Knock-off Valve

Our dump truck hydraulic limit valve is the critical safety component that prevents over-lifting. Engineered with high-strength alloy, it ensures precise control with a 24-26mm total stroke and a wide 10-22mm adjustable range, allowing you to perfectly set the maximum dump body angle for different loads and sites.

Activated by responsive air control (0.6-1.2 MPa), this valve is a key part of your truck's safety system, effectively preventing equipment damage and rollover risks from over-extension. Compared to basic knock off valves, our adjustable knock off valve offers superior precision, enhanced operational safety, and easy installation across various models. This translates to protected equipment, minimized downtime, and greater peace of mind during demanding hauling operations. Contact us to find your precise safety solution.

Dump truck knock-off valve (hydraulic limit valve) is a critical safety component designed to stop the dump body from over-lifting. By limiting the maximum tipping angle, it helps protect cylinders, frames, and hydraulic systems—while reducing rollover risk during heavy hauling. FLYBY offers a reliable, adjustable knock off valve range engineered for demanding job sites and consistent daily operation.

Built for safety-critical performance

Unlike basic limit valves with fixed settings, FLYBY’s adjustable knock-off valve is designed for precise angle control across different payloads and work environments. It features a 24–26 mm total stroke and a wide 10–22 mm adjustable range, allowing operators or maintenance teams to set the maximum dump body angle with accuracy. This is especially useful for sites where load type, tipping surface, or operating conditions vary frequently.

Responsive pneumatic activation

This series is activated by air control at 0.6–1.2 MPa, enabling fast, consistent response as the dump body reaches the preset limit. The result is predictable stopping behavior that helps prevent over-extension, reduces stress on key components, and supports safer tipping cycles.

Durable construction for tough conditions

FLYBY knock-off valves are engineered with high-strength alloy for durability in harsh field conditions such as mining, construction, and intensive transport routes. The design focuses on stable control, dependable sealing, and long service life—helping reduce unplanned downtime and repair costs.

Easy installation and model coverage

Designed for practical maintenance and retrofits, FLYBY knock-off valves support easy installation across various dump truck models. The product list includes multiple options to match common configurations, such as:

• Dump Truck Hydraulic Lock YYS-08L4

• Dump Truck Limit Valve XYF-E20L-02

• Dump Truck Hydraulic Knock-off Valve XQF-22 / XQF-22W

• XQF-25 Limiting Valve for Tipper Truck

• Pneumatic Hydraulic Knock-off Valve XQF-23

  
  

Customization, support, and dependable supply

Need a specific setting range, interface, or installation fitment? FLYBY supports customized solutions to match your truck system and safety requirements. With stable manufacturing and quality control, we help customers secure durable products, fast delivery, and global supply support for ongoing maintenance and fleet operations.

FAQ

Q1: What does a dump truck knock-off valve do?
A knock-off valve (hydraulic limit valve) prevents over-lifting by stopping the dump body at a preset maximum angle, reducing equipment damage and rollover risk.

Q2: What’s the difference between a knock-off valve and a basic limit valve?
An adjustable knock off valve allows fine-tuning of the maximum dump angle (e.g., 10–22 mm adjustment range), offering better precision for different loads and site conditions.

Q3: What air pressure is required for a pneumatic knock-off valve?
This series is designed for 0.6–1.2 MPa air control to trigger responsive, consistent operation.

Q4: How do I choose the correct hydraulic limit valve model (XQF-22, XQF-23, XQF-25)?
Selection depends on your truck model, installation interface, required adjustment range, and pneumatic/hydraulic circuit layout. Share these details to confirm compatibility.

Q5: Can the knock-off valve be customized?
Yes. FLYBY supports customization for fitment and operating requirements to help achieve reliable safety control and easier installation.

Applications / Selection Guide Table