Problem Description  

Flanged joints are subject to settling. This means that the sealing forces decrease over the service life, regardless of the sealing concept. The usual response to settling is to set the sealing force in the installed condition so high that the loss of force over the service life is less than the excess force. 

Sealing systems with frequently changing operating conditions, in particular rapid temperature changes, and sealing systems that are subjected to mechanical loads, such as vibrations or pressure surges, can compensate for settling phenomena or the drop in force in intermediate states only up to a certain point via the excess force. In this case, the minimum sealing force can be maintained by installation of an additional spring loaded system. This spring loaded system responds to settling phenomena by largely compensating for the loss of volume or the drop in force by re-pressing. 

Requirements for a re-equipment

• Support of the equipment designed for the static condition
• Compensation of settling phenomena
• service life > 6 years
• Pre-tested documentation

Solution Approaches

• Calculation of the required inherent elasticity of the entire sealing connection
• Risk assessment for leakage based on the calculation results
• Selection of the required spring material

Design Conditions

• Design pressure: up to approx. 400 bar
• Design temperature: from approx. -200°C to approx. +900°C
• Gasket diameter: up to approx. 6 meters
• Screw size: up to approx. M110