Comparative study of Pressure Vessel Design Software – Case Study for Vertical Column

Objective
The purpose of this study is to perform a detailed comparison of pressure vessel design workflows using two different software tools – VCLAVIS and a leading industry-standard software (latest available as of April 2025). The focus is specifically on the design of tall vertical vessels (columns), which involve endurance to wind or seismic loads, as outlined in the ASME VIII DIV.1 standard for unfired pressure vessels.

Designing a vertical column presents unique challenges, such as the need to evaluate the equipment behavior in wind or seismic, assess the principal stresses and incorporate complex stability scenarios. The column typically is equipped with ladders and platforms, insulation and fireproofing at the skirt. Hence modeling the column on software is challenging and leads to increased engineering hours, the need for auxiliary spreadsheets, and manual intervention in conventional software environments.

This study assesses how each software handles:

• Detail of input such as platforms, ladders e.t.c
• WRC analysis
• Stability analysis
• Workflow automation and report generation

By executing the same design scenario on both software, the study quantifies the time required for each task and identifies bottlenecks or inefficiencies. The ultimate goal is to evaluate not only time savings but also the robustness and user-friendliness of the tools involved in pressure vessel design under demanding analysis conditions.

Sample vessel specifications
Cylindrical vessel with two elliptical heads ASME 2:1 supported on cylindrical skirt, equipped with trunions and tailing lug to facilitate lifting, bearing two platforms on the shell and a connecting ladder. The column needs to be evaluated per TECHNIP JSD-0400-001 design load cases. Column nozzles need WRC analysis based on TECHNIP specifications. The following technical characteristics apply:

Design Data
Internal Design Pressure:	1 MPa
Internal Design Temperature:	250°C
External Design Pressure:	0.1 Mpa
External Design Temperature:	250°C
Corrosion Allowance:	1 mm

Dimensional Data
Component	Diameter	Thickness	Length	Material
Shell1	OD=1500	T=20	L=5000	ASME II: SA516-70
Shell2	OD=1500	T=18	L=5000	ASME II: SA516-70
Shell3	OD=1500	T=16	L=5000	ASME II: SA516-70
Shell4	OD=1500	T=16	L=5000	ASME II: SA516-70
Top Head	OD=1500	T=16 (af)	sf = 50	ASME II: SA516-70
Bottom Head	OD=1500	T=20 (af)	sf = 50	ASME II: SA516-70
Skirt	OD=1500	T=10	L=2000	ASME II: SA516-70

Example Nozzle Index (Nozzles with Pads)
Tag	Description	Dimension	Make	Nozzle material	Flange Rating	Flange material
1M	Manway	DN600	Plate 16mm	ASME II: SA516-70	300#	ASME II: SA105
2M	Manway	DN600	Plate 16mm	ASME II: SA516-70	300#	ASME II: SA105
1N	Inlet	DN200	Pipe 12.7mm	ASME II: SA106-B	300#	ASME II: SA105
2N	Outlet	DN200	Pipe 12.7mm	ASME II: SA106-B	300#	ASME II: SA105
3N	Drain	DN50	Pipe 8.74mm	ASME II: SA106-B	300#	ASME II: SA105
4N	Vent	DN50	Pipe 8.74mm	ASME II: SA106-B	300#	ASME II: SA105

Platform and Ladder index
Tag	Dimension	Self weight	Live Loads
P1	Ri = 800, Ro = 2000, H = 1100, span 180°	150 Kg/m²	250 Kg/m²
P2	Ri = 800, Ro = 2000, H = 1100, span 180°	150 Kg/m²	250 Kg/m²
L1	Width 400mm, wind 0.4m²/m	40 Kg/m	N/A

