Equipment Damage Mitigation
Blast damage to large plant equipment (vessels, distillation columns, tanks, etc.) can result in significant release of flammable/toxic inventories and possibly cause fires, explosions, or hazardous releases. Furthermore, structural failure of some of the pipe rack components, including the pipes themselves, can result in domino effects and further escalate an already dangerous situation.
The objective of a structural analysis is primarily assessing the blast damage to the components of interest, and estimating the consequences of the calculated damage. The structural assessment must distinguish not only the modes of failure for key components, but also the damage levels associated with consequences of importance.
Typical components of interest are the elements of the pipe rack structure, which can be categorized into primary and secondary elements, and the pipes, as illustrated in Figure 1.
Figure 1. Pipe Rack Structure and Equipment Components
BakerRisk’s approach to estimating blast damage to pipe racks and other important plant equipment and their supports is to perform simplified dynamic analyses of individual key elements. The dynamic analyses allow not only taking into account the transient nature of the blast load, but also the interaction of the pressure wave with the structural elements.
Damage Categorization
The main categories of damage that could result in significant consequences are summarized below:
- Pipe support damage (pipe rack component damage)
- Damage to main pipe supports such as pipe rack columns and some of their bracing members, as shown in Figure 2 and Figure 3
- Damage to secondary supports such as pipe brackets and secondary pipe rack beams as shown in Figure 4
- Pipe blast damage from bending, flange failure, or from significant shifting along the pipe rack, as shown in Figure 5
- Pipe debris damage caused by objects falling on or impacting the pipes, as shown in Figure 6
Figure 2. Main Support Foundation Damage (Concrete Column)
Figure 3. Main Support Foundation Damage (Steel Column)
Figure 4. Pipe Shifting and Bending Without Loss of Containment
Figure 5. Vessel Sliding Off Supports
Figure 6. Pipe Rack Damaged by Debris
The damage modes summarized above can have various levels of severity ranging from minor damage to catastrophic. BakerRisk carries out a categorization of damage to assess the consequences to the equipment itself and to the loss of containment of materials being transported.
