How to Apply a Belzona Flange Corrosion Protection System

The integrity of flanges is critical to the containment of fluids in a piping system. In our latest video, we demonstrate how to fully encapsulate flanges and bolt fastenings to protect against moisture ingress and prevent corrosion. Find out more:

Insufficient external protection of corrosive areas can lead to rapid and extensive damage to the flanges and fastenings which will accelerate the deterioration of the system’s integrity. The Belzona 3412 encapsulation system can be applied to new or deteriorated equipment to provide outstanding long-term corrosion protection.

Materials Used:

To encapsulate this flange, we used Belzona 3412, Belzona 8411 (Release Agent), Belzona 9431 (Instant Bridging Tape) and Belzona 9311 (Reinforcement Sheet)

How-to Guide:

Step 1: Clean the surface of the pipe and flanged connections to remove all dirt, grease and other surface contaminants.
Step 2: Thoroughly abrade the surface with abrasive paper (sand paper) or wire brush to remove all gloss and provide a good key for the Belzona coating.
Step 3: Apply masking tape over the two bond areas to protect the pipe areas from accidental overspray.
Step 4: To allow assess to bolts and flanges in the event of required maintenance, we recommend the application of Belzona 8411 by brush or spray. This also provides an optimum level of corrosion protection.
Step 5: Once the Belzona 8411 is touch dry, remove the masking tape.
Step 6: Re-apply fresh masking tape.
Step 7: To seal the gap between the flange faces, cut a strip of Belzona 9341 to the correct width and apply over the gap.
Step 8: Fit plastic caps over the nuts/bolts.
Step 9: Empty the entire contents of the Belzona 3412 base and solidifier and thoroughly mix in the bowl provided for at least three minutes.
Step 10: Using a spatula, transfer the mixed Belzona 3412 to the flange face and bolts.
Step 11: Using long, light strokes, brush the material over the entire area ensuring it does not extend outside the prepared area.
Step 12: While the first coat of Belzona 3412 is still wet, bed strips of Belzona 9311 around the circumference of both ends of the pipe and the flange.
Step 13: Mix and apply the second coat of Belzona 3412

Accessing the flanges and bolts during required maintenance:

Step 1: Using a sharp knife, cut through the Belzona membrane in the gap between the flanges.
Step 2: Carefully peel back the material and remove the bolt caps.
Step 3: Once the inspection is complete, fold the Belzona 3412 back to its original position.
Step 4: To re-seal the repair, mix a further quantity of Belzona 3412 and brush apply it onto the cut area around the flange incorporating Belzona 9311.

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