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:
Case studies:Variable speed drives on heating, ventilating, air conditioning {HVAC) system pumps.
System and process requirements:Supply and demand controlled systems
High pressure:Problems with moisture
Air movers:Specification of air movers
Particle degradation:Particle breakage
Troubleshooting and material flow problems:With change of distance.
Low pressure and vacuum:Pressure drop and Maintenance
Conveying capability:Low pressure conveying – Part II
HYDRAULIC FLUIDS:Density and Compressibility
Hydraulic fluid:Applications of hydraulic systems
Sequencing applications.
Process Control Pneumatics:Pneumatic controllers
ENTROPY:WHAT IS ENTROPY?
RANKINE CYCLE: THE IDEAL CYCLE FOR VAPOR POWER CYCLES
HEAT EXCHANGERS:SELECTION OF HEAT EXCHANGERS