The Acid Receiver was removed from a chemical production site installation following customer concerns regarding the flange integrity and the receiver was transported to Pump Group for repair.
The tank has a metal shell lined with polypropylene and then wrapped with glass fibre. Upon inspecting the tank, it became clear that both the PN16 Plastic flanges had been heavily corroded and were no longer safe to use in their current state.
It appeared that acid had slowly leaked past the gaskets on both the flanges, and the acid had corroded through the glass fibre, the polypropylene and even the metal shell.
Pump Group engineers proposed a course of action to remove the damaged flanges and rebuild new flanges using Belzona 1111 Super Metal. Belzona 1111 was selected because it is a metal repair composite which has excellent adhesion to metals and plastics, meaning it can be used to both re-form the flanges and bond the flanges to the tank.
The damaged flanges were cut off and the edges prepared by removing the glass fibre and polypropylene 2” back from the existing flanges and then grit blasting the necessary areas.
A mild steel forming plate was manufactured and bushes welded on which had the same PCD and clearance hole size as the existing flanges. 2 split rings were manufactured our of 316 Stainless Steel which were located behind the flange faces.
The flanges were then rebuilt with Belzona 1111 using the forming plate and split rings to ensure the correct size. Belzona 1111 was used to bond the rebuilt flanges to the tank, and the mould and split rings were released once the Belzona had cured.
The OD of the Nozzles and flanges were coated with Belzona 1321 Ceramic Super Metal. Belzona 1321 is designed to provide corrosion resistance to surfaces – it has high chemical resistance which will prevent acid attack causing damage to the flanges should leakage occur in the future.
For more information on how we can utilise our extensive Belzona knowledge and Coating Facilites to assist your company with your operational needs, please contact a member of our Repairs Team on +44 (0)161 864 4678 or via email firstname.lastname@example.org.