gas spring

A tension gas spring (also called a pull-type gas spring) works on the opposite principle of a standard compression gas spring. Instead of pushing outward, it pulls inward.

1. Basic Structure

A tension gas spring consists of:

• Cylinder filled with high-pressure nitrogen gas

• Piston rod connected to a piston inside the cylinder

• Seal and guide to prevent gas leakage

• End fittings for mounting

In its natural (unloaded) state, the rod is fully pulled into the cylinder.

2. Working Principle

● Resting State

• The nitrogen gas inside the cylinder is pre-pressurized.

• Gas pressure acts on the piston area.

• This pressure creates a constant pulling force, keeping the rod retracted.

● Extension (Pulling the Rod Out)

• An external force pulls the rod outward.

• The internal gas volume increases.

• Gas pressure slightly decreases but still resists extension.

• When released, the gas pressure pulls the rod back in automatically.

● Retraction

• Once the external force is removed:

  • The stored gas energy pulls the piston rod inward.

  • The force remains nearly constant throughout the stroke.

3. Force Characteristics

• Force direction: inward (tension force)

• Force curve: relatively flat, with slight increase near full retraction

• No external power required

• Can include damping near the end of stroke if designed

4. Comparison with Compression Gas Spring

5. Typical Applications

Tension gas springs are used when a controlled pulling force is needed:

• Toolboxes & equipment covers

• Industrial machine guards

• Cable balancing systems

• Access panels & inspection doors

• Furniture (hidden pull mechanisms)

These are common in industrial equipment similar to applications you may already be familiar with in gas spring systems.

6. Key Advantages

• Compact installation

• Clean, maintenance-free

• Smooth and controlled motion

• Long service life