Then and now; how pressure vessel manufacturing has advanced over the past 15 years

Then and now; how pressure vessel manufacturing has advanced over the past 15 years

9th September 2020

As a community of specialists, we are involved in highly complex projects and processes on a regular basis. With 2020 being our 15th anniversary, we would like to share some of our experiences of being involved in those projects, and provide an insight into the process of fabrication within pressure systems.

Modern pressure vessels are grouped into various categories, based on a range of criteria including intended use, material, and the procedures involved in their manufacture. These categories are the result of continued innovation, research, and development[1] and it could also be argued that these advancements have contributed to making manufacturing pressure systems a process associated with quality and safety at each level.

While it is almost impossible to have a one-size-fits-all blueprint for pressure vessel design and fabrication, vital considerations have been made which all need to be recognised during these processes. This has been the result of ongoing research and technological developments, as well as the ability to find cost-effective solutions to end-user requirements.

To give a generic, overall view, these are just some of the aspects that vessel designers must be mindful of[2]:

  • Dimensions
  • Operating Conditions
  • Available materials in the market
  • Corrosive nature of vessel contents
  • Theories of failure
  • Construction methods
  • Methods of fabrication
  • Metal fatigue
  • Economic consideration

It is imperative that critical guidelines pertaining to quality assurance are not only followed but engrained into the heart of any organisation within the field. Whilst each country has its own variations, over the course of history, critical marks of accreditations have been established and accepted across the pressure sector.

Different quality marks invariably mean adopting a slightly different approach in a structure’s fabrication. There is now an array of methods used within the same process – they are not necessarily ‘wrong’, merely that alternative ways of bringing a pressure system together are being explored and accredited where appropriate.

Whilst these marks have been key to maintaining safety and quality worldwide, there is always room for continued improvement. Fabricators, for example, can take elements of accreditation such as ISO and EN marks, and routinely assess their operation against these benchmarks.

This level of intense self-analysis breeds a culture of safety at an organisation, supported by strict guidelines to hold it accountable to a safe way of working. Understanding that there is more to safety and quality than simply ticking boxes is also a means of identifying where improvements can be made.

Particular areas of focus pertaining to fabrication include but are not limited to:

  • Forging, casting and fabrication processes including their effect on properties
  • Emergent manufacturing processes, HIP, etc.
  • Welding
  • Heat treatment and stress relief
  • Proof testing

A final but no less important change observed over the years has been the overall role that pressure systems, fabricators, and engineers have in today’s society. A demand for less harmful sources of energy, stored in vessels built for longevity and with as little expense as possible, is resulting in a continually collaborative process between different markets, each needing to meet individual requirements but still working towards the same end goal, as we have experienced through our work with ITM Power last year.

Our expertise in metallurgical testing – a process continuing to emerge and develop within the pressure systems manufacturing space – and minimising the risk of corrosion led us to suggest stainless steel as the most suitable material to use in ITM’s hydrogen storage tanks; a decision which would mean longer term cost savings while retaining safety levels.

Sharing knowledge and expertise in this way will ultimately allow the pressure systems sector to continue on an upward trajectory. We as an industry are constantly looking for ways to improve, embracing new technologies and methods, all of which are essential if we are to maximise our future potential.

[2]https://www.researchgate.net/publication/330423928_A_critical_review_and_analysis_of_pressure_vessel_structures/link/5c3f678c458515a4c72a83a7/download