High-Tensile DYL2420-75 Fan Blade Screw: Technical Specs and Low-Temperature Impact Resilience

I. Product Overview

The DYL2420-75 Blade Screw is a specialized fastener designed specifically for AP Series variable-pitch axial fans (such as the HU25040-221 model). Its core function is to ensure a rigid connection between the rotating fan blades and the hub while maintaining concentricity and balanced force distribution during pitch adjustment.

Operating as a critical part of the fan's blade adjustment transmission system, this screw works in coordination with the DYL2420-60 Blade Bolt, TY98010/TY96010 Cylinder Linkages, and other actuator components. The installation precision and performance stability of these screws directly dictate the fan's operational efficiency and overall service life.

II. Technical Features & Advantages

The DYL2420-75 screw offers technical superiority through rigorous material selection, precision process control, and performance parameters that exceed standard requirements. It fully complies with the technical specifications for high-load fasteners outlined in variable-pitch axial fan manuals.

1. High-Standard Material and Process Control

The screw is manufactured from Grade 10.9 high-strength alloy steel and undergoes a strict quenching and tempering (Q&T) heat treatment process.

• Hardness Range: Stabilized at HRC 33-39 (or HV 335-380).

• Structural Integrity: This ensures the rigidity required to withstand centrifugal forces at high rotational speeds while maintaining the toughness needed to handle impact loads from fluctuating operating conditions, effectively eliminating the risk of brittle fracture.

2. Superior Mechanical Performance Parameters

The measured mechanical properties of the DYL2420-75 consistently exceed the nominal requirements for Grade 10.9 fasteners, ensuring a high safety margin for fans operating at rated speeds (e.g., 990 rpm).

The excellent low-temperature impact toughness makes this screw ideal for power plants located in high-altitude or frigid regions, meeting the most demanding environmental technical specifications.

3. Precision Compatibility and Interchangeability

Designed for seamless integration, the DYL2420-75 offers perfect interchangeability with the DYL2420-60 Blade Bolt and HU26652-22-YJMF Sealing Gasket. This compatibility allows for rapid replacement during maintenance intervals, significantly shortening downtime and reducing economic losses for the power plant.

III. Application Scenarios

The DYL2420-75 is primarily utilized in AP Series variable-pitch axial fans serving as Induced Draft (ID) and Forced Draft (FD) fans in thermal and combined heat and power (CHP) plants.

1. Routine Maintenance and Overhauls

Fasteners must be inspected periodically for wear, corrosion, or fatigue cracks. Timely replacement is vital to prevent catastrophic failure.

• Example: In the maintenance of HU25040-221 fans at the Gansu Electric Power Investment Wuwei CHP Plant, the DYL2420-75 is a standard replacement part to ensure long-term stability.

2. Emergency Repairs and Upgrades

The screw serves as a reliable OEM-grade replacement in upgrading projects or repairs in harsh environments (e.g., mountain wind farms or high-altitude plants). Its high-strength and anti-fracture properties reduce the frequency of equipment failure.

3. "One-Stop" Spare Parts Support

As a professional supplier, we provide the full suite of related components to ensure a complete maintenance solution:

HKZX-2026-01-26