since both values are dependent on the flow rate,this must be reduced. However, fixed displacement pumps supply auniform flow rate. Reduction in the rate of flow supplied to the driveelement is achieved according to the following principle:A reduction in the flow cross-section in the flow control valve causesan increase in pressure ahead of this. This pressure causes the pressurerelief valve to open and, consequently, results in a division of theflow rate. This division of the flow rate causes the flow volume requiredfor the r.p.m. or speed to flow to the power component and the excessdelivery to be discharged via the pressure relief valve. This results ina considerable energy loss.In order to save energy, adjustable pumps can be used. In this case,the increase in pressure acts on the adjustable pump device.On the basis of their controlling or regulating function, flow controlvalves are classified as either:- flow control valves or- flow regulating valves.

procedure

procedure

throttle orifice

Drawing press

A drawing press is used to shape metal workpieces. Following

modificationof the hydraulic system, the

workpieces are no longer dimensionally

accurate. The reason for this may be that the required press

pressure is not being reached. Use a special test set-up to measurethe hydraulic resistance of the

components used.

throttle

orifice

Pressure Hammer :

- Weight- space of installation- number of components- flexible in design & function- accuracy- repeatability- service – life- safety- reliability- product quality- maintenance – free- easy to install- easy to start – up- diagnosis- production time- shock elimination- high efficiency- low noise- high life of static & dynamic seals- near to actuator- degree of automation

No. 1/18©FESTO DIDACTIC – Training & Consulting presentation


Restrictors and orifice valves

Restrictors and orifice valves represent a flow resistance. This resistanceis dependent on the flow cross-section and its geometric formand on the viscosity of the liquid. When hydraulic fluid is passedthrough the flow resistor, there is a fall in pressure as a result of frictionand of an increase in the flow velocity. The part of the pressure dropcaused by friction can be considerably reduced by changing the orificeshape. In order to obtain the required resistance using an orifice, turbulencemust be achieved by increasing the flow velocity (smallercross-section than that of a corresponding restrictor). In this way, theresistance of the orifice is determined by the turbulence and becomesindependent of viscosity. For this reason, orifice valves are used incases where independence from temperature and, therefore, fromviscosity is required, e.g. in flow gauges.


Cavitation and micro diesel



flow Control

Dependent on load

Independent of load

Meter in

Meter off

Bleed off

Meter in

Meter off


One-way flow control valveFlow control valve with free flow check valve



METER_IN

Evaluation

P1P2Q1Q2PBP, …

Tractive force


METER_OUT

Evaluation

P1P2Q1Q2PBP, …



2- way flow regulator valveFlow control valve with pressure compensation ( RESTRICTOR TYPE )


2- way flow regulator valveFlow control valve with pressure compensation ( RESTRICTOR TYPE )


METER_IN

Evaluation

P1P2Q1Q2PBP, …

Tractive force


METER_OUT

Evaluation

P1P2Q1Q2PBP, …





Variable tractive force


COUNTER BALANCE VALVE(COUNTER PRESSURE VALVE)


COUNTER BALANCE VALVE(COUNTER PRESSURE VALVE)


Setting procedure


Setting procedure


Setting procedure



Embossing Machine

A special machine is used to emboss graphic symbols on metal foil.The foil is fed through the embossing machine with an adjustablecycle time. The downward motion of the stamp must be capable ofbeing varied in accordance with the feed speed. The return motionmust always be executed as a rapid traverse.A one-way flow control valve is used to control the speed of thestamp, while a pressure relief valve is used to prevent the weight ofthe stamp from pulling the piston rod out of the cylinder. A 4/2-wayvalve is used to switch between upwards and downwards motion.


Embossing Machine


Ferry loading ramp

The loading ramp of a car ferry must be capable of being set todifferent heights. The ramp is raised and lowered by a hydrauliccylinder. This motion must be carried out smoothly and at a constantspeed. A flow control valve is to be used to adjust the speed. Thismust be installed in such a way as to prevent excessive pressuresfrom developing within the system.


Ferry loading ramp


Skip handling

The loading and unloading of skips from a skip transporter is carriedout using two double-acting cylinders. Each cylinder is subject tovarying loads – tractive load during unloading and compressive loadduring loading. The skip should be raised and lowered at a slow constantspeed. Each cylinder must therefore be hydraulically clampedon both sides.


Skip handling


Flow Control Valve

Documents