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Expansion Supports

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Subcon designed and patented X-Mat provides an elegant solution to providing low friction supports for Z- spools and pipelines where thermal expansion can be expected. X-Mat is a high performance concrete mattress with a continuous HDPE surface for low friction, abrasion free sliding.

It’s ultra low profile mean freespans do not occur at the touchdown points. They also occupy minimal deck space when compared with conventional methods like sleeper supports. This reduces the cost of installation and maintenance.


Subcon has deployed X-Mats on multiple projects to great success.

Their reduced vessel back deck footprint (compared to sleepers) provides significant savings to the total installed cost of the support.

While the X-Mat does not provide buckle initiation for the pipeline, it provides a sliding surface with a known friction coefficient that assists pipeline designers with buckle design and ensures the pipeline will buckle as it is intended to.

X-Mat allows designers to guarantee expansion and buckling will occur as designed and that the pipeline will not be overstressed due to burial.

X-Mat uses HDPE moulds that is part of the final product. As a solution for spool supports, there is no complex steel formwork or reinforcement bars like found in sleepers. This lends itself to being deployed in remote or low-skilled environments.

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