Inventor parametric modeling interface
Fig 1. Parametric model of pressure vessel nozzle with iLogic controls

After implementing parametric modeling and iLogic in our pressure vessel design workflow, we reduced repetitive modeling tasks by 50%. This article shares the exact techniques that helped us achieve ASME compliance while maintaining flexibility for custom client requirements.

Key Benefits:

  • Generate 90% of standard vessel variants from one master model
  • Automate ASME Section VIII compliance checks with iLogic
  • Reduce design iteration time from hours to minutes

CAD Modeling Best Practices

Proper CAD techniques directly impact compliance documentation. Here are my top Inventor techniques for pressure vessel design:

Parameter Organization Framework

Vessel_Geometry
  • OD_mm = 1200
  • Length_mm = 3000
  • Thickness_mm = (P*R)/(S*E-0.6P)
Nozzle_Details
  • N1_OD_mm = 150
  • N1_Location_deg = 45
  • N1_Thickness_mm = Thickness_mm * 1.2
ASME_Requirements
  • Min_Thickness_mm = UG-16(b)(4)
  • Corrosion_Allowance_mm = 3.2

Critical Design Rule:

Nozzle spacing ≥ max(3×Nozzle_OD, 150mm)

ASME Section VIII, UW-13

iLogic Automation Techniques

These iLogic scripts transformed our workflow:

A. Automatic ASME Compliance Checker

ASME Thickness Checker 
' Validate against UG-16(b)
If Thickness < Min_Thickness Then
    MessageBox.Show("UG-16(b) violation", _
                    "ASME Compliance", _
                    MessageBoxButtons.OK)
    Thickness = Min_Thickness * 1.1
End If

' Check nozzle reinforcement per UG-37
If Nozzle_OD > 0.5 * Shell_ID Then
    If Reinforcement_Area < Required_Area Then
        MessageBox.Show("UG-37 Violation: Add repad or increase thickness", 
                        "ASME Compliance Error", 
                        MessageBoxButtons.OK)
    End If
End If
Press F5 in Inventor to test

This script auto-populates drawing templates based on model parameters:

  1. Extracts material specs from iProperties
  2. Generates BOM with ASME required columns
  3. Applies correct revision cloud based on change log

B. Drawing Template Automation

Free Resource: iLogic Starter Kit

Pressure Vessel Automation Toolkit

Includes:

  • 3 ready-to-use iLogic scripts
  • ASME compliance checker module
  • Parameter naming convention guide
Download Now (ZIP, 4.0KB)

Final Recommendations

From implementing these techniques across 30+ vessel designs:

Start small: Automate one repetitive task each week. Within 3 months, you'll build a powerful automation library.

Have specific Inventor challenges? Contact me for personalized advice.

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