industrial process control. valves used in paper and pulp industry. valve selection and description. instrumentation and control engineering.

1. Valves used in Paper
Industry
Submitted By,
Santosh Kumar Manchal
S7
ICED
Faculty in
Charge,
Nikhil Benoy
C
Associate
Professor
ICED

2. What are Valves?
•A valve is a device that regulates, directs or controls the flow
of a fluid (gases, liquids, fluidized solids, or slurries) by opening,
closing, or partially obstructing various passageways.
•Valves are technically fittings, but are usually discussed as a
separate category.
•In an open valve, fluid flows in a direction from higher pressure
to lower pressure.
•The word is derived from the Latin valva, the moving part of a
door, in turn from volvere, to turn, roll.

3. Selection Factors
•Control and Regulation
•Valve Characteristics
•Actuation
•Application
•Valve’s range-ability to give a satisfactory control
•Absence of undesirable noise
•Tight Closure
•Freedom from plugging, erosion and cavitation
•Ability to withstand drastic pressure variation and high pressure and temperature.
•Resistance to process fluid
•Compatibility

5. Valve Types
•Ball Valve
•Butterfly Valve
•Gate Valve
•Plug Valve
•Pinch Valves

6. Ball Valves
•Widely available in two type of opening
structures
• Fully Open and V-Notch
•Basically a plug valve with a spherical plug and
a hole
•Tight Shutting
•Equal Percentage characteristic
•Can pass dense slurries at lower velocity easily
•High-Recovery Valves

7. Ball Valve
•Can be used at pressures of up to 700 bars i.e. around
10k PSI
•Two primary options for design are
• Floating – low cost operations
• Trunnion Ball – high duty operation
•Reduced bore design to allow smaller body but still with
relative low head loss
•Low Actuation Torque
•Poor for throttling, causes erosion of seat

8. Butterfly Valves
•Used to control liquid and light slurries.
•Produce a reasonable tight shut-off.
•Show initial equal % chara which tends toward linear chara as flow
coefficient and opening increases.
•High flow Capacity.
•Low Pressure drop.
•Wide range of size and material
•Low installation cost.
•Easy service and installation
•Low cost
•Available in large size

9. Butterfly Valves
•The closure pivot axis is usually in direction of flow
•Very precise
•Can be used for on-off and throttling condition
•Metal to Metal seats are not bubble tight
•Lined types are subjected to linear failure at high pressure
•Minimizes plugging
•The disc acts as an obstruction to flow
•Foreign materials gets trapped b/w disc and body

10. Gate Valves
•Used in ON-OFF services and on remote manual line switching application.
•Provide the most economic and practical mean of switching and isolating large stock piles
•Obstruction- less flow
•Can be used with slurries and viscous fluids
•Less Expensive
•Easy to maintain and dis-assemble
•Sizes available – 5mm-2000mm

12. Gate Valves
•Not Preferred as regulators in high pressure system.
•Slow
•Require large actuators when dirt medium comes in
contact with valve gate
•Erodes in abrasive services.
•Poor throttling and difficult to repair
•Noisy in high pressure systems

13. Plug Valve
•Used to stop and start flow. Basically a ON-OFF
valve
•Used in arduous conditions, e.g. nuclear
industries
•Is usually engineered with a lubricated plug.
•Ideal for slurries and dense liquid applications
•No internal cavities, full bore
•High Capacity
•Effective Control characteristics
•Moderate cost
•Require higher actuators

14. Pinch Valves
•Theoretically ideal solution for fluids ON-OFF duties.
•Employees an elastomaterial for squeezing the tube when shut
off is required.
•Are fair when used for stocks and high density slurries.
•Pinch diameter – 25mm - 1000nn
•Pressure – 0-100 bar
•The liner should be selected so that its not damaged by
downstream vacuum.

15. Thank You 