MIDDLE EAST TECHNICAL UNIVERSITY

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MIDDLE EAST TECHNICAL UNIVERSITY

• DEPARTMENT OF CHEMICAL ENGINEERING
• Presented by JARKYN JUMABAEVA
• GÜLBANU ALSAN

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VALVES

• Used in piping systems and processing vessels or
  tanks.
• FUNCTIONS
• On-off service
• Throttling service
• Prevention of reverse flow
• Pressure control
• Special functions
• Directional flow control
• Sampling service
• Limiting flows
• Sealing vessels or tank outlet nozzles

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TYPES OF VALVES

• Special service valves
• Pressure relief valve
• Control valve

• General purpose valves
• Gate valve
• Globe valve
• Plug valve
• Ball valve
• Butterfly valve
• Diaphragm valve
• Pinch valve
• Slide valve

• Check valves
• Swing valve
• Titling valve
• Lift valve
• Spring loaded valve

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GATE VALVE

• They are linear motion valves in which a flat
  closure element slides into the flow stream to
  provide shut-off.
• These valves are designed to minimize pressure
  drop across the valve in the fully opened
  position and stop the flow of fluid completely.
• USED FOR
• Fully opened or fully closed operations
• They are also used in applications that involve
  viscous liquids such as heavy oils, light grease
  and other non-flammable viscous liquids.

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USED WITH

• Ideal for a variety of services within the
  chemical industry and for arduous working
  conditions on slurries, resins and fibers

GATE VALVE DESIGN

• When valve is wide open,the wedge or gate is
  lifted out of the waterway,providing a
  straignt-way path througn the valve.
• Gate valve offer less resistance to flow because
  the seating is at right angles to the line of
  fluid flow.

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TWO DIFFERENT DISC GESIGN

• Wedged ( solid, flexible and split )-use two
  inclined seats and a slightly mismatched inclined
  gate allowing for tight shut-off.
• Parallel ( knife )-uses a flat disc gate between
  two parallel seats, upstream and downstream.

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WEDGE SHAPED

• Solid wedged valve

• A  valve  with  this  type  of  wedge  may  be
   installed  
• in  any position and it is suitable for almost
  all fluids.
•  It is practical for turbulent flow.

Flexible wedged valve
The  flexible  wedge  gate  valve is  a one-piece
 disk with  a  cut around  the  perimeter to
 improve the ability to match error or change in
the angle between the seats
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Split wedged valve

• They are suitable for handling noncondensing
  gases and liquids at normal temperatures,particula
  rly corrosive liquids

PARALLEL
Knife valve

• May be used in wet or dry services
• easily dealing with large,
• heavy particles and tramp material
• Unobstructed flow eliminates turbulence,
• minimizes pressure drop across valve

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GLOBE VALVE

• Globe valves are linear motion valves with
  rounded bodies, from which their name is derived.
  
• It is acceptable in a wide variety of industrial
  application from light industrial, petrochemical
  and power industries.

USED FOR

• Regulating fluid flow in both
• on/off and throttling service
• High pressure drops and high
• temperature applications
• Used where some fluid trapped in line is not
  objecionable

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GLOBE VALVE DESIGN

• The location of the valve disk in relation to the
  valve seat allows or restricts flow. 
• Globe valves are installed with the stem
  vertical and the higher-pressure fluid stream
  connected to the pipe side above the disk.

TYPES OF GLOBE VALVES
Angle type Y-type

Multi-piece (needle) type
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• Angle type valves - are designed so that the
  inlet and outlet are perpendicular, for
  transferring flow from vertical to
  horizontal.
• Y type valves - derive linear action from the
  incline between the axis of the inlet and
  outlet ports.
• Multi piece design valves- are bolted together. 
  The inlet and outlet are not of single piece
  construction

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PLUG VALVE

• Plug are valves with cylindrical or
  conically-tapered "plugs" which can be rotated
  inside the valve body to control flow through the
  valve.
• USED FOR
• Nonthrottling on-off operations
• suitable for corrosive, abrassive
• and critical service applications
• ADVANTAGES
• Minimum resistance to flow and low pressure drop
• Easily adapted to multiport construction