Design Execution Time: Industry Software vs. VCLAVIS
Industry software (2025 edition)
Examination Point		Time	Issues spotted
1	Model primary components	10 min	No problems spotted
2	Model nozzles	20 min	Typically 5 min per nozzle
3	Perform WRC analysis	20 min	Software does not have Technip Local Loads Libraries
4	Model platforms and ladder	10 min	No problems spotted
5	Model wind for platforms and ladder	10 min	The software does not account ladder wind. User needs to calculate ladder wind area and implement it on the vessel as diametral increase
6	Model live loads on platforms	20 min	The software can’t account for platform live loads. User needs to calculate the platform live loads on a separate spreadsheet and enter them as “forces” on the main column.
7	Model and check wind	20 min	Take time to check if wind is handled correctly
8	Model and check seismic	20 min	Take time to check if seismic is handled correctly
9	Assign JSD-0400-001 stability scenarios	45 min	Not readily available in software, user needs to open the specifications and manually set the software scenarios. Live loads need to be implemented separately.
10	Design for each stability case	45 min	User needs to prepare separate files for each scenario in order to verify the skirt component and the skirt to head junction, since only operation (worst of seismic or wind) and test is presented.
11	Design trunions and tailing lug	40 min	There is no check of the tailing lug interaction with the skirt base ring. A dedicated spreadsheet is required per Denis R. Moss procedures.
12	Perform rigging analysis	10 min	No problems spotted
13	Time to print final report	30 min	Delay is spotted in order to merge reports from various files into a single engineering report.
Aggregate time:			300 min (5 hrs)

Design Execution Time: Industry Software vs. VCLAVIS
VCLAVIS
Examination Point		Time	Solutions adopted
1	Model primary components	10 min
2	Model nozzles	20 min
3	Perform WRC analysis	10 min	Built in Technip Local Loads Libraries, calculations automated within nozzle modeling.
4	Model platforms and ladder	10 min
5	Model wind for platforms and ladder	0 min	Ladder wind is considered automatically on ladder modeling
6	Model live loads on platforms	0 min	Live loads are considered per load case and input in platform GUI
7	Model and check wind	20 min	Take time to check if wind is handled correctly
8	Model and check seismic	20 min	Take time to check if seismic is handled correctly
9	Assign JSD-0400-001 stability scenarios	10min	Readily available as “Classic Pressure Vessel Stability Cases”
10	Design for each stability case	15min	Vessel stability checks are automatically produced, but it takes some computing time to run and check all scenarios at once. However user does not need to perform any actions.
11	Design trunions and tailing lug	15 min	Readily available Denis R. Moss procedures
12	Perform rigging analysis	10 min
13	Time to print final report	10 min	It takes some time printing all output into pdf final report and merging summary and calculations reports. However user does not need to perform any actions.
Aggregate time:			150 min (2.5 hrs)

Results

The comparative analysis reveals a significant efficiency gap between the two software tools. Traditional industry software, while capable, necessitates considerable manual effort, including the use of auxiliary spreadsheets, manual code checks, and separate analyses for each stability scenario. In contrast, VCLAVIS streamlines the process with built-in capabilities for stability analysis, and automated reporting. By reducing the total design time from 5 hours to just 2.5 hours – a 50% reduction—VCLAVIS Software for Pressure Vessel Design demonstrates its superiority in both speed and usability. These savings are not merely time-related; they also reduce the chance of user error, standardize compliance procedures, and free up valuable engineering resources for higher-level analysis and optimization.

In high-demand engineering environments where accuracy, speed, and compliance are non-negotiable, adopting a robust and modern tool like VCLAVIS is not just beneficial – it’s strategic.

Author: Dassa Isaak

Co-Founder & Lead Engineer at VCLAVIS O.E. Experienced Mechanical Engineer with a strong track record in the pressure vessel industry, specializing in the design and analysis of heat exchangers. Proficient in leading engineering tools including VCLAVIS.com, Autodesk Inventor, PVElite, VVD Ohmtech, and HTRI. Highly knowledgeable in international design codes and standards, including ASME, AD2000, PD5500, and EN13445. Holds a Master’s degree in Mechanical Engineering from the Aristotle University of Thessaloniki. Lead Engineer and Co-Founder of VCLAVIS.com, a specialized software platform for pressure vessel calculations.