If the basic idea of using ASME Pressure Vessel Software for cost-effective Pressure Vessel design and manufacture is to safely and quickly answer the question, “how thin can I get with a certain material, while still being safe?” There's always an element of compromise in the process. Safe is not a binary. It's relative. That's why there's a safety factor built into the ASME Section 8 code.
When is thin too thin and who decides?
You don't want a designer under pressure from a business owner, deciding to make an exception on a minimum wall thickness beyond generally accepted standards. You need something external to ensure that decisions are consistent across the entire industry, and enforced with an Inspection program that deters temptation to waiver from the code.
In most cases, the person elected to do this work, a designer or a professional engineer, typically understands and accepts this regulated position. The more knowledgeable designer or engineer typically wants oversight from someone external to the business, or access to a commercially available product in general use by other companies in the same field.
A key decision component of investing in a commercially supported software application will be the requirement for the engineer to understand how the ASME pressure vessel software performs the calculations. Transparent formulas and calculations enable the added benefit of an external resource to consult when the designer or business owner is required to make design optimization decisions for cost and safety. This external validation of decisions can protect businesses from the potential conflict of interests described earlier. The decisions can also be made with confidence knowing that verifiable calculations are kept current by an external entity, with proven testing protocols that maximize your ASME code compliance.
Are you working with multiple codes in a single design?
Requirements for multiple codes come into play far more often than people realize. The basic pressure envelope, will have calculations that are well defined in the code so that you have a given safety factor, but the vessels don't float! You must support the vessels with something, and the current code that's still used in most cases in the United States for pressure vessels is the Section 8, Div 1.
The code has limited information, relating to support structures, so, in every case, a designer must select a vessel support option, i.e. a leg, a lug, a skirt, a saddle, etc. At the point where that interfaces with the vessel, you have a meeting of the pressure vessel code, and for example the wind and seismic codes.
Designers can be forced to make decisions that are not explicitly stated in a single code. In these cases, the designer must use sections of code, and fully understand the implications of how codes interact to be able to make the correct decisions to achieve a safe vessel wall thickness. Factors to be considered are not just for pressure, internal or external, but also requirements to satisfy the load for that vessel or the components attached to the vessel.
An Authorized Inspector perspective?
Moving beyond the pressure vessel design process brings the discussion to where it is to be manufactured and where the authorized inspector will then sign-off on the stamp. I think it is fair to say, that if the Inspector identifies that someone is performing hand calculations, or doing something that they made themselves in Excel, it may raise a red flag.
Authorized Inspectors require that the basis of design calculation used is compliant and proven, which can be more challenging to justify with homegrown tools. Inspectors are typically far more comfortable with a market-proven commercially supported ASME pressure vessel software when compared to a home developed Excel spreadsheet macro.
Even if you've been using that calculation for five years or ten years, they don't know for certain that the Excel spreadsheet didn't change. Perhaps, in their mind, they are questioning if you tweaked something in the math so that you can get away with a thinner vessel than you really should?
So, the perceived cost saving by not using a commercially supported ASME Pressure Vessel Software can result in extra costs or delays associated with the Inspection process.
Our clients can trust that with over 1000 companies using our software solutions, they are field proven and experienced in applying generally accepted best practices. Our experience combined with our continued investment in attending code meetings and staying current is why DesignCalcs is the industry-leading ASME Pressure Vessel Software. Being aware of the intent behind the code, not just the letter of the code are important factors as to why users have confidence selecting DesignCalcs from CEI.
If you’d like to put DesignCalcs through its paces, simply hit the following button to click here to request your free DesignCalcs activation of a trial license…
You can, of course, call us or contact us through the website, where we’d welcome the opportunity to answer any questions you may have on this post.