Changzhou LongXiang Gas Spring Co.,Ltd

A gas spring, also called a gas strut, uses compressed nitrogen and a precisely controlled piston system to provide lifting, holding, damping or counterbalancing force. Correct selection is not based on overall length alone. Force, stroke, mounting geometry, temperature, cycle frequency and end fittings must be considered together.

1. Define the required function

First decide whether the gas spring must lift a lid, hold it open, reduce closing speed or balance a moving panel. Standard lift gas springs extend automatically and are widely used on machinery covers, vehicle hatches, cabinets and industrial equipment. Lockable gas springs are better when the load must stop at an adjustable position. Dampers control speed but are not intended to carry the full static load.

2. Calculate the required gas spring force

The load weight is only the starting point. The decisive factor is torque around the hinge. A practical initial calculation is: required extension force equals load force multiplied by the horizontal distance from the load center of gravity to the hinge, divided by the effective perpendicular distance from the gas spring force line to the hinge. When two gas springs are used, divide the theoretical total by two.

Add a reasonable margin for friction, seal resistance and unfavorable geometry near the closed position, but avoid excessive force. An oversized gas strut can distort the lid, overload hinges and make closing difficult. A prototype test is recommended before final production.

3. Select extended length and stroke

Extended length is normally measured from the center of one end fitting to the center of the other. Stroke is the rod travel between extended and compressed positions. Confirm both dimensions from the actual mounting points, not only from the free space around the product. The gas spring must not bottom out before the lid reaches its mechanical stop, and it should retain a small travel reserve at both ends.

For compact applications, our mini gas spring range supports small-diameter designs. Different tube and rod combinations can be customized according to force, stroke and installation envelope.

4. Check mounting geometry

Mounting position determines the real opening force curve. A gas spring installed farther from the hinge generally produces more torque, while a position too close to the hinge requires higher nominal force. Check interference throughout the complete motion path. Ball sockets tolerate limited angular movement; rigid clevis joints require better alignment. Side loading on the piston rod should be avoided because it increases seal wear and can shorten service life.

5. Install the rod downward where possible

For conventional gas springs, a rod-down orientation in the closed or resting position helps keep the internal seal lubricated and supports smooth end-of-stroke damping. Protect the piston rod from paint, welding spatter, dust, scratches and impact. Never clamp the polished rod with pliers. Use the correct brackets and tighten the end fittings without twisting the cylinder body.

6. Consider temperature, corrosion and cycle life

Gas pressure changes with temperature, so extension force will be higher in hot conditions and lower in cold conditions. Tell the manufacturer the real operating temperature range, outdoor exposure, humidity and chemical environment. Stainless steel, protective tubes or special surface treatments may be appropriate for corrosive applications. Cycle frequency and opening speed should also be specified because occasional cabinet use is different from continuous industrial operation.

7. Information needed for a reliable quotation

• Load weight and center-of-gravity position
• Lid dimensions and hinge location
• Required opening angle
• Available mounting points
• Extended length and compressed length
• Required stroke and estimated force
• Quantity, operating temperature and cycle frequency
• Preferred end fittings and material

Common gas spring selection mistakes

The most common errors are choosing only by appearance, copying a force value from another application, ignoring the hinge moment, allowing the gas strut to act as the mechanical stop, and installing the rod where it can be contaminated. These mistakes can cause weak support, difficult closing, bent brackets or early leakage.

Conclusion

A reliable gas spring solution comes from matching force and geometry rather than selecting a catalog size in isolation. Longxiang can review drawings, mounting dimensions and operating conditions to recommend a suitable gas spring or gas strut configuration. For special positioning requirements, see our lockable gas spring products, or contact us with your application details for a customized selection.