Nu-Bolt™ assembly – InnoCorr Offshore

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Prevent crevice corrosion at pipe supports

Nu-Bolt™ Assembly

Nu-Bolt assemblies have been in service for over 20 years without a single reported failure.

Designed by corrosion engineers, the Nu-Bolt assembly combines the half-round I-Rod support with a modified pipe U-bolt. A variety of corrosion-resistant treatments provide reliable, long-term service in the harsh operating environments associated with offshore oil and gas production and coastal process facilities.

Polyshrink is applied over the shank of the Nu-Bolt to protect the paint system during installation. Polyshrink is not designed to protect the Nu-Bolt. The material is a cross linked, high-compressive-strength, UV-stable polyolefin, which can remain in service in temperatures up to 230 °F (110 °C).

Coatings – The Nu-Bolt is available in 316 SS or carbon steel with one of two coatings: Hot-dip galvanized or SermaGard. SermaGard is a corrosion-resistant coating reliable in even the harshest offshore conditions.

Half-round I-Rod support – The standard I-Rod material works extremely well for most process piping conditions. In situations with extreme operating temperatures, Deepwater can substitute the more resistant I-Rod HT material. Deepwater has also begun to offer PEEK material for environments that prove too severe for either (though these instances are rather rare). For details about all three materials, see the Nu-Bolt specifications page.

Prevent crevice corrosion at pipe supports

Key Design Points

Half-round Shape

The I-Rod’s half-round shape minimizes contact between the pipe and the support, eliminating the crevice. Keeping water out minimizes corrosion.


The Nu-Bolt assembly provides an electrically isolated stand-off between the pipe and the supporting beam or saddle clamp. This allows for easy maintenance and inspection, while preventing galvanic corrosion between dissimilar metals (the pipe and support).


I-Rod also has excellent compressive strength and a very low friction coefficient. Nu-Bolt assemblies have been in continuous operation since 1989 with no reported failures. See the 13-year study on one of the first platforms to specify I-Rod for all of the structure’s pipe supports.