How to Insulate Pipe Bends with ArmaFlex: A Step-by-Step Guide

At PipeLagging.com, we’re committed to helping you achieve professional insulation results. Insulating pipe bends can be challenging, but with ArmaFlex’s highly flexible elastomeric insulation, you can create neat, effective fitting covers for elbows and bends. This guide walks you through the process, highlighting best practices to prevent issues like condensation caused by insulation compression.

Why Proper Bend Insulation Matters

When insulating pipe elbows, simply sleeving insulation tubes over the bend can lead to kinking in the throat of the bend, reducing insulation thickness. In cold applications, such as air-conditioning or refrigeration systems, this compression can cause condensation on the insulation surface, compromising performance. To avoid this, fabricating segment bends from ArmaFlex tube material ensures consistent thickness and a reliable seal.

Two Key Techniques for Insulating Bends

1. Sleeving Over

ArmaFlex tubes can be sleeved directly over pipes, including bends, for straightforward applications. Here’s how to do it right:

• Ensure a smooth fit: The pipe surface must be clean and dry so the tube can slide on easily.
• Push, don’t pull: Always push the ArmaFlex tube over the pipe to avoid tearing the material. Pulling can strain and damage the insulation.

This method works well for gentle bends but may not suffice for tighter curves where kinking is risky.

2. Fabricating Segment Bends

Fabricating segment bends is essential for tighter bends or applications where kinking could occur. This method maintains insulation thickness and prevents seam failure in self-adhesive tubes. Follow these steps:

• Use standard ArmaFlex tubes: Avoid self-adhesive tubes for bends, as the adhesive can compress and fail under strain.
• Cut precise segments: Most bends require a segment bend with one middle part. Two or three middle parts may be needed for larger or obtuse bends.
• Follow the ArmaFlex template: Printed on every ArmaFlex box, the template guides you in cutting tubes at the correct angles based on pipe circumference, diameter, and radius.

Pro Tip: Use sharp, high-quality knives for clean cuts. Precise cutting ensures a professional finish and proper fit.

Step-by-Step Fabrication Process

1. Prepare the Template:

   • Lay the ArmaFlex template (found on the box) printed side up on a workbench.
   • Align the ArmaFlex tube parallel to the template’s horizontal baseline.
   • Select the appropriate angle from the template and cut along the indicated line.

2. Cut the Tube:

   • Use a sharp knife to cut the tube segments accurately. The yellow lines on the template indicate where to cut.
   • For detailed angle measurements, refer to the ArmaFlex Application Manual.

3. Apply ArmaFlex Adhesive:

   • Coat both surfaces to be bonded with a thin, even layer of ArmaFlex adhesive.
   • Allow the adhesive to tack dry (test with a fingernail—it should be slightly tacky but not stringy).
   • Press the surfaces together firmly, working from the inside out to ensure a strong bond.

4. Secure the Insulation:

   • Apply adhesive around the entire circumference of the tube ends, using a width at least equal to the insulation thickness, to secure them to the pipe.
   • Avoid glueing seams under tension—always use compression for a durable seal.

Note: Never use the wet-bonding technique for butt joints under compression, as it can weaken the bond.

Benefits of ArmaFlex Prefabricated Fittings

For even faster and more consistent results, consider ArmaFlex prefabricated elbows and T-pieces. These fittings offer:

• Time and cost savings: Reduce installation time and minimise cutting errors.
• Consistent quality: Factory-made fittings ensure higher performance and reliability.
• Less material waste: Avoid losses from incorrect cuts.

Additional Tips for Success

• Use ArmaFlex adhesive and cleaner: These products are designed to work seamlessly with ArmaFlex insulation for optimal results.
• Watch the experts: Armacell’s application videos, available at armacell.de or their YouTube channel, clearly demonstrate the fabrication process.
• Consult the manual: The ArmaFlex Application Manual provides detailed instructions for fabricating bends from tube and sheet material.

Why Choose ArmaFlex?

ArmaFlex’s flexibility makes it the go-to choice for insulating pipes, especially on bends. Its elastomeric tubes can be easily slit and wrapped around existing pipework, with seams glued securely. By fabricating segment bends for elbows, you ensure long-lasting insulation that prevents condensation and maintains energy efficiency.

Ready to insulate your pipe bends like a pro? Visit PipeLagging.com for ArmaFlex products and more expert tips in our Knowledge Hub.

Content adapted from Armacell’s installation guide by Dipl. Ing. Michaela Störkmann, Technical Manager EMEA.