THE EFFECT OF LOCATION ON PRESSURE VESSEL DESIGN
Pressure vessels are installed in many different settings, owing to their demand in a variety of industries, including manufacturing, research, power generation, oil & gas, and storage among many others. Pressure vessels despite their robust construction, can be very sensitive to environmental factors arising from location. It is imperative that pressure vessel manufacturers and owners are aware of the site environmental and physical conditions and take these into consideration during the design phase. Occasionally a pressure vessel might be relocated and as far as possible the new environmental and physical situation must be assessed.
Pressure vessels are installed in many different settings, owing to their demand in a variety of industries, including manufacturing, research, power generation, oil & gas, and storage among many others. Pressure vessels despite their robust construction, can be very sensitive to environmental factors arising from location. It is imperative that pressure vessel manufacturers and owners are aware of the site environmental and physical conditions and take these into consideration during the design phase. Occasionally a pressure vessel might be relocated and as far as possible the new environmental and physical situation must be assessed.
UNDERSTANDING THE EFFECT OF LOCATION
The location of installation for a pressure vessel is, thus, critical in successful pressure vessel design. Manufacturers usually research certain measurements about the conditions of the location, obtaining such site data as rainfall, wind severity, seismic activity in the region, snow load, etc. The larger the vessel, generally the greater the influence of the physical conditions; for instance a 20 metre column will be more severely affected by wind than a small diameter horizontal vessel.
Disregarding the effects of location on operation can result in the making of an under-strength pressure vessel that may break down when the conditions change significantly due to any temporary event or trigger.
There are other environmental factors which may impact on the design of the vessel, its finishing such as painting or other coating, the material thickness and more basically the choice of material of construction. Vessels in marine or estuarine environments will be subject to chloride attack and materials such as duplex or super duplex stainless steels are often considered. In many industrial, chemical and petrochemical sites there can be varied environmental conditions which will have a bearing on the design of the pressure vessel. Some considerations include thermal ranges, presence of potentially corrosive gases e.g. hydrogen sulphide.
PRESSURE VESSEL RELOCATION
For any number of reasons, a vessel may need to be moved to a new location with different conditions than it dealt with before. Plant owners often revise their premises plans or transform into bigger plants due to expansion. In such situations, assets are displaced and equipment is relocated. The physical process of relocating a large pressure vessel is a logistical challenge in itself – but the potential change in external conditions between the locations and while in transit are also important.
Even fairly subtle differences in site conditions have the potential to affect operation and lead to extensive damage to the vessel itself, the equipment and property around the vessel, and to any personnel working in the close range. Close consideration should therefore be given to working tolerances in advance if it is considered likely that a vessel will need to be relocated.
Similarly, insufficient planning when relocating a vessel can also result in disaster. It should be mentioned that relocation does not necessarily involve shipping the plant to new premises across the country, or the sea, where it has to deal with very different conditions. It may in fact simply be relocated within the same plant, from an indoor to an outdoor environment, for example. In such cases, problems with the pressure vessel’s integrity arise due to inadequate reinstallation, leading to a compromised system ready to fail under testing situations.
For a pressure vessel engineer, understanding the importance of location is important whether it is a new vessel that is in question or an existing vessel that needs relocating.