AutoPIPE - Error Code 21 - EXTERNAL PRESSURE (Section No. XXX) (in operation): section (Element of cone) does n

Introduction

The following message appears in AutoPIPE Vessel, how to avoid it?

21 EXTERNAL PRESSURE (Section No. XXX) (in operation): section (Element of cone) does not meet the required external pressure. Recommend increase thickness or add stiffener along design length.

Instructions

According to the error message, cone section does not meet the required external pressure criteria. Please open the complete report and click on the hyperlink text to navigate to the relevant section of the report.

Avoidance:

F_L is a negative number, the design shall be in accordance with U-2(g)(Code Case 2695 could be an option).
Increase thickness or add stiffener along design length.