Double Diameter Tower Estimation App
Pressure/vacuum, includes vessel shell, heads, transition section, single base material, lined or clad, nozzles, manholes (one manhole below and above tray stack or packed section and one manhole every tenth tray or 25 FEET [7.6 M] of packed height), stiffening rings if desired, base ring, lugs, skirt or legs; tray clips, tray supports (if designated), distributor piping, plates, packing (if packing designated ); variety of applications for plate and packed towers: absorption, desorption, distillation or stripping (via kettle or thermosiphon reboiler defined separately), extraction; applications for packed towers:
gas and liquid adsorption; sections can be trayed, packed, empty. Ladders and platforms not included. (See Single Diameter Towers for tray stacks.)
Materia Cost Factors can vary dramatically and should be used with judgement.
- Obtain the costs for Vessel Shells and Heads from tables shown, diameters from 24″ through 144″ based on the thickness and type of Plate used and the type of X-Ray inspection are included.
- Cost for Stress Relief is not included and must be added when mandatory or required by design.
- The Shells are shown with a net theoretical fabricated weight in pounds per lineal foot. When estimating Vessel weights, Stress Relief costs, and Freight costs, Shell weights should be increased by the following percentages to allow for overweights:
Add For Overweights
|1/2″ & 9/16″||6.00%|
|5/8″ & 11/16″||5.25%|
|3/4″ Through 2″||4.50%|
The above percentage represents 75% of the maximum allowable overweights for Plates ordered to thickness in widths from 120″ to, but not including, 132″. Overweights have no effect on Shell Material costs or Fabrication costs. It is not necessary to add overweights to Heads.
- All costs for Shells are expressed in dollars per lineal foot. The per lineal foot cost includes all Material and Fabrication costs.
- Pressure Vessel Shell lengths are usually designated as Tangent to Tangent. The Vessel Heads up to 1-1/2″ thick have been estimated with 1-1/2″ straight Flanges. Vessel Heads over 1-1/2″ thick have been estimated with 2″ straight Flanges. When Shell lengths are calculated as Tangent to Tangent deduct the straight Flange lengths of the Heads. When Shell Lengths are calculated as Head Seam to Head Seam do not deduct the straight Flange lengths of the Heads.
- Costs of Semi-Elliptical (SE) Heads include all Material and Fabrication costs. These heads may also be referred to as Flanged and Dished (F&D) Heads. The term “2:1” speaks to the ratio of the inside radius of the Head to the height of the ellipse.
- The costs shown do not include Nozzles, Manways, Skirts or other appurtenances. For Estimating costs complete with appurtenances
- PRESSURE VESSEL APPURTENANCES
After completing costs for Shells and Heads, it will be necessary to add for the following when required:
- Wear Plates and Saddles for Horizontal Vessels
- Angle Legs for Vertical Vessels
- Skirts For Vertical Vessels
- Threaded Coupling Type Nozzles
- Buttweld Flange Type Nozzles and Manways
- Long Weld Neck Type Nozzles and Manways
- Nozzle Extensions and Internal Piping
- Drip Legs
- Baffles, Drawoff Boxes, Vortex Breakers and Ladder Rungs
- Tray Rings For Removable Type Trays
- Installation of Removable Type Trays
- Installation of Demisting Pads
- Insulation Supports and Vacuum Stiffeners
- Ladder, Platform and Pipe Support Clips, Lifting Lugs and Davit Sockets
- Some Vessels may require fabricated items not specifically detailed in the foregoing and, if so, must be estimated and added:
- Removable Type Trays
- Demisting Pads
- PRESSURE VESSEL APPURTENANCES
- Costs are average for the United States at any port accross USGC
- Add See transtortation Freight to Country jobsite and all related expences for Custom duties.