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:
Benefits, drawbacks and operational issues:Operating motors above base speed
Air only relationships:Air flow rate control
Energy and Efficiency:PIPE FLOW CALCULATIONS
BASIC DIAGRAMS AND SYSTEMS:FLUID POWER SYSTEMS
Health and safety:System components,Blowers ,compressors and Oil free air.
Particle degradation:Operating problems and Filtration problems
Erosive wear:Hard materials and Particle concentration
Review of pneumatic conveying systems:Mobile systems
COMPRESSORS:Dynamics
Applications of hydraulic systems:Advantages of hydraulic systems
LINES, FITTINGS, AND SEALS:FLEXIBLE HOSE
Hydraulic pumps:Pump classification.
Pressure measurement.
BASICCONCEPTS OF THE RMODYNAMICS:ENERGY AND ENVIRONMENT
FORCED CONVECTION:GENERAL CONSIDERATIONS FOR PIPE FLOW