ASME Code Pressure Vessel Design

ASME codes are used for pressurized equipment – vessels, piping and fittings – in North America and many other countries. ASME codes cover the design, construction, maintenance and alteration of pressurized equipment. Most commonly used ASME codes are:

  • VIII-1 for vessels, towers and exchangers
  • I and IV for boilers and hot water heaters
  • B31.1, B31.3 and B31.5 for piping systems
  • B31.3 is also used for many fittings

These are design by rules codes which provide formula methods that work if the design falls clearly within the scope of the code.

For more complex or unusual designs, ASME VIII-2 rules based on design by analysis is used in conjunction with Finite Element Analysis (FEA) tools. This is discussed in the FEA Stress Analysis section.

ASME Samples

These are our most popular samples – from a companies first audit vessel, simple vertical and horizontal vessels, to a more complex heat exchanger. Design calculations and shop floor drawings are discussed. More samples can be found in the ASME Blog.

Audit Vessel

This is a typical audit vessel used for first time ASME VIII-1 audits, or when no in-production vessel can be used. Calculation verification, what happens during an ASME audit and how many sample vessels need to be built to justify more than one ASME stamp are discussed.

Water Softener Vessel

This water softener is typical of many we have designed for drinking water or industrial use. The use of Compress, IBC Seismic calculations, and using SolidWorks for vessel drawing is discussed.

Horizontal Retention Vessel

This 8ft diameter contact tank (or retention vessel) keeps water and chlorine in contact for a guaranteed minimum safe amount of time at the maximum possible flow rate. Saddle design is discussed.

Heat Exchanger

This sample heat exchanger is a collaboration with H&C Heat Transfer Solutions who ran the heat transfer calculations. The sample includes a brief discussion of UHX design, PV Elite code calculation software and using SolidWorks for drawings.

ASME Articles

Our most popular articles. Why is it harder to design a vessel for external (vacuum) pressure than internal pressure? When do design by rules need to be replaced by Finite Element Analysis (FEA) for reliability – in this case for an obround nozzle? How wind and seismic loads affect the shell thickness of a tower, and how to choose between different head types. More articles can be found in the ASME Blog.

External Pressure

External pressure (vacuum) calculations are more complex than internal pressure calculations. Once jackets or other sources of pressure are added the difficulty increases. What affects the external pressure rating and the failure mechanisms are discussed.

Designing Trouble-Free Large Obround Nozzles

ASME VIII-1 Code provides the required rules to design obround nozzles, but it also takes FEA to design a trouble free obround nozzle that does not leak.

Buckling of Dished Heads

ASME VIII-2 contains three analysis types to assess collapse from buckling. Per ASME VIII-2 article (a) Type 1- If a bifurcation buckling analysis is performed using an elastic stress analysis without geometric nonlinearities in the solution to determine the pre-stress in the component, a minimum design factor of ΦB = 2/ ßcr shall be…

Tower with Wind, Seismic and Vacuum Loads

This tower is designed for a combination of seismic, wind and external pressure (vacuum) loads. The calculations are done in Compress, and the drawing is made in SolidWorks. Which loads govern and how to support junctions is discussed.

Comparison Between Head Types: Hemi, SE, F&D and Flat

We compare the required thickness of Hemispherical (Hemi), Semi Elliptical (SE), Flanged and Dished (F&D) and Flat heads using the rules of VIII-1 and VIII-2 FEA.


This blog has more samples and articles, design guides and discussions related to ASME codes.

ASME Methods Blog

Samples, articles and guides for the design and modeling of ASME pressure vessels.

ASME Code Design at PVEng

We work to many ASME standards to design and validate pressure vessels, boiler, fittings and piping systems. We have experience designing thousands of vessels and fittings to multiple codes.

  • Pressure vessel design to ASME VIII-1 and VIII-2
  • Hot water heaters and boilers to ASME I and IV
  • Piping to B31.1, B31.3, B31.5 and others
  • Burst testing to multiple codes

We use Compress, PV Elite, Design Calcs, Nozzle Pro and our own in-house software.

Other Services

Finite Element Analysis (FEA) – We use FEA to design and validate fittings and vessels that cannot be designed by rule-based codes like VIII-1 or B31.3.

Pipe Stress Analysis – Pipe stress analysis is mandatory for British Columbia registration and it is recommended practice for many other systems.

Canadian Registration Number (CRN)We are Canada’s largest independent registrar of fittings, vessels and piping under the CRN program registering for more than a thousand customers.

About Us

Pressure Vessel Engineering has over twenty years of successful experience in the pressure vessel field working for more than a thousand customers.

  • Twelve Professional Engineers on staff licensed to stamp and sign off on designs for use in all Canadian jurisdictions.
  • Fast and professional assistance from our team.

Need help? Our contact information is to the right.