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:

Benefits, drawbacks and operational issues:Resonance and rotor dynamics
Vacuum and Low Pressure:Vacuum pumps
Energy and Efficiency:Output energy available
Air flow rate evaluation:The influence of temperature and Conveyed material influences.
High pressure:Twin blow tank systems
THE COMPRESSOR:COMPRESSOR PERFORMANCE.
Low pressure and vacuum:Suction nozzles and Feed rate control.
Control components in a hydraulic system:Flovvrneters.
Conveying capability:Low pressure conveying – Part II
Hydraulic cylinders:Construction
Proportional Valves.
Hydraulic and Pneumatic Accessories:Hydraulic and Pneumatic fuses
PROPERTIES OF PURE SUBSTANCES:COMPRESSIBILITY FACTOR—A MEASURE OF DEVIATION FROM IDEAL-GAS...
SUMMARY OF THE FIRST LAW OF THERMODYNAMICS
POWER AND REFRIGER A TION CYCLES:REFRIGERATORS AND HEAT PUMPS

Leave a comment

Your email address will not be published.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