The First Shrink-Fit Riser Flanges

Subsea Riser Products (SRP), an Acteon company, has successfully attached the first flanges to pipe sections that will make up a unique ultra-high-pressure drilling riser for use by Venture Production in the North Sea. The flanges were joined to the pipes at SRP’s premises in Sheffield, UK, using a novel shrink-fit process that the company developed specifically with the fabrication of risers like this one in mind.

SRP managing director Simon Luffrum said, “The development of the shrink-fit flange has been the key to this entire project. We have had a good deal of interest in the technique from a number of other operators. Now that we have proved the technique it is likely to find application in a variety of riser-related projects in the future.”

The flange is first heated using induction coils to over 400°C, which causes it to expand sufficiently to fit over the end of the 19¼-in ID riser pipe section. The flange and the pipe are then carefully brought together – this part of the process takes no more than 30 seconds – using a purpose-built jig to ensure the precise alignment of the two parts. Simply allowing the assembly to cool down creates a high-quality structural connection and a gas-tight seal.