Preventing Catastrophic Failure: HU25044-22G Induced draft fan connecting rod bias

Description

In power plant operations, the sudden fracture of the Induced Draft (ID) Fan Adjustable Vane Link Rod frequently leads to major forced outages and significant financial loss. Crucially, a fracture is often preceded by a clear warning sign—the key is monitoring the deviation between "Hydraulic Cylinder Stroke" and "Adjustable Vane Angle."
In AP-type ID Fans with adjustable pitch vanes, the hydraulic cylinder drives the synchronized rotation of the vanes via a link rod system. Under normal conditions, the stroke signal fed back by the servo valve (e.g., HU25042-221G) and the angle feedback from the rotary encoder should maintain a highly linear relationship.
If the link rod experiences looseness, wear, or micro-cracks, this rigid mechanical connection is compromised. The symptom is clear: The hydraulic stroke changes normally, but the vane angle response is delayed, jerky, or fails to move entirely.
A common anomaly seen on the DCS is "Command Change, Current Spikes, but Vane Angle Remains Unchanged." This is the classic precursor signal before a catastrophic link rod failure.

 Implementing Deviation Alarm Logic in DCS
To leverage this predictive maintenance opportunity, we recommend implementing the following deviation alarm logic in the Distributed Control System (DCS):
•    Normal Deviation:  ≤ ±2%
•    WarningPre-Alarm: Deviation continuously exceeds >5% for more than 10 seconds to Trigger Pre-Warning.
•    Trip Immediate Shutdown: Deviation exceeds >8% OR the angle shows zero response to Immediate Shutdown and Inspection.

This method has been successfully implemented in multiple 600MW supercritical units, allowing for the detection of link rod anomalies hours or even days before failure.
 Hardware Solution: Upgraded Link Rod for High Reliability
Even the most sensitive monitoring requires reliable hardware support. Traditional link rods often suffer from fatigue failure due to inadequate materials and manufacturing processes in high-temperature and high-vibration environments.
We offer the optimized Hydraulic Cylinder Group Link Rod (HU25044-22G), which features:
•    Material: High-strength alloy steel, integrally forged.
•    Strength: Tensile strength ≥ 900MPa.
•    Fatigue Life: Fatigue life is improved by 3 times compared to conventional parts.
•    Structural Optimization: Engineered stress structure completely eliminates the risk of root cracking.
This upgraded link rod has achieved a track record of zero breakages over 20,000+ operating hours.

We supply the following fan accessories.

HKZX-2025-11-07