UG-98, MAWP and Liquid Static Head CalculationsPaul Daniel2019-03-14T13:58:44-04:00
UG-98 MAWP, Liquid Static Head and Pressure Vessel Design
Most process vessels contain operating fluids which produce liquid static head that must be accounted for when determining the design pressure P. Paragraph UG-98 of the ASME® Code also requires that static liquid head be deducted when determining a pressure vessel’s maximum allowable working pressure or MAWP. As the pressure due to liquid static head varies based on each individual component’s elevation, complying with this seemingly simple requirement quickly becomes a time consuming task. The COMPRESS Automatic Liquid Level feature saves time and reduces errors by eliminating the need to manually calculate the location specific static head for every nozzle, flange, shell course and head situated below the normal operating liquid level (NLL). Similarly, COMPRESS automatically deducts the correct local static head from each component’s UG-98 MAWP when determining the overall vessel’s rated MAWP. This powerful feature has the added benefit of supporting multiple pressure chamber designs. In this case, a separate liquid level and specific gravity may be specified for each vessel chamber.
Changes made to a liquid level in COMPRESS automatically flow through all affected aspects of the pressure vessel’s design and UG-98 rating. In addition to re-calculating component static liquid heads, moving the liquid level or changing the specific gravity causes COMPRESS to update overhead weights, foundation loads and the period of vibration calculation.
A new feature that speeds up the process of pressure vessel modeling.
Software packages like COMPRESS exist to increase productivity and save Engineering hours.
Perform ASME UHX and TEMA calculations and transfers these designs to your estimating and drafting departments.
Many companies use the alternative rules of Division 2 because of the cost savings, versus Division 1.
MDMT Rules of UCS-66
The rules of UCS-66 guard against vessel failure by brittle fracture, a low probability high consequence event.
Pressure vessel FEA is more accurate than the methods of WRC-107, WRC-297 or WRC-537.
The Vessel Wizard speeds pressure vessel design by creating complete pressure vessel models with minimal input.
Import files from COMPRESS and create user customizable pressure vessel cost estimates in spreadsheet format.
Create optimized Appendix 2 (custom or body) flange designs with minimal time and effort.
Designers can visually confirm good practices such as staggered longitudinal seams.
Lifting & Rigging
Use an accurate weight, the correct center of gravity, and apply the actual section properties.
Modeling + Drawings
The Codeware Interface includes Drafter 3D, a feature that auto-generates 2D pressure vessel drawings.
COMPRESS implements a wide range of related engineering methods, codes and standards.
Save time by reducing the trial and error iterations that would otherwise be required when designing pressure vessels.
Rating (Analysis) Mode
The COMPRESS Rating Mode takes your design and determines the vessel’s MAWP, MAEP and MDMT.
Performing hydrotest stress calculations in the design stage prevents equipment damage during hydrotesting.
COMPRESS saves time by calculating chord openings and governing planes of reinforcement automatically.
Older ASME Codes are retained in all COMPRESS releases so you can always use the latest software.
Automatic Liquid Levels
COMPRESS eliminates the need to manually calculate each vessel component’s liquid static head.
Global External Loads
The Loads Menu allows designers to easily consider global external loads when sizing pressure vessel supports.
Clips and Lugs
Designers can quickly include the mechanical effects of pressure vessel internals and attachments in their designs.
Certain industrial processes require pressure vessels with multiple chambers operating under different design conditions.
Produce more economical Div 1 pressure vessel designs with increased accuracy from the Div 2 design by rule equations.
Manufacturer's Data Reports
Simplify the creation, submission and management of ASME Manufacturer’s Data Reports and NBIC Repair and Alteration Forms.
Support Skirt Openings
Specify piping connections to vertical vessels that require additional piping and openings cut out of the support skirt.
Foundation Loads Summary
Break down the loads for the specified vessel operating conditions including weight, wind, seismic, and vortex shedding.
UG-80 and UG-81
COMPRESS automatically provides out-of-roundness tolerances that must be maintained during pressure vessel fabrication.