Study and design of a system for restoring the pressure tightness of the flanges with a Ring Joint seat of a heat exchanger



VED solution with Graface supplying quality and competence!


F ollowing the reassembly of the heads, after excluding a exchanger tube because it was damaged, during the hydraulic test phases, one of the two heads showed water leakage already at the pressure of 20 bar. Failing to resolve, with usual systems, we were involved in the search for a solution that would allow the system to restart..

On one side of the equipment, the Ring Joint remained attached to the body flange, firmly anchored to it and despite repeated attempts to remove it, it was preferred not to insist too much. On the other side, removing the Ring Joint without difficulty, the sealing surfaces were restored by turning; this has contributed to a reduction of the section and consequently an excessive approach of the flanges, to the assembly. If on the one hand the surface conditions of both heads were quite regular and free from appreciable defects, on the body flange there were excessive corrosion signals for a Ring Joint seat. Based on the information received, the study was carried out to restore the seal conditions.

Work execution

It was decided to use the technical features of the Graface to solve the problem, acting directly in the plant quickly. Then the conical surfaces were developed for the Ring Joint seats, and the shapes were cut. In the Plant, the final phases of the activity involved coating the conical seats of the Ring Joint.

The assembly of the Ring Joint and the tightening of the head, carried out by another company, was supervised by VED personnel.

After the equipment was assembled, the hydraulic test was performed and no leak was detected.


In Brief

The use of Graface has promptly resolved a problem directly in the plant, combining experience with product quality. Therefore the seal is not obtained only thanks to an element, which is made up a flange joint (example: the gasket), but the set of its components.