Hot Bolting & Leak Sealing on Flange of Live Hydrogen Vessel

Overview

IC Integrity were engaged to mitigate a hydrogen leak on processing plant.

The client had discovered that a 500NB stub section with a blind flange had begun leaking and required an immediate fix to prevent a major shutdown.

Scope

The project had the following specifications:

Structure	500NB blind flange stub on a vessel
Quantity	1
Design Pressure	4000 kPa
Fluid Service	Hydrogen
Design Temperature	700oC
Application Temperature	700oC
Line Status	Operating

Solution

• Hot bolt and re-tension the stud bolts to reduce the leak as far as possible
• Design, fabricate and install a tongue clamp to seal between the existing flange joint
• Inject the entire void with epoxy around the existing gasket and stud bolts to provide a positive seal
• Control the leaking hydrogen through steam suppression

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Benefits

• There was no requirement for hot work at any stage during the installation
• The hot bolting exercise and the clamp installation took only 3 days to complete, minimizing the time spent reinstating integrity whilst the leak was still present
• The operation was able to be completed with the plant online
• Fabrication and design was performed locally ensuring rapid turn around times
• Project completed safely and on time