POWER STORAGE DETAILS Block diagram: The voltage generated by the source (generator) is not of pure dc. This has to be rectified before storage. A diode rectifier then provides a full-wave rectified voltage that is initially filtered by a simple capacitor filter to produce a dc voltage. Block diagram (Power supply) Working principle: The Full Wave Bridge Rectifier Full Wave Bridge Rectifier uses four individual rectifying diodes connected in a closed-loop "bridge" configuration to produce the desired output. The main advantage of this a bridge circuit is that it does not require a special center-tapped transformer, thereby reducing its size and cost. The single secondary winding is connected to one side of the diode bridge network and the load to the other side as shown below. The Diode Bridge Rectifier The four diodes labeled D1 to D4 are arranged in “series pairs” with only two diodes conducting current during each
These water valves are operated by handles.
A valve is a device that regulates the flow of a fluid (gases, liquids,
fluidized solids, or slurries) by opening closing or partially obstructing
various passageways. Valves are Technically pipe fittings. But are usually
discussed as a rate category In an open valves Fluid flows in a direction from
higher pressure to lower pressure. Valves are also found in the Human body. For
example, several heart valves control the flow of blood in the
chambers of the heart and maintain the correct pumping action.
Valves are used in a variety of contexts, including
industrial, military, commercial Residential, and transportation. The
industries in which the majority of valves are used are oil and gas. Power generation,
mining, water reticulation. Sewerage and Chemical Manufacturing.Plumbing
valves, such as taps for hot and cold tap water are the most Noticeable types
of valves. Other valves encountered daily include gas control valves
on cookers, small valves fitted to washing machines and dishwashers, and safety
devices fitted to hot water systems.
Valves may be operated manually, either by a hand wheel,
lever or pedal. Valves may also be automatic. Driven by changes in pressure,
temperature, or flow. These changes may act upon a diaphragm or a piston which
in turn activates the valve, examples of this type of valve found commonly are
safety valves fitted to hot water systems or boilers.
More complex control systems using valves requiring
automatic control based on an External input (i.c regulating flow through a pipe
to a changing set, point requires an actuator.
An actuator will stroke the valve depending on its input and
set-up, allowing the valve to Positioned accurately and allowing control over a
a variety of requirements. Valves are Also found in the Otto cycle (internal
combustion) engines are driven by a camshaft, tappet or Pash rods where they play a
a major role in engine cycle control.
APPLICATIONS:
- Valves vary widely in form and application Sizes typically range from 0.1 mm 60 cm (2 ft). Special valves can have a diameter exceeding 5 meters.
- Valve cost ranges from simple inexpensive disposable valves to specialized valves Cost thousands of US dollars per inch of diameter.
- Disposable valves maybe found inside common household items including mini-pump dispensers and aerosol cans
TYPES:
The inside of an extremely large butterfly valve
Valves are quite diverse and may be classified into a number
of basic types. Valves may So be classified by how they are actuated:
- Hydraulic
- Pneumatic
- Manual
- Solenoid
- Motor
BASIC TYPES:
valves can be categorized into the following basic types:
DUPLEX BALL VALVE
• The ball valve, for on/off control without pressure drop, and
ideal for quick shut-off since a 90° turn offers complete shut-off angle,
compared to multiple turns required on most Manual valves
• Butterfly valve, for flow regulation in large pipe
diameters.
• Choke valve, a valve that raises or lowers a solid cylinder
which is placed around or inside another cylinder which has holes or slots.
Used for high-pressure drops found in oil and gas wellheads
• Check valve or non-return valve, allows the fluid to pass
in one direction only
HASTELLOY CHECK VALVE
·
Diaphragm valve, some are sanitary predominantly
used in the pharmaceutical and Foodstuff industry.
·
Ceramic Disc valve, used mainly in high duty
cycle applications or on abrasive fluids Ceramic disc can also provide Class IV
seat leakage
·
Gate valve, mainly for on/off control with low
pressure drop.
STAINLESS STEEL GATE VALVE
·
Globe valve, good for regulating the flow
·
Knife valve, for slurries or powders on/off
control.
·
Needle valve for accurate flow control.
·
Piston valve, for regulating fluids that carry solids
in suspension
·
Pinch valve, for slurry flow regulation.
·
Plug valve, slim valve for on/off control but
with some pressure drop.
·
Spool valve, for hydraulic control
·
Thermal expansion valve, used in refrigeration
and air conditioning systems.
·
Poppet valve
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