What is a Dry Gas Seal?
A dry gas seal is a non-contacting seal that operates without lubrication. The dry gas seal uses a thin gas film to separate rotating and stationary parts. Spiral grooves on the dry gas seal faces create a lifting force. This force maintains a tiny gap, preventing contact during operation.
Advantages of Dry Gas Seal
The dry gas seal offers a non-contacting design, reducing wear. The dry gas seal works efficiently in high-speed centrifugal compressors. It provides lower leakage rates than oil seals. The dry gas seal reduces maintenance costs over time. It is environmentally friendly since it avoids oil leaks. The dry gas seal handles various process gases effectively.
Disadvantages of Dry Gas Seal
The dry gas seal has a higher initial cost than mechanical seals. It requires clean, dry sealing gas for optimal performance. The dry gas seal struggles with liquids or solids in the gas. It reacts sensitively to pressure and temperature changes. The dry gas seal needs advanced support systems for monitoring.
When to Use Dry Gas Seal
Use a dry gas seal in centrifugal compressors for dry gas applications. The dry gas seal excels in natural gas processing and petrochemical industries. Choose a dry gas seal when minimal leakage is critical. The dry gas seal suits high-pressure, high-speed operations. It is ideal when long life and low maintenance matter.
How is a dry gas seal worked?
Dry Gas Seals (DGS) are basically consisting of a rotating ring and a stationary ring. During operation, grooves in the mating ring generate a fluid-dynamic force causing the rotating ring to separate from the stationary ring, creating a “running gap” between the two rings. The running gap varies from 3 to 10 microns depending on the seal type.
Where are dry gas seals used?
Dry gas seals are mechanical seals but use other chemicals and functions so that they do not contaminate a process. These seals are typically used in a harsh working environment such as oil exploration, extraction and refining, petrochemical industries, gas transmission and chemical processing.
What kind of devices would need to use dry gas seals?
Dry gas seals are the preferred sealing solution for centrifugal compressors and other high-speed, dry gas applications. They are particularly well-suited for: Natural gas processing, transmission, and storage.
What causes dry gas seal failure?
Insufficient pressure of the buffer gas during startup can cause the process gas inside the compressor to go through dry seal faces. Exposure to the dirty gases will make the dry gas seal groove ineffective causing the damage to the seal faces.