K-CBS Circumferential Barrier Seals

Why do users and OEMs prefer Kaydon Circumferential Barrier Seals?

Improved reliability, longer-life dry gas seal performance, greater compressor up-time year after year after year!

Why specify K-CBS in place of a labyrinth or other barrier seal design?

Prevents emissions to the atmosphere.
The K-CBS provides backup protection in the event of dry gas seal failure to prevent flammable and toxic gases from escaping to the atmosphere.

Prevents gas seal contamination from bearing oil crossover.
The most common cause of dry gas seal contamination is bearing oil. This can be caused by inadequate bearing / seal housing separation, poor bearing drain design or piping configuration, or pre-lube, start-up, or transient operating conditions. Bearing oil adjacent to the seal cavity will not be stopped by a labyrinth design. A properly designed barrier seal will prevent oil crossover to the dry gas seal cavity even with flooded bearing cavity conditions.

Reduces buffer gas consumption and cost.
When costly buffer gasses, such as nitrogen, are used, a barrier seal will pay for itself within months and continue to save money over the life off the installation.

Prevents gas seal contamination from process gas.
The second most common cause of dry gas seal contamination is from the process gas itself. Here again, labyrinth designs are not effective in preventing entrained liquids and solids in the process gas from contaminating your dry gas seals. Using the same concept as the K-CBS, Kaydon's Process Circumferential Seal, the K-PCS, will replace the labyrinth with a positive, effective seal. Protect both sides of your dry gas seal with Kaydon circumferential seal technology.

The K-CBS consists of segmented carbon rings with a sealing dam in the bore of the carbon rings. Light contact is generated between the sealing dam and a hardened, rotating shaft sleeve by an extension spring around the circumference of the carbon segments. At initial installation, there is a small gap in the joints of the carbon segments. Over a period of years, there will be some wear of the bore sealing dam. As this wear occurs, the gap closes between the carbon segments. The seal self-adjusts to maintain its designed performance, until the segments finally butt. At this point, the ring is arch bound and continues to function as a clearance seal, providing the same reliable performance.

Specify Kaydon K-CBS barrier seals to your OEM for the following features:

• Dry Gas Seal back-up protection
• Prevent bearing oil contamination of dry gas seal, improving the reliability and time between overhauls for your compressor application
• Lowest buffer gas consumption, quickest return on investment
• Field rebuildable with Kaydon supplied carbon kits, or return to Kaydon for Certified Seal Repair
• K-CBS seal assemblies available as stand-alone seal cartridge, or integrated into a Kaydon K-DGS seal package.
• Contact Kaydon Ring and Seal directly for seal upgrades and retrofits for your existing compressor installations.

K-CBS Circumferential Barrier Seals & Primary Seal Applications

The K-CBS is also applied as the main shaft seal for low pressure applications. The seal is particularly appropriate as a replacement upgrade to labyrinth eductor seal designs, where lowering fugitive emissions or reducing the cost of buffer gas supply are concerns.

Contact the K-CBS applications engineering group at KCBS@Kaydon.com or click here to forward your application details or questions.