Openings mainly in Windward wall: C_pi = 0.7
    Openings mainly in Leeward wall: C_pi = 0.5
    Openings mainly in walls Perallel to the wind direction: C_pi = -0.7
    Openings uniformly distributed in All 4 walls: C_pi = -0.3

    Reference height for C_e, one-half of height. When there are dominant openings in the windward wall, use the highest opening.

1. Tributary width for piping:
  Based on the diameter of the largest pipe + 10% of the width of the piperack.
  C_f = 0.7, C_g = 2.0

2. Tributary width for cable trays:
  Based on the height of the largest tray + 10% of the width of the piperack.
  C_f = 2.0, C_g = 2.0

3. Frames for piping and equipment:
  Frame wind load + equipment wind load + piping wind load for one axis, acting simultaneously with 50% of the frame wind load along other direction.

4. Vertical Vessels:
  Projected width = the diameter of vessel + 5 feet, or the largest piping diameter + diameter of vessel + 3 feet.
  Projected height = the diameter of vessel + the height of the vessel.
  For h/D, they should be the original values.

5. Horizontal Vessels:
  Projected diameter = the diameter of insulated vessel + 1.5 feet.
  C_g = 2.0
  For transverse wind: C_f = 1.12, factor (0.7) to account for the cylindrical shape.For L/h =10 and d = 40, C_f = 1.6 x 0.7 = 1.12
  For longitudinal wind, C_f = 1.5
6. Spheres:
  Projected diameter = the diameter of insulated vessel + 1.5 feet.

7. Appurtenances:
  F = q . C_e . C_g . C_f . A
  Ladders: C_f = 2.0; A = 0.1524 m²/m for ladder without cage, A = 0.2286 m²/m for ladder with cage.
  Handrails: C_f = 2.0; C_g = 2.5, A = 0.25 m²/m
  Platforms: C_f = 2.0; C_g = 2.5, A = projected area of supporting steel.