How does a hydraulic torque wrench work?

A hydraulic torque wrench is an advanced industrial tool used for the precise tightening and loosening of bolted joints in applications requiring controlled torque. Its design and operating principle are based on the use of hydraulic power to generate significant forces, enabling it to handle high torque values.

Basic design and components

A hydraulic torque wrench consists of several key components:

• Double-acting hydraulic cylinder
• Ratchet mechanism with a gear
• Removable shaft with square drive
• Adjustable reaction arm
• High-pressure hydraulic system

The design of these wrenches is characterized by its sturdiness and simplicity—the latest models have only three moving parts, which significantly reduces the need for maintenance and increases reliability.

How it works

A hydraulic torque wrench works by using high hydraulic pressure (up to 700 bar) to drive a piston, which generates a force that is converted into torque. The process works as follows:

1. Hydraulic pressure from the pump (electric, pneumatic, or manual) is supplied to the hydraulic piston
2. The hydraulic piston is connected to a ratchet mechanism that converts the piston's linear motion into rotational motion
3. The ratchet mechanism engages with the gear in forward mode, causing the socket to rotate and tightening or loosening the screw
4. After the piston completes its stroke, it retracts, and the detent releases to re-engage at the next position
5. The cycle repeats until the required torque is reached

The innovative design provides a working range of 30–35°, which increases productivity and prevents "tool jamming," a common issue with other torque wrench designs.

Torque control systems

Unlike mechanical wrenches, hydraulic torque wrenches use hydraulic pressure as an indicator of torque. The relationship between pressure and torque is linear and predictable, allowing for precise control of the tightening force.

Torque is adjusted by setting the appropriate pressure in the hydraulic system. Modern hydraulic pumps used with torque wrenches are equipped with precise pressure control systems that allow for accurate setting of the required torque.

Industrial applications

Hydraulic torque wrenches are used in many industries where high-torque bolt connections must be tightened with precision:

• Petrochemical industry
• Energy
• Industrial construction
• Shipbuilding industry
• Railway infrastructure

When choosing a torque wrench, follow this practical rule of thumb: the loosening torque is approximately 250% of the tightening torque, which is important when selecting the right tool.

Advantages of hydraulic torque wrenches

Hydraulic torque wrenches offer a number of significant advantages over other tightening methods:

• The ability to generate very high torque despite the tool's relatively compact size
• High-precision torque control
• Ability to work in hard-to-reach areas thanks to optional joints (e.g., the TSP300 joint, which provides 360° rotation on the X-axis and 160° rotation on the Y-axis)
• A two-way mechanism that allows for both tightening and loosening
• Improved workplace safety by eliminating the need for heavy manual labor

The modern design of hydraulic wrenches fully encloses all moving parts, minimizing pinch points and enhancing operator safety.

Summary

A hydraulic torque wrench is an advanced technical solution for the controlled tightening of bolted joints. By utilizing the principles of hydraulic power, these tools enable the precise application of high torque while maintaining a compact design and high ergonomic performance. Their design, based on a hydraulic piston and a ratchet mechanism, ensures reliability and repeatability of operations, which is crucial in industrial applications requiring strict control of bolted joint parameters.