Are Process Plant Designers Really that Sadistic?

Jan 29, 2024

Process Plants are not just an assembly of interconnecting pipes, vessels and equipment, they need to make space for the people who work and use them.

 

Don’t they?

A process design begins with the idea and then a pilot, and then the commercial reality.

 

At each stage there’s the excitement first of bringing the theory into practice and then scaling up so you can demonstrate it works, and then on to something that produces product for commercial purposes.

 

At that point is the risk that it all becomes a bit boring and functional, so the process designers are looking for their next fix of excitement.

 

But also at that point is the dependence of other people on that design for their jobs, products and profits. So where do they factor into the design?

Who’s Using the Plant?

Image shows a process plant room in a food factory with several stainless steel vessels, pipework above and pumps on ground level. The pump control stations are too high to reach.

On any process plant that I’ve visited, the operations team will moan that the designers used the wrong equipment, laid out the plant badly, made their (operators) lives difficult. In practice, it would be very rare or indeed sadistic, for any designer to wilfully make those sorts of decisions, although admittedly some considerations do seem a bit questionable!

 

On a day-to-day basis people will need to access and move around a process. For a partly manual process, this could involve moving ingredient product around and loading it. Even for significantly automated processes there is a need to check conditions, take measurements and readings (despite the use of SCADA across many plants, visual checks on instrumentation are still very popular – and necessary). In particular, an experienced process operator will be feeling the health of the process just by being present.

 

So why do we often find manual valves in places that can only be reached by a basketball player, instrument gauges that are placed upside down in a location that requires a qualification in potholing a torch and a good set of mirrors (don’t forget to invert the image you see!) and flooring that allows you to drop a small wrench down three storeys, but is adapted so that a group of 100mm pipelines running across at floor level have steps over them?

 

Every. Single. One.

Image showing water treatment membrane plant with horizontal membrane tubes, and housed in a plant room with people behind. Image shows the difficulty of access to high level equipment

Apologies to plant designers who do think about these matters – I salute you. However, these are realities I’ve encountered.

 

For a plant to be accessible by trained professionals like the operators, they need good lighting, instruments that can be read without having to resort to Pilates classes – remote displays can be useful, a safe method to charge product if necessary – and this shouldn’t include manually carrying 25kg bags up aircraft steps, and flooring, platforms and walkways that don’t change height at every opportunity and allow the operators to stand upright rather than continually stoop.

 

An operations health and safety risk assessment should pick these elements up, but it is better to deal with access at the design stage, rather than redesign your operations team.

Outside Visitors

Safety wisdom suggests visitors should be banned and not allowed on site!

 

Well, actually, it’s right to be proud of the plant and want the opportunity to show it off to people who aren’t familiar with it (and this can include senior management and investors), but outside visitors aren’t trained in the particulars of the process plant and to provide a full induction and training package for every party with and interest just wouldn’t be practicable.

 

So, in the process plant design, it’s a good idea to plan for visiting dignitaries to ensure:

 

  1. Smallest requirement for safety briefings or training
  2. Separation away from the plant so they don’t interfere with operations, so possibly no direct access to the plant
  3. Access flooring which feels more secure.
  4. Vantage points where the plant is visible, and briefings can be given.
Image shows a floor area with low roof and handrails with members of the public looking over a factory floor.

Visitors don’t usually want to get up close and personal with the process, but the sounds and heat can give them an experience to pass on to their own groups, so building in some form of gallery, if there is sufficient space, will keep the plant manager’s headaches to a minimum, and could also provide a platform (pardon the pun) for future generations to get enthused about the industry.

Who Put That There?

“Which thoughtful person put that there?”

 

..or more likely a slightly fruitier version of that, might be heard when maintaining the process plant.

 

In the design of the process and the layout of the equipment, many factors are taken into account, two of which are buildability and maintainability. So how come when maintenance is needed, accessibility problems aren’t that unusual?

Another factor is that sometimes replacement equipment isn’t exactly the same configuration as the original, but it does the same job. However, the arrangements to remove it or refit it may differ from the original design and will likely differ from the original maintenance documentation.

 

Of course, there is always the possibility that something was missed or not been checked which then causes grief to the maintenance team.

 

In the original design, it always pays to involve the operations and maintenance personnel so they can consider how they might support the plant and build that into the design before it’s built. If components need to change from the original design, let them have free rein to consider the accessibility and maintainability before putting them in, otherwise you may be learning a whole new lexicon of swearwords!

Images showing a dirty external process plant with vessels and inclined screw conveyors illustrating that later additions can restrict access for maintenance.

Mind the NIMBYs

Accessibility isn’t the only human factor to take into account. The aesthetics and environment are also important, not least to the people who are not involved in the plant but will have to live with it.

 

First up is smell.

 

Most industrial processes are usually sited in industrial zones with few residential properties around, although frequently there are other industries in the area and road. The smell that may be emitted by some parts of a process may be temporary, but with varying wind directions, could raise a stink for inhabitants in an unexpected area. Even odours which are often considered to be attractive, such as baking, can be obnoxious for some, especially when it is continually emitted. And the smell of cooking oil refinery can be particularly hard to swallow.

 

Secondly is the noise issue.

 

It’s an obvious matter, but can create problems with neighbours, regardless of whether you laid claim to your site before them. It’s one thing to generate noise in the execution of a process, which you can deal with for your own staff and visitors, but it’s something different when this goes outside your boundary. If, during process design, the use of the plant is properly considered, then there are ways of reducing that by acoustic enclosures, repositioning and sometimes even redesigning the process itself; after all, noise is wasted energy!

 

And thirdly the process design considers pollution.

 

The obvious part of that is pollutants from the process itself in the form of waste products, water discharge, and fumes. The process design team would have taken these into account as far as reasonable, so there are no unlawful discharges or compliance problems. These considerations are likely to cover most interactions with people.

 

But don’t forget the lights!

 

Having a process plant that shines with the intensity of a second sun next to a motorway network is bound to be at minimum a distraction and worse could be affect drivers’ vision, so while this brilliant lightshow might draw attention to your beautiful new shiny works, it isn’t exactly a welcome interaction to people passing by.

 

So, the key across all of this is to create a baseline assessment of the environment including odour, noise and light, and risk assess whether your process can co-exist with everyone else or if it would result in unwelcome human interaction.

Avoiding the Angst

Obviously, not every process plant design has embedded problems for the people who use, maintain and live with it, but by planning these considerations into the design from the outset, many issues can be avoided.

 

A well-design process plant needs to:

 

  • Enable the Operations team to access the measurements, controls and manual charging locations without risk of injury
  • Allow safe access to occasional visitors without interfering with operations.
  • Take account of unforeseen maintenance requirements without needing to make a drama.
  • Avoid involving the public, neighbouring businesses and residents in the operation of the process for negative reasons.
Image showing stack of lever arch files full of design documentation

Too obvious? Maybe, but also too often not obvious enough!

 

The design of the process is of course a high priority, but it is people who must work alongside it, so let’s make their lives easier.