DESIGN CALCULATIONS FOR 20 KL (WC) LPG STORAGE TANK

Designed by: Kushagra Checked by: Approved by:

Drawing No.: SSVPL-AG-BSI-001 Date: 27-Dec-12

DESIGN DATA

Code of Design : IS: 2825 CLASS-1, 2000 + SMPV (U) RULES 1981

Inspection By : Any CCE approved Inspection Agency

Type of Tank 1 : Above Ground

Liquid Stored : LPG

Internal Pressure (Kg/cm2) : 21

Static Head (kg/cm2) : 0.23For Water

Internal Design Pressure with static head (Kg/cm2) : 14.5

External Design pressure : 0

Test Pressure (Kg/cm2) : 14.73

Design Temp. (Deg C) : (-) 6 to (+) 55

Wear & tear Allowance : 1.5

Radiography : Full

Joint Efficiency : 1

Water capacity (m3) : 20.000

Gas Capacity (MT) : 9.41

Seismic (Earthquake load) : As per IS: 1893 & locationHeat Treatment : Full Stress Relieving

Internal Diameter : 2300 mm

Manhole Diameter (mm) : 457Assumed Thickness of Dish End (mm) : 12

Density of Water / LPG (kg/cu m) : 1000 495

MATERIAL SPECIFICATION

Shell: SA 516/516M Gr. 70 Cl. 1

Dished End / Pad: SA 516/516M Gr. 70 Cl. 1

Flanges / Couplings : SA 105

Pipes : SA 106 Gr. B

Studs & Nuts: A 193 Gr. B7 / A194 Gr. 2H

Gasket : Spiral wound SS-304VOLUMETRIC CALCULATIONS

Type of Dish End : Torispherical

Assumed thk. Of D/End (td) (mm) : 12

Volume of Tank (V) (m3) : 20

Inside Diameter (Di) (m) : 2.3

Inside Radius (ri) (m) : 1.150

Crown Radius (Cr) (mm) : 1840

Knuckle Radius (Kr) (mm) : 368

Volume of 2 Nos D/End (m3) : 3.56

Volume of Cylindrical Shell (m3) : 16.44

Cylindrical Shell Length (m) : 3.956

Cylindrical Shell Length (L) (mm) : 3956

Out Side Head Height (h) (mm) : 655

Overall Length (mm) : 5266SHELL THICKNESS CALCULATIONS

Design Pressure (kg/cm2) : 14.73

Corroded Inside Diameter (mm) : 2303

Max. Allowable Stress (kg/cm2) : 16.403

Joint Efficiency : 1

Minimum Shell Thickness (t min) (mm) : 10.37

Minimum Shell Thickness Including corrosion Allowance

T min + corrosion allowance (mm) : 11.87

Provided Nominal Shell Thickness (mm) : 12 mm

DISHEND THICKNESS CALCULATIONS

Type of Dish End : Torrispherical

Design Pressure (kg/cm2) : 14.73

Value of C (From IS: 2825-1969 fig-3.7 for Compensated Ends) : 0.9

Minimum Thickness of Dish-End as Eq.3.15 of IS: 2825-1969 (mm) : 9.39

Thinning Allowance & Corrosion Allowance (mm) : 2.439

Minimum Shell Thickness Including corrosion Allowance

T min + corrosion allowance (mm) : 11.83

Provided Nominal D/End Thickness (mm) : 12 mm

SAFETY VALVE SIZING CALCULATIONS

Calculation as per NFPA No. 58-1991, Appendix A

Type of Tank : Above Ground

External Surface Area (ft2) : 468.5

Required Discharge (CFM) : 8306.64

Against this, 2 Nos. of 2" NB Safety Relief Valves having capacity of 13000 CFM each are to be provided.

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