Page 229 - Applied Process Design For Chemical And Petrochemical Plants Volume II

21 8 Applied Process Design for Chemical and Petrochemical Plants

Vertical Alignment From,,Base to Top of Trays out of Level to a
Top shall be within 0.01 per Horizontal or Designated Plane
Foot with a Maximum of 314" Along Any Diameter ,and Variation
for any Height From True Flatness.
1/8" Max. for Trays under 36" Dia.
3/16" Max. for Troys 36" to 60" Dia
Bend Line to Bend Line
+ 3/4"- 0" 114" Max. for Trays over 60" Dia.

Location of Any Tray from
Reference Line f 1/4"

Face of any Nozzle to g of
Shell Diameter ASME Co Column k 1/81!
To 1 era n ce

Height of Downcomer Weir
5 1/16
Location of Any Nozzle from
Height of Distributor Weir Reference Line f 1/4"
5 1/16"
Bottom of Down Spout Above
Far Side of Tower to Weir Tray or Seal 2 1/8'
Plate 2 1/4l'
Location of Any Lugs from
Alignment of Monway Flange Reference Line f 1/4"
Face shall be within 1' in Both
Vertical 8 Circumferential Plan

Location of Manway from
Reference Line 2 1/211

Reference Line Alignment Taleranee
For all Connection Nozzles

Max. Measured of Extrem
Outer Edge of Base Plate Tolerances are Not Cumulative
Flgure 8-157. Suggested tolerances for distillation type towers.

(text continuedfiom page 215) The towers are designed in accordance with the partic-
ular code (such as MME Unfired Pressure Vessel) used
stainless, alloy steel, monel or nickel trays, caps and all by the company or required by law. To provide stiffness
internal parts. Sometimes just the cap or hole portion of and bending strength in high winds, design normally fig-
the trays are of expensive construction. ures a wind load recommended for the area. It is not
When clad metal is used, it is often specified as %in. or unusual to design for 75 to 100 mph winds, taking into
%in. minimum clad thickness. This is usually sufficient to account the external insulation, piping, ladders and plat-
allow proper weld connections. Care must be used in seal- forms in computing the effective force areas. Founda-
ing all internal joints of clad material to prevent exposure tions must be adequate to carry the total dead weight of
of the base metal. the erected tower, platforms, etc. plus the weight of water