Modular process skid

A modular process skid is a process system contained within a frame that allows the process system to be easily transported. Individual skids can contain complete process systems and multiple process skids can be combined to create larger process systems or entire portable plants. They are sometimes called “a system in a box.” An example of a multi-skid process system might include a raw materials skid, a utilities skid and a processing unit which work in tandem.

Process skids are considered an alternative to traditional stick-built construction where process system parts are shipped individually and installed incrementally at the manufacturing site.^[1] They provide the advantage of parallel construction, where process systems are built off-site in a fabrication facility while civil site upgrades are completed at the plant site simultaneously.^[2] Skids are not always appropriate. If individual process parts are large and cannot reasonably be contained within the frame of a modular process skid, traditional construction methods are preferred.

Skid design and layout

Process skids are designed to contain a complete process system, a complete unit of operations or to organize a manufacturing process into logical units.^[3] All skids have the following characteristics in common:

Portable design– because they are self-contained units, built within frames, skid systems are easier to transport than traditional process systems.
Small footprint – process skid frames allow equipment layering. Piping, tanks, and necessary process equipment can be fit into a smaller footprint with a skid design
Gathered process connections – process connections are gathered into one spot on the skid, making plant connections easier. In traditional process systems, connections are spread throughout the plant.
Controlled assembly – skids are typically built in controlled conditions offsite. Existing operations are not affected by skid fabrication.
FAT testing before installation – Factory acceptance testing (FAT) can be completed before modular process skids are shipped to site. This reduces the amount of on-site startup time.
Accessible layout – skids are designed for accessibility, usually including a center hallway, and major pieces of equipment placed around the edge of the frame.

Advantages of a skid process system

Skid process systems provide a plethora of advantages to traditional stick built construction process systems. The main advantage is quality control. Because only one party will be responsible for the construction and build of the skid process unit, there is a higher level of responsibility and quality control. With stick build methods of construction, there are many different levels of building before the final process unit is complete, making it difficult to determine which party is responsible for an error. Skid process systems are fully tested before being sent out; therefore they are ready to be used immediately upon delivery. Lastly, the skid process system allows for efficient use of space. A skid process system fits into a set frame; meaning space is efficiently used to house all of the parts of the process system, and the skid process system can be moved to another location if it ever becomes necessary.^[4]