ECE has been engaging the Pressure Vessel Analysis Community on the Workflows with PV Elite over the past few years. In this blog post I would like to bring that information back to the industry, by detailing the top issues that I have come across to date. To assist my answers in this post I recently sat down with the technical director of PV Elite for Intergraph, to get a larger perspective on the issues surrounding these questions and how we can better implement upcoming changes to the software. The following are the top issues and responses to those issues:
- Is PV Elite tied to a beam solver? – Yes, for Natural Frequency and Response Spectrum Calculations.
- Where is the option for a field hydrotest value? UG-99(c) is an option available with the other test options, vertical or horizontal test can also be specified.
- Is there a way of modifying the factor for membrane stresses, in the WRC 107 local stress analysis for a nozzle? Not directly, but we have options for using stress indices as well as Kn and Kb.
- What is the screening criteria for vortex shedding? The vibration possibility is a function of the weight, height and diameter of the vessel.
- How are lugs supported when they are added to a vessel? Lugs are assumed to be bolted to the attaching structure.
- Does a WRC 107 calculation in PV Elite include pressure thrust? This is optional.
- What criteria is used to evaluate holes in skirts? This analysis is per EN-13445.
- What default parameters are used to define lifting lugs? The default parameters are simply hard coded into the software.
- What is the method used to do a WRC 107 calculation on an elliptical head? Based on the head diameter an equivalent spherical diameter is computed.
- What methodology is used to find wind loads on platforms? The area is based on 1 of 4 methods that are commonly used by large E&C companies. The basic force then becomes the pressure times the area.
- When you have two sets of lugs, upper lug calculations don’t show up? PV Elite only solves for the loads on the first set of lugs. 2 sets makes for a statically indeterminate problem.
- Why does acceleration occur on lug supported vessels? How are the lugs being supported? Something has to accelerate during an earthquake. In our analysis the vessel accelerates around the supports.
- Can we use STS-1 for the ASME Steel Stack Analysis? Yes, for cylindrical stacks.
Regards,
George Montgomery
gmontgomery@ecedesign.com
