A European fertilizer plant had a leak on a set of 12" lap joint flanges. Service was 72% ammonia and 28% carbamate, with pressures to 225 psi and temperatures to 140°C (284°F).

Due to the high corrosive level of the service, the material of construction on the line was stainless steel, while the material of the lap joint flanges was carbon steel.

Because of this plant engineers did not want standard carbon steel flange clamps over the leaks. Their reasoning was the corrosive service might come in contact with the flanges.

A partial isolation was fabricated and installed directly over the leaking area. The repair sealed the leak.

Approximately one week later, the leak traveled to a new location.

Team engineers then designed a special clamp with smooth tongue and very shallow crunch teeth on the I.D. The clamp was designed and fabricated in sections to facilitate installation without having to remove all the studs at once. The design also prevented flange exposure to the service.

Each segment was installed until all were securely attached to one another.

The clamp then was pumped with Team sealants and the leak sealed completely.

Plant officials experienced no further leakage problems with the flanges.