CobaDGS -
Zero Emission Solution

CobaDGS -
Zero Emission Solution

CobaDGS - </br>Zero Emission Solution
CobaDGS drawing
CobaDGS drawing
Item Description
1 (Seat) Rotating seal face
2 (Seal face) Stationary seal face
3 Thrust ring
4 Spring
5 Shaft sleeve
6 Housing
7 Labyrinth
8 DGS as seal on atmoshere side
9 CobaSeal as separation seal

A* Buffer gas supply - optional
B  Primary vent
C  Seal gas supply
D  Separation gas supply
S  Secondary vent

CobaDGS -
Zero Emission Solution


The sealing solution for reduction of methane-/ process gas emissions
  • Gas-lubricated
  • Bi-directional
  • Ready-to-fit cartridge unit
  • Available for following seal arrangements: single and tandem
  • Co-axial primary seal
  • Separation seals as CobaSeal, carbon rings or labyrinths optional


  • No methane-/ process gas emissions
  • Supplied with clean nitrogen (no dew point and dirt problems)
  • Robust
  • Offers higher safety than a double seal
  • Upgrade-possibility of existing single, double and tandem seals
  • No modification of the compressor necessary
  • Efficient alternative to hermetically sealed systems
  • For compressors with gas- and steam turbines, as well as with electric drive

Operating range

Shaft diameter:
d = 25 … 350 mm (0.99“… 13.78“)
p = from vacuum up to 160 bar (2,321 PSI)
Design temperature:
t = -46 °C … +230 °C
(-51 °F ... +446 °F)
Sliding velocitiy:
vg = up to 140 m/s (459 ft/s)

Project specific special designs possible


Stationary seal face: Silicon carbide with DLC-coating, DiamondFace-coating optional
Rotating seal face (Seat): Silicon carbide with DLC-coating, DiamondFace-coating optional
Secondary seals: FKM or other elastomers, depending on product gas composition
Metal parts: 1.4006 or other stainless steels

Other materials on request.
Dimensions on request

Standards and approvals

  • NACE


Notes/Info Methane Emissions*
Methane is the second largest contributor to climate change after CO2. Methane is emitted in smaller quantities than CO2, but it’s warming potential is 80 times higher. Behind agriculture, the energy industry is the largest emitter of methane emissions.

A convincing argument for action
According to the International Energy Agency around 40-50% of current methane emissions from the oil & gas industry could be avoided at negative or at no net cost. This means that many projects to avoid methane emissions even have a positive business case and pay back in a relatively short time because the gas can be sold instead. If all these possible projects would be realized the impact on climate change would be immensely positive.

CobaDGS eliminates
The CobaDGS is the first dry gas seal, which provides the possibility to seal compressors with zero methane emissions even if they have high working pressures. It is a viable and sustainable option for upgrading existing compressors or can be installed in new compressors.

International Energy Agency