SiC Rings for DGS System

Semicorex SiC Rings for DGS Systems are core sealing components for high-speed rotating equipment such as centrifugal compressors. By machining precision hydrodynamic grooves (such as spiral grooves) on the ring surface, they generate a hydrodynamic damping effect during rotation, forming a stable gas film of only 3-5 micrometers, achieving "non-contact" operation under dynamic conditions. This product uses high-performance atmospheric pressure sintered silicon carbide (SSiC) material, possessing extremely high hardness (2800 kg/mm²), excellent thermal conductivity (120 W/m.K), and outstanding corrosion resistance. It maintains extremely high dimensional stability and flatness (<0.6μm) even under extreme environments such as high pressure, ultra-high speed, and acidic gases. With this advanced design resulting in near-zero friction, this series of silicon carbide rings is widely used in oil and gas transportation, petrochemicals, and hydrogen compression, significantly reducing system power consumption while ensuring long-term, low-maintenance, and safe operation of critical units.

By leveraging advanced material science and precision engineering, these rings ensure zero-contact operation, significantly reducing downtime and maintenance costs in mission-critical industrial applications.

1. The Principle of Dry Gas Seals (DGS)

A Dry Gas Seal is a non-contacting, end-face mechanical seal that uses a thin film of gas—typically the process gas itself or an inert buffer gas like nitrogen—to separate the seal faces.

The core mechanism relies on hydrodynamic lift. One of the seal faces (usually the SiC rotating ring) is etched with high-precision micro-grooves (often spiral, "T," or "U" shaped). As the shaft rotates at high speeds, these grooves draw gas inward, increasing the pressure between the stationary and rotating faces. This creates a stable, microscopic gap (typically 3 to 5 microns).

Because the faces never physically touch during normal operation, friction is nearly eliminated, and wear is drastically reduced compared to traditional oil-lubricated seals. However, this "non-contact" state requires the seal rings to be perfectly flat and capable of withstanding the immense centrifugal forces and thermal gradients generated during startup, shutdown, and transient conditions.

2. Silicon Carbide (SiC) Parameters and Material Advantages

We utilize Pressureless Sintered Silicon Carbide (SSiC) and Reaction Bonded Silicon Carbide (RBSiC) to manufacture our DGS rings. SSiC is generally preferred for DGS due to its superior chemical resistance and higher hardness.

Technical Specifications & Material Properties

Our SiC Rings for DGS System are manufactured to meet the most stringent industry standards:

Key Advantages

Thermal Stability: SiC maintains its mechanical strength at temperatures exceeding 1000°C, ensuring the ring does not warp under the heat generated by high-speed gas shearing.

Chemical Inertness: With a pH range of 0–14, our SiC rings are immune to the corrosive effects of "sour gas" (H2S), CO2, and other aggressive process chemicals found in petrochemical refining.

High Elastic Modulus: The stiffness of SiC prevents "coning" or deformation of the seal face under high-pressure differentials (often exceeding 100 bar).

Superior Surface Finish: We achieve a mirror-like finish (Ra < 0.05 μm), which is critical for the precision etching of hydrodynamic grooves.

3. Industrial Applications

Our SiC Rings for DGS System are the "heart" of sealing solutions across various high-stakes sectors:

Oil & Gas (Upstream/Midstream): Used in high-pressure centrifugal compressors for natural gas pipeline transmission and offshore gas reinjection.

Petrochemical Processing: Essential for ethylene, ammonia, and methanol production where gas purity and leakage prevention are safety-critical.

Power Generation: Employed in steam and gas turbines to manage buffer gases and prevent hazardous emissions.

Emerging Energy: Increasingly utilized in Hydrogen (H2) compression, where the small molecular size of hydrogen demands the highest possible precision in seal face flatness.