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PLUG VALVE DESIGN

• Plug is round or cylindrical
• Have various types of port
• openings
• Made from
• Bronze Stainless steel
• Brass Steel
• TFE-lined Polyvinylchloride (PVC)
• Ni-resist Penton

TYPES OF PLUG VALVES

• Lubricated
• Non-lubricated

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BALL VALVE

• A ball valve is a valve that opens by turning a
  handle attached to a ball inside the valve
• Serve in the chemical, pharmaceutical, oil,
  petrochemical and allied process industries
• USED FOR
• Suitable for wide pressure range
• Quick opening
• ADVANTAGES
• Minimum resistance to flow
• Limited to moderate temperature services

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BALL VALVE DESIGN

• Floating a polished ball between two plastic
  O-ring seats, permitting free
• turning of the ball
• They are easy to maintain, require no lubrication
  and give tight sealing with low torque
• TYPES
• Full port
• Standard port
• Reduced port
• V port

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BUTTERFLY VALVE

• Butterfly valves are available in a variety
• of materials suitable for applications in
• the marine, water and process industries
• Savings in weight, space and cost are the
• most obvious advantages
• USED FOR
• Handling of large flows of liquids,gases at low
  pressures
• and slurries with large amounts of suspended
  solids
• Suitable for throttling as well as open- closed
  applications
• ADVANTAGES
• Low pressure drop across the valve
• Minimum amount of fluid trapped in the line

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DESIGN

• A smooth circular disc is positioned in the
  middle of the pipe mounting connection is either
  welding connection or between flanges
• Rotating the handle turns the plate either
  parallel or perpendicular to the flow of water,
  shutting off the flow.
• TYPES
• Wafer connection
• Flanged connection
• Lugged connection

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DIAPHRAGM VALVE

• Diaphragm valves use an elastomeric diaphragm to
  separate the flow stream from the closure element
• Their application is generally as shut-off valves
  in process systems within the food and beverage,
  pharmaceutical and biotechnology industries
• USED FOR
• Handling of slurries, highly
• corrosive materials or materials to be protected
  from contamination
• ADVANTAGES
• Low operating pressures
• Fully opened, fully closed or throttling services

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DESIGN

• Resilient flexible diaphragm is connected to a
  compressor by a stud molded into the diaphragm

• MATERIAL OF CONSTRUCTION
• Cast iron
• Cast steel
• PVC
• Colypropylene

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PINCH VALVE

• Includes any valve with a flexible elastomer body
  that can be pinched closed, cutting off flow
  using a mechanism or fluid pressure
• SOME ADVANTAGES
• Low maintenance cost
• Low weight due to large plastic body
• Low pressure drop
• Moderate temperature services
• Excellent drainage,ease of cleaning
• Straight through design allowing for a high rate
  of flow with minimal turbulance

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USED FOR

• On-off and throttling services
• Handling of slurries,liquids with large amounts
  of suspended solids
• Used in wastewater,powder,pellets and medical
  applications
• Suitable for food applications when utilised with
  a food grade sleeve
• PINCH VALVE DESIGN
• A flexible hose is pinched between one or two
  moving external elements to stop the flow
• Pinching action is made by air or hydraulic
  pressure placed directly on the elastomer sleeve
  

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SLIDE VALVE

• Some advantages are
• Simple to set up
• Easy to maintain
• Lasting for a long period with minimal
  maintenance
• USED FOR
• Handling liquids or gases containing a high
  percentage of solids,pulp stock and free flowing
  granular materials
• Controlling low pressure flow of gases, liquids,
  suspensions and fluidized solid
• Applications where tight closure is not required
• Coping with a wide range of power and speed
  demands

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• SLIDE VALVE DESIGN
• Flow is controlled by means of a gate or blade
  which slides between parallel body seats
• The blade is completely removed from the fluid
  way when the valve is in open position

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SWING CHECK VALVE

• They allow full unobstructed flow opening with
  line pressure and automatically closing as
  pressure decreases
• USED FOR
• Minimum resistance to full unobstructed flow
• Liquid service
• Low velocities
• Infrequent change of direction
• Service in lines with gate valves

