Piping Engineering: PFD, PID, SIF, and ASME B31 Standards
Posted by Anonymous and classified in Other subjects
Written on in 
English with a size of 35.32 KB
Objectives of PFD and PID
PFD (Process Flow Diagram): Illustrates major equipment and the flow of process fluids.
PID (Piping and Instrumentation Diagram): Details piping, instruments, and valves required for operation and control.
SIF and Its Significance
The Stress Intensification Factor (SIF) accounts for increased stress at fittings such as bends and tees. It is essential for flexibility and stress analysis (e.g., CAESAR II) to ensure piping integrity under cyclic loading.
Miter Bend Spacing Analysis
Given:
- O.D. = 8.0662 in
- Mitre spacing = 6.0438 in
Check:
For widely spaced: Spacing > 2 × pipe diameter
2 × 8.0662 = 16.1324 in
6.0438 < 16.1324 → Not widely spaced
Pipeline Designation Standards
Designations include pipe size, schedule, material, rating, and service. Example: 8" NB, SCH 40, ASTM A106 Gr. B, 150#, Steam Service. This ensures correct selection and specification.
Salient Features of ASME B31
- Provides design, fabrication, and inspection standards.
- Covers diverse industries (e.g., B31.1 Power, B31.3 Process).
- Addresses stress, flexibility, material properties, and corrosion.
- Ensures global safety and reliability in piping systems.
PID of Sulfuric Acid Manufacturing
Feed Section: Air is filtered and compressed; blower and air filter are shown with flow arrows.
SO2 Generation: Sulfur is burnt in a furnace to produce SO2 gas, monitored by a temperature control loop.
Gas Cooling: Heat exchangers reduce SO2 temperature using cooling water loops and temperature indicators.
Catalytic Converter: SO2 is converted to SO3 over catalyst beds, represented as reactors with temperature gauges.
Absorption Tower: SO3 is absorbed in H2SO4 to form more acid; the tower includes level indicators, acid pumps, and recirculation loops.
Pumps & Valves: Centrifugal pumps, motor symbols, control valves, and check valves are clearly marked.
Instrumentation: Temperature (TIC), Pressure (PIC), and Flow (FIC) controllers are used alongside DCS/PLC symbols for automation.
Utilities: Steam lines, cooling water, and instrument air lines are included.
Legend Block: Explains all symbols used for pumps, valves, and lines.
Pipe Thickness Calculation
Given Parameters:
- Allowable stress = 1500 kg/cm²
- Outer diameter (D) = 21.9 cm
- Corrosion allowance (C) = 0.15 cm
- Weld factor (W) = 0.4
- Allowable tolerance = 12.50%
- Joint efficiency (E) = 0.9
- Design pressure = 2 kg/cm²
- y = 0.4
Calculation Results
- Required Thickness (T): 1.8996 mm
- Calculated Thickness (t): 0.1621 mm
- Sharp Thickness (t): 1.6621 mm