Designed for catenary Risers used to transport high pressure gas or multi-phase fluids where large internal pressure fluctuations are expected. The bellows shields the elastomeric flex element from the gaseous environment and prevents explosive decompression damage to the flex element's rubber surface.

The bellows is a self-equilibrating pressure-balanced system in which the bellows extends or compresses to compensate for changes in the internal pressure and cocking angle. The cavity between the body/flex element and the bellows is sealed and filled with Compenol™ a water-propylene glycol based corrosion inhibiting fluid.

Prevents Explosive Decompression Damage (ED)
Provides Thermal Convection Protection

The patented Metallic Bellows System is an optional feature for SCR FlexJoint^® systems. The principle purpose of the bellows system is to shield the flex element from the gaseous environment responsible for explosive decompression damage of the elastomer layers. Although the elastomers utilized in the SCR FlexJoint^® have proven to be highly resistant to the fluids and chemicals passing through the SCR FlexJoint^®, the bellows provides additional insurance by acting as a barrier to these fluids. The increased demand for High Pressure/High Temperature (HPHT) SCR FlexJoint^® has established a secondary benefit for the bellows as a means to reduce thermal convection that could affect the service life of the elastomeric flex element within the SCR FlexJoint^®.

The bellows is a self-equilibrating pressure-balanced system in which the bellows extends or compresses to compensate for changes in the internal pressure and cocking angle. The cavity between the body/flex element and the bellows is sealed and filled with a corrosion inhibiting fluid which meets service temperature and pressure requirements.

The option to use a bellows system in a FlexJoint^® is determined by evaluating the application requirements and is verified during preliminary engineering design.