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• DESIGN
• Must be installed with flow pressure under disc
• The plugs on each side hold in place the hanger
  pin which permits the disc to swing
• TYPES
• Y-Pattern
• Straight through
• Y-pattern check valves are designed with an
  access opening in line with seat
• Straight through pattern check valves contain a
  disc that is hinged at the top

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TILTING DISC CHECK VALVE

• They keep fluid resistance and turbulance low
  because of its straight through design like swing
  check valve
• USED FOR
• Liquid or gas services
• Minimum resistance to flow
• Frequent change of direction
• Service lines using gate valves

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TILTING DISC CHECK VALVE DESIGN

• Some designs simply fit between two faces
  providing a compact,lightweight installation
  particularly in larger diameters
• As flow decreases the disc starts closing and
  seals before reverse flow takes effect
• Inlet flow side is opposite to the direction of
  the disc travel

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LIFT CHECK VALVE

• They are generally employed
• in all plastic and graphite check valves
• Some standard materials of construction in lift
  check valves are bronze,all iron,cast iron,
  stainless steel and polyvinyl chloride (PVC)

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USED FOR

• Piping systems in which globe valves are being
  used as the flow control valve
• Steam, water, gas and on vapor lines with high
  velocities
• Air service with composition disc
• Frequent change of directions
• Recommended with globe and angle valves

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LIFT CHECK VALVE DESIGN

• Flow to lift check valve must enter below the
  seat
• As the flow enters, the disc is raised by the
  pressure of the upward flow
• TYPES
• a) Horizontal b) Angle
  c)Vertical

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SPRING LOADED CHECK VALVE

• These valves rely on a small internal spring to
  close the valves disc whenever the fluid is not
  moving in the intended direction

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• USED FOR
• Easy maintenance,respond to certain water
  pressure
• Opening from 2 to 15 psi (1.02 atm)
• Liquid or gas service and for positive sealing
• Frequent reversal of flow
• Never jam or stick due to rust or corrosion
• Not contaminating sensitive fluids that come into
  contact with them

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• SPRING LOADED CHECK VALVE DESIGN
• The valve opens whenever fluid pressure on the
  inlet side of the valve exceeds the tension of
  the spring
• These valves are hand adjustable and can be set
• The double seal design of the valve ensures seal
  integrity and long life
• There is no need to remove the valve from piping
  system for service

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PRESSURE RELIEF VALVE

• It is a special service valve that protects
  against excessive pressure
• USED FOR
• Relieving excessive pressures developed by
  noncompressible fluids
• Available from cryogenic temperatures up to
  approximately 1500F (815C) and from full vacuum
  up to 10000 psi (680 atm)

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• PRESSURE RELIEF VALVE DESIGN
• The area exposed to the overpressure is the same
  whether the valve is open or closed
• Valve disc is lifted from its seat as pressure
  increases until valve reaches the full open
  position

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CONTROL VALVE

• They are power operated devices used to modify
  fluid flow or pressure rate in a process system
• USED FOR
• Controlling temperature,pressure,flow, liquid
  level or some other process variable
• Process control,oil or fuel,wastewater,
  water,irrigation,gas or air,steam,fire service,
  chemicals,laboratory or medical

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CONTROL VALVE DESIGN

• Automatic operators can be incorporated into an
  automatic control circuit with the valve
  operation being performed on signal from a
  control unit which controls the desired process
  variables

Cross section of a standard globe style control
valve with throttling cage
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REFERENCES

• Philip A., Swheitzer, Handbook of Valves,
  Industrial Pres Inc., Newyork, 1972
• http//controlvalves.globalspec.com/LearnMore/Flow
  _Control_Flow_Transfer/Valves
• http//cms.fountainpark.org/onninen/638
• http//www.legendvalve.com/gatevalves.htm
• http//www.tradekey.com/index.html?actionproduct_
  viewimagesuid426883id129958
• http//www.teecoproducts.com/catalog/A24.htm
• http//www.matconorca.com/brass_gate_valves.htm
• http//www.cranevalve.com/crane.htm

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THANK YOU

• PREPARED BY GROUP-J
• GÜLBANU ALSAN
• JARKYN JUMABAEVA