Nu-Bolt® – most popular method of using I-Rod®
Nu-Bolts® utilize U-bolts to secure pipes to supports while they’re resting on corrosion-preventing I-Rod®. They’re available in combinations of materials that perform even in the harshest, high-temperature environments. There are also gripping configurations for firmly securing the pipe and non-gripping options that allow thermal expansion without lateral movement. Custom sizes to match any needs are available in addition to our catalog offerings.
What is a Nu-Bolt®?
1. Coated fasteners: Carbon-steel U-bolts and nuts are available coated with hot-dipped galvanized or SermaGard™. ArmorGalv® is also available, as are 316 SS U-bolts.
2. I-Rod® material is a durable, half-round thermoplastic with high compressive strength and little-to-no creep over time. I-Rod® and I-Rod® UV+ (white) can be used up to 181°F (83ºC), I-Rod® HT (amber) up to 340°F (171ºC) and I-Rod® PEEK (tan) up to 480°F (249ºC).
3. Choose gripping or non-gripping U-bolts: Gripping Nu-Bolts® do not allow pipe movement; Non-gripping Nu-Bolts® allow movement due to thermal expansion and contraction. XL Nu-Bolts® are non-gripping with slightly larger dimensions to prevent coating damage during pipe movement.
4. Polyshrink™ is a UV-stable, cross-linked polyolefin applied over the shank of the U-bolt to protect the pipe’s coating during installation. Standard Polyshrink™ temps: Up to 110ºC (230ºF); Hi-Temp: Up to 220ºC (428ºF).
Full MTRs are provided with every order to verify quality and origin.
Video: How I-Rod® works
Nu-Bolt® options
Polyshrink™
Two options for Polyshrink™ are available: Standard – up to 230°F / 110°C, and high-temp HT – up to 428°F / 220°C. U-bolts can also be ordered without Polyshrink™.
U-bolt and fastener coatings
A36 domestic steel U-bolts can be ordered with the following coating options: Hot-dip galvanized and SermaGard®. U-bolts and nuts are also available in 316SS.
Four I-Rod® material choices
Nu-Bolt® is rated to perform in temperatures ranging from -166º F to 480º F (–110ºC to 249ºC) . I-Rod® and I-Rod® UV+ (white) can be used up to 181°F (83ºC), I-Rod® HT (amber) up to 340°F (171ºC) and I-Rod® PEEK (tan) up to 480°F (249ºC).
Gripping or non-gripping
Nu-Bolts® are available with a non-gripping configuration, where the I-Rod® is secured by nuts above and below rather than just below. This allows thermal expansion without lateral movement. Nu-Bolt® XL offers slightly larger clearances to further prevent binding that could damage pipe coatings during movement.
Key design points
Half-round shape: I-Rod's half-round shape minimizes contact between the pipe and the support, eliminating the crevice that traps water. Keeping water out minimizes corrosion.
Easier maintenance: A Nu-Bolt® assembly provides an electrically isolated stand-off between the pipe and the supporting beam or saddle clamp, which allows for easy maintenance and inspection. This also prevents galvanic corrosion between dissimilar metals of the pipe and support.
Durability: I-Rod® has excellent compressive strength and a very low coefficient of friction. Nu-Bolt® assemblies have been in continuous operation since 1989 without a single reported pipe failure.
Withstands extreme temperatures: With four materials to choose from, Nu-Bolt® is rated to perform in temperatures ranging from -110º F to 480º F.
How to order Nu-Bolt®
Standard and custom sizes available
Nu-Bolt® is only available from Deepwater Corrosion Services and our licensed distributors and international resellers. Nu-Bolts® are sized to fit API standard pipe sizes. To order, we need to know:
1. Pipe size
2. Temperature requirements
3. Coating
4. Nuts and washers
5. Gripping or non-gripping
Download Nu-Bolt® 3-D CAD models
Download free CAD models of Nu-Bolt® assemblies for use in designing your next project. Hundreds of files in the most popular CAD formats are available.
Metric Nu-Bolt® download
Nu-Bolts are also available in metric sizes.
This downloadable list shows part numbers for metric Nu-Bolt® variant hot dip galvanized U-bolt with Polyshrink, 4 heavy hex nuts and a cut-and-drilled piece of white I-Rod® (max temp. +83c).
Nu-Bolt® specifications
Nu-Bolt® assembly specifications
Complete specifications for I-Rod® material, U-bolts and the Polyolefin heat shrink used in Nu-Bolt® assemblies are available on our specifications page.
I-Rod® material is a special type of plastic
I-Rod® material is the key to the Nu-Bolt's success. I-Rod® material has a high compressive strength and is subject to very little creep over time, so it can last 20 years or longer in the field.
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