Sequence valves
The sequence valve is a close relative of the pressure relief valve and is used where a set of operations are to be controlled in a pres sure related sequence. Figure 4.27 shows a typical example where a workpiece is pushed into position by cylinder 1 and clamped by cylinder 2.
Sequence valve V2 is connected to the extend line of cylinder 1. When this cylinder is moving the workpiece, the line pressure is low, but rises once the workpiece hits the end stop. The sequence valve opens once its inlet pressure rises above a preset level.
Cylinder 2 then operates to clamp the workpiece. A check valve across V2 allows both cylinders to retract together.
Related posts:
Control principles for variable speed pumping:Speed variation for positive displacement pumps
Compressed Air Transmission and Treatment:Tool lubrication
High pressure:Rotary valves,Blow tanks,Basic blow tank types and Top and bottom discharge.
THE COMPRESSOR:COMPRESSOR INSTALLATION.
Erosive wear:Data sources and Issues considered.
Coarse material:Procedure and Operating point.
FORCES IN LIQUIDS:STATIC AND DYNAMIC FACTORS.
Applications of hydraulic systems:Advantages of hydraulic systems
Maintenance and troubleshooting:Preventive maintenance
Maintenance and troubleshooting:Prevention of premature hydraulic component failure
Control components in a hydraulic system:Open and closed center hydraulic circuits.
ENERGY TRANSFER BY HEAT,WORK,AND MASS:FLOW WORK AND THE ENERGY OF A FLOWING FLUID
THE FIRST LAW OF THERMODYNAMICS:ENERGY BALANCE FOR CLOSED SYSTEMS
SUMMARY OF ENTROPY
RADIATION HEAT TRANSFER:VIEW FACTOR RELATIONS