lime delay valves.

lime delay valves

Pneumatic time delay valves (Figure 4.28) are used to delay opera­tions where time-based sequences are required. Figure 4.28a shows construction of a typical valve. This is similar in construction to a 3/2 way pilot-operated valve, but the space above the main valve is comparatively large and pilot air is only allowed in via a flow­ reducing needle valve. There is thus a time delay between applica­tion of pilot pressure to port Z and the valve operation, as shown by the timing diagram in Figure 4.28b. The time delay is adjusted by the needle valve setting.

The built-in check valve causes the reservoir space above the valve to vent quickly when pressure at Z is removed to give no delay off.

The valve shown in Figure 4.28 is a normally-closed delay-on valve. Many other time delay valves (delay-off, delay on/off, nor­mally-open) can be obtained. All use the basic principle of the air reservoir and needle valve.

The symbol of a normally-dosed time delay valve is shown in Figure 4.28c.

Control valves-0110

Related posts:

Applications on pneumatic:Contractors tools
THE COMPRESSOR:HEAT EXCHANGERS AND COOLERS.
BASIC DIAGRAMS AND SYSTEMS:ACCUMULATOR SAFETY CIRCUITS
Troubleshooting and material flow problems:Over feeding of pipeline
Review of pneumatic conveying systems:System types,Open systems and Positive pressure systems.
Conveying characteristics:Component pressure drop relationships
ROUBLESHOOTING HYDRAULIC SYSTEMS:FAILURE MODES OF HYDRAULIC COMPONENTS
Hydraulic fluids:General types of fluids.
Hydraulic accessories:Hydraulic accessories.
Hydraulic motors:Continuous rotation hydraulic motors
Fault-finding.
The flapper-nozzle.
Air Compressors, Air Treatment and Pressure Regulation:compressor types and Piston compressors
GAS MIXTURES AND PSYCHROMETRICS:P-v-T BEHAVIOR OF GAS MIXTURES: IDEAL AND REAL GASES
POWER AND REFRIGER A TION CYCLES:BRAYTON CYCLE: THE IDEAL CYCLE FOR GAS-TURBINE ENGINES

Leave a comment

Your email address will not be published. Required fields are marked *