Pressure Safety Devices
“Grace Under Pressure”
-Earnest Hemingway
Faizan Ahmad
ICET, Punjab University
Lahore, Pakist...
Pressure Terminologies
 Accumulation
 Design Pressure
 Set Pressure
 Operating Pressure
 Overpressure
 Underpr...
Causes of Over Pressure Causes of Under Pressure
Operating Problem Operating Problem
Equipment Failure Equipment Failure...
Safeguards
 Safety Interlocks
 Safeguard Maintenance Systems
 Short Stopping
Safety Interlocks
 Agitator not working
 Abnormal Temperature
 Abnormal Pressure
 Abnormal Heat Balance
For all t...
Safeguard Maintenance System
 Routine Maintenance
 Mechanical Integrity Checks
 Records
Short Stopping
 Add React...
Reliefs
Pressure Relief Devices
1. Spring-Loaded Pressure Relief Valves
2. Rupture Disc
3. Buckling Pin
4. Miscellane...
Spring Loaded Pressure Relief Valve
Rupture Disc
Buckling Pin Relief Valve
Closed Pressure below
Set Pressure
Full Open Pressure at or
above Set Pressure
(Buckles in ...
Simple Mechanical Pressure Relief
Other Types of Safety Valves
 Balanced Bellows
 Pilot Operated
Balanced Bellows Safety Valve
Pilot-Operated Safety Valve
When to Use Spring-Operated Safety
Valve
Spring-Operated Valve is used in following cases
 Fluids above normal boiling...
When to Use Rupture Disc/Safety pin
Valve
 Capital and maintenance savings
 When fluid is not so expensive
 For Ben...
When to Use Both Types
 Need a positive Seal (Toxic Material, Material
Balance Requirements)
 Protect Safety Valve fo...
Anything wrong
here?
Bellows plugged
in spite of sign
Failed
Inspection
Program
Signs of
Maintenance
Issues
Anything wrong
here?
Anything wrong
Discharges
Pointing here?
Down
Mexico City Disaster
Major Contributing Cause: Missing
Safety Valve
References:
Mohammad A. Malek --- Pressure Relief
Devices Chapters # 1, 3, 21
Crowl, Louver --- Chemical Process Safety...
End of Presentation
Thank-you
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Pressure safety devices

Slide for Safe Operation of Pressure Vessels. and the safety of Pressurized Vessels by using Pressure Safety Devices.
Published on: Mar 4, 2016
Published in: Engineering      
Source: www.slideshare.net


Transcripts - Pressure safety devices

  • 1. Pressure Safety Devices “Grace Under Pressure” -Earnest Hemingway Faizan Ahmad ICET, Punjab University Lahore, Pakistan
  • 2. Pressure Terminologies  Accumulation  Design Pressure  Set Pressure  Operating Pressure  Overpressure  Underpressure  Popping Pressure
  • 3. Causes of Over Pressure Causes of Under Pressure Operating Problem Operating Problem Equipment Failure Equipment Failure Process Upset Utility Failures
  • 4. Safeguards  Safety Interlocks  Safeguard Maintenance Systems  Short Stopping
  • 5. Safety Interlocks  Agitator not working  Abnormal Temperature  Abnormal Pressure  Abnormal Heat Balance For all these Abnormalities: Stop Feed and Add full Cooling
  • 6. Safeguard Maintenance System  Routine Maintenance  Mechanical Integrity Checks  Records Short Stopping  Add Reaction Stopper  Add Agitation with no Electrical Power
  • 7. Reliefs Pressure Relief Devices 1. Spring-Loaded Pressure Relief Valves 2. Rupture Disc 3. Buckling Pin 4. Miscellaneous Mechanical Means
  • 8. Spring Loaded Pressure Relief Valve
  • 9. Rupture Disc
  • 10. Buckling Pin Relief Valve Closed Pressure below Set Pressure Full Open Pressure at or above Set Pressure (Buckles in precise milliseconds at a precise set Pressure)
  • 11. Simple Mechanical Pressure Relief
  • 12. Other Types of Safety Valves  Balanced Bellows  Pilot Operated
  • 13. Balanced Bellows Safety Valve
  • 14. Pilot-Operated Safety Valve
  • 15. When to Use Spring-Operated Safety Valve Spring-Operated Valve is used in following cases  Fluids above normal boiling point  Used where toxic fluids are handled  Return to normal conditions quickly Withstand process pressure changes, including vacuum  When fluid is of the Prime Importance
  • 16. When to Use Rupture Disc/Safety pin Valve  Capital and maintenance savings  When fluid is not so expensive  For Benign Service (Non-toxic, Non-Hazardous)  Need for fast acting device  Potential for Relief valve plugging  Used for High Viscosity Liquids
  • 17. When to Use Both Types  Need a positive Seal (Toxic Material, Material Balance Requirements)  Protect Safety Valve for Corrosion  System Contain Solids
  • 18. Anything wrong here? Bellows plugged in spite of sign Failed Inspection Program Signs of Maintenance Issues
  • 19. Anything wrong here? Anything wrong Discharges Pointing here? Down
  • 20. Mexico City Disaster Major Contributing Cause: Missing Safety Valve
  • 21. References: Mohammad A. Malek --- Pressure Relief Devices Chapters # 1, 3, 21 Crowl, Louver --- Chemical Process Safety Chapter # 8
  • 22. End of Presentation Thank-you

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