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Belzona® Seals Transformer Main Flange



Power (POWR)



Valves, Pipes and Fittings (VPF)


Customer Location:

Power Distribution Company, South Wales


Application Date:

May 2014


Application Situation:

Transformer within electricity substation



The main flange was discharging high volumes of oil through the failing gasket system. In addition, the top and bottom bolt heads were also leaking. Continual tightening of the bolts over the years was no longer proving effective on the aged transformer. The Client sought a comprehensive, long term solution to seal the main flange and bolt heads.



Belzona 1221 (Super E-Metal)

Belzona 1161 (Super UW-Metal)

Belzona 5831 (ST-Barrier)



Mild Steel


Application Method:

Application was carried out in accordance with Belzona Know-How System Leaflet VPF-11. Due to a strict outage period and to enhance full success, the Client dropped the oil level beneath the flange level and created the correct working habitat and heat source to reduce product cure time. The flange joint was sealed by applying Belzona 1161 & Belzona 9341 (Reinforcement Tape). The bolt heads were fully encapsulated using a disposable former containing Belzona 1161. Once cured the former removed and the prescribed areas coated with Belzona 5831.


Belzona Facts:

The leak sealing application was successful and the transformer was duly placed back in service. The flange and bolt heads have shown no further signs of leaking. This has resulted in significant cost saving and eliminated any future risk to the local environment.


Photographs Description

  1. Transformer location
  2. Preparation & cap fitting
  3. Cap removal
  4. Coating with Belzona 5831 to complete the application
Case study pic one


 Case study pic two


 Case study pic three


 Case study pic four


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