CobaDGS – The next stage of evolution for centrifugal compressor seals
One plus one makes three.
The new CobaDGS dry gas seal combines the best of two worlds and boosts the performance of high-pressure compressor seals to an outstanding new level.
Until now, manufacturers and operators of turbo compressors have had to accept compromises when it came to choose the right mechanical seal:
Conventional double seals run emission-free when supplied with nitrogen but are only suitable for low pressure applications. They threaten to fail quickly if the N2 supply interrupts. Tandem seals can withstand very high pressures but emit large amounts of harmful process gas like methane or CO2 when vented or flared.
The CobaDGS is the first gas seal for centrifugal compressors
- that reliably prevents climate-damaging emissions,
- copes easily with high operating pressures
- and shows impressive performance without damage even when N2 supply is interrupted.
The CobaDGS is recommended as a sustainable sealing solution for retrofitting in all conventional centrifugal compressors and as excellent first fit solution for original equipment manufacturers. A modification of the compressor housing is usually not necessary.
The CobaDGS strengths and highlights
The CobaDGS prevents any process gas emissions that are technically caused by primary seal leakage during compressor operation. As the seal is pressurized with nitrogen instead of process gas, there is no need for the usual seal venting or flaring of fugitive emissions.
This makes CobaDGS a climate-friendly sealing solution for high-pressure turbo-compressors. Its use contributes significantly to climate protection and is also an efficient alternative to hermetically sealed systems.
Here is a sample calculation to show you how many emissions can be avoided by using the CobaDGS seal in a natural gas pipeline compressor.
In the event of a failure of the nitrogen supply, the CobaDGS shows excellent emergency running characteristics even over days. A quick emergency stop of the compressor is not necessary.
Depending on the operating pressure, only up to 25% of the supply gas escapes in the direction of the process. The product quality remains high.
The CobaDGS can be used as an upgrade for existing single, tandem or double seals. The extremely compact design allows an additional backup seal if required, which further increases the reliability of the seal.
The CobaDGS is as safe in use as a tandem seal and can be operated reliably and emission-free up to 160 bar.
The supply of dry, clean sealing gas eliminates the need to discharge process gas into the atmosphere, which is common with tandem seals. There is no loss of process gas, resulting in significantly lower total cost of ownership.
On request, we provide the CobaDGS together with an optimally designed high-pressure nitrogen generator. The complete system for nitrogen generation and supply comes in a container.
This eliminates the need for costly nitrogen transport, especially for sites in remote, hard-to-reach areas.
The CobaDGS fits almost in any compressor – even in one with smaller seal cavities
Whether in centrifugal compressors with gas turbine, steam turbine or electric drive – the CobaDGS fits in without any problems.
Due to its very compact size, this innovative seal can also be used in compressors with smaller seal cavities, for example to improve rotor dynamics.
Application examples and the advantages
Double seal
with N2 supply
Single CobaDGS
The single CobaDGS acts like a conventional double seal but provides greater safety.
CobaDGS added value
The seal can withstand a temporary failure of the N2 supply without damage thanks to excellent emergency running properties with process gas – no emergency stop required
- Easy-to-Upgrade solution – existing connections and N2 supply can be used
- Significantly smaller – fits into existing cavity
Typical applications
- All applications where double seals are used such as wet-gas compressors
Tandem CobaDGS
The tandem CobaDGS acts like a conventional double seal but provides much greater safety.
CobaDGS added value
- Significantly safer due to additional backup seal without exceeding typical seal cavity
- The seal can withstand a temporary failure of the N2 supply without damage thanks to excellent emergency running properties with process gas – no emergency stop required
- Easy-to-Upgrade solution – Modification of connections usually not necessary; existing N2 supply can be used
Typical applications
- All applications where double seals are used such as wet-gas compressors
Tandem seal
without N2 supply
Tandem CobaDGS
The tandem CobaDGS offers the same safety as a conventional tandem seal but is much more robust and operates completely emission-free.
CobaDGS added value
- Zero Emission – no process gas emissions (e.g. methane)
- N2 keeps the seal clean and makes it extremely robust
- No problems due to contaminated process gas
- Easy-to-Upgrade solution – modification of connections usually not necessary
- Booster not required
Typical applications
- Pipeline compressors
- Makes conventional compressors a cost-saving option to hermetically sealed compressors
- Alternative to leakage recovery system
Tandem CobaDGS
Our recommendation. The seperation seal CobaSeal is currently the best solution for oil sealing on the market with lower N2 consumption than any other system.
CobaDGS-CobaSeal added value
- Highly safe due to excellent emergency running properties
- Zero process gas leakage into the bearing in the event of damage
- Best protection of CobaDGS against contamination with bearing oil
- Highly efficient – significantly reduced N2 or air demand
The CobaSeal shows its full strength also in combination with all other variants. This is only one possibility.
Tandem seal with N2 supply
Tandem CobaDGS
The tandem CobaDGS offers the same safety as a conventional tandem seal but is much more robust and operates completely emission-free.
CobaDGS added value
- Zero Emission – no process gas emissions (e.g. methane)
- N2 keeps the seal clean and makes it extremely robust
- No problems due to contaminated process gas
- Easy-to-Upgrade solution – modification of connections usually not necessary
- Booster not required
Typical applications
- Pipeline compressors
- Makes conventional compressors a cost-saving option to hermetically sealed compressors
- Alternative to leakage recovery system
Wet seal
Tandem CobaDGS
Our recommendation. The seperation seal CobaSeal is currently the best solution for oil sealing on the market with lower N2 consumption than any other system.
CobaDGS-CobaSeal added value
- Highly safe due to excellent emergency running properties
- Zero process gas leakage into the bearing in the event of damage
- Best protection of CobaDGS against contamination with bearing oil
- Highly efficient – significantly reduced N2 or air demand
The CobaSeal shows its full strength also in combination with all other variants. This is only one possibility.
No two applications are the same. We would be happy to go into detail with you and discuss the possibilities for using the CobaDGS in your specific application.
You can find more details on the technical data such as application area, materials, standards and approvals here.
Would you like personal advice, do you have any questions or would you like to order directly? We look forward to supporting you.
