introduction of PRESSURE VESSELS and piping

Pressure Vessels: Pressure vessels are containers designed to hold gases or liquids at a pressure substantially different from the ambient pressure. They are essential in various industries, including chemical, petrochemical, oil and gas, power generation, and food processing. Their design, fabrication, and operation are critical because the high-pressure conditions present hazards such as explosions or leaks if not properly managed.Key Characteristics:

Shape: Typically cylindrical, spherical, or conical to evenly distribute stress.
Material: Constructed from steel, stainless steel, aluminum, or composite materials to handle high pressures and corrosive environments.
Design Considerations: Must adhere to strict codes and standards such as ASME Boiler and Pressure Vessel Code to ensure safety and reliability.
Common Applications:
Boilers (steam generation)
Reactors (chemical processes)
Storage tanks (gas and liquid storage)
Types of Pressure Vessels:

Spherical Vessels: Used for very high-pressure applications due to even stress distribution.
Cylindrical Vessels: Common for lower-pressure applications, easier to fabricate.
Horizontal or Vertical Vessels: Based on space requirements and the specific application.
Piping Systems: Piping is a network of pipes used to transport fluids (liquids, gases, or slurries) from one location to another. Industrial piping is an integral part of pressure vessels since it facilitates the movement of fluids into, within, and out of the vessel.

Key Characteristics:

Material: Carbon steel, stainless steel, PVC, or HDPE, depending on the nature of the fluid and operating conditions (pressure, temperature, corrosiveness).
Fittings and Valves: Piping systems include various components like elbows, tees, reducers, flanges, and valves to control flow and connect sections.
Design Standards: Like pressure vessels, piping systems follow industry standards such as ASME B31.3 (Process Piping) for safe operation.
Types of Piping Systems:

Process Piping: Used in industrial plants to transport process fluids (oil, gas, chemicals).
Power Piping: Found in power plants for handling steam, water, and other fluids.
Plumbing Systems: Commonly used in residential and commercial buildings to carry water and sewage.
Applications of Pressure Vessels and Piping:

Oil and gas refineries
Power plants (nuclear, fossil-fuel, hydro)
Water treatment facilities
Food and beverage processing plants
Pharmaceutical industries

1. PRESSURE VESSELS

2. PRESSURE VESSELS Cylinder Cylinder is a mechanical device used for storing ,receiving processing the fluid . Cylinder may be Pressure vessel Storage vessel Pipe Engine cylinder Cylindrical Pressure Vessel Thin Cylinder :- If The ratio of d i / t > 15 Thick cylinder :- if the ratio d i / t < 15

3. Stresses in Thin Cylinder Circumferential or Hoop Stress , σ t Longitudinal Stress, σ l Radial Stress, σ r Radial stress is equal to internal pressure at inner surface and zero at outer surface. Forces due to internal pressure are balanced by shear stresses in wall.

4. Thickness of Thin Cylinder It is observed that circumferential stress is twice the longitudinal stress By Considering longitudinal and circumferential joints equation is modified as, η c = Efficiency of Circumferential Joint η l = Efficiency of Longitudinal Joint

5. Stresses in Thin Spherical Vessels Circumferential or Hoop Stress : Thickness of Pressure Vessel The Capacity of the Spherical Vessel,

6. Thick Cylinders Considering Equilibrium of vertical forces acting on half portion of ring, It is assumed that longitudinal stress is constant over the cylinder wall thickness. The longitudinal strain e l ……..a

7. Thick Cylinders The modulus of elasticity E, Poisson's ratio v , longitudinal strain are constant. Therefore right hand side is constant and is denoted by 2A Subtract equation ( a) from ( b) By Integrating We get, B = constant of integration ………………………….b

8. Thick Cylinders We can write as, Substitute in equation ( c) in equation.. ( b) The A and B can find by using following boundary condition, At, ………………………………c

9. Thick Cylinders We get, By Substitute value of B, We get By substituting A and B,

10. Thick Cylinders Putting Boundary following Condition, At,

11. Thick Cylinders The longitudinal stress, by considering forces in axial direction,

12. Thick Cylinders Sr. NO. Principal Stress Inner Surface Outer Surface 1. Circumferential Stress 2. Radial Stress 3. Longitudinal Stress

13. Pre- Stressing of Thick Cylinders Autofrettage Wire Wound Cylinders Tape Wound Cylinders Compound Cylinders

14. Wire Wound Cylinders Tape Wound Cylinders

15. Compound Cylinders

16. Stress Distribution in Compound Cylinder

17. Residual Stresses Due to Shrink Fit Sr. No. Parameter Residual Stress at Inner Surface Residual Stress at Outer Surface Jacket (Outer Cylinder) 1. σ t 2. σ r -p (Inner Cylinder) 1. σ t 2. σ r -p

18. 1. Increase in Inner Diameter of Jacket (Outer Cylinder) 2. Decrease in Outer Diameter of Inner Cylinder

19. Classification of Unfired Pressure Vessel Class 1 Class 2 Class 3

20. Types of Welded Joints in Used Pressure Vessel

21. Categories of Welded Joints in Unfired Pressure Vessel Category A Category B Category C Category D

22. Materials Used for Unfired Pressure Vessel Cast Irons Plain Carbon Steels Alloy Steels Aluminum Steels Copper and Copper Alloys Nickel and Nickel Alloys

23. Selection of Design Parameters for Unfired Pressure Vessels Maximum Working Pressure ( P max ) Design Pressure (P i ) P i = 1.05 P max Hydrostatic Test Pressure ( P b ) P b = 1.3 P i Allowable Stress, Corrosion Allowance (c) As per IS code As per ASME code As per DIN code

24. Stress in Thin Cylinder Forces due to internal pressure are balanced by shear stresses in wall Horizontal section: Vertical section: Similar equations can be derived for other geometries such as heads (see Ch 13)  H  L Longitudinal stress,  L Hoop stress,  H Inside diameter, D Wall thickness, t Height, h