Gas Springs

About Gas Springs and Gas Spring Manufacturers, Including: Carbon Gas Springs, Dampers & Stainless Steel Gas Springs.

Gas springs may be referred to as gas props, shocks, dampers, struts or lifts, and they utilize compressed, high-pressure gas to exert a force for extension. The gas is located within a cylinder, and is compressed by a piston and piston rod. There is high pressure exerted on the piston, which is firmly fitted against the rod, and this causes friction when the gas spring is compressed or extended. Oil runs through the piston for smooth and controlled movements, allowing the springs to control the motion and speed of what they are attached to. Nitrogen is the most common choice for gas springs because it is a neutral gas and will not explode when it comes in contact with oil in high-pressure situations. Gas springs absorb or dampen through compression or extension.

There are numerous applications for gas springs. Gas spring manufacturers design springs for lifting, lowering, moving, rigid or elastic locking, seat height adjustment, hydraulic vibration damping and more. They are used in automobiles: tailgates, hoods, trunks, sunroofs and steering columns. They are used in tanning beds, fitness equipment, copiers, physician’s chairs, wheelchairs, stools, hospital beds, roof windows and awnings. Service and noise protection panels can be opened and closed by gas springs. When selecting a gas spring for an application, some things to look at are maximum cycles per minute, extended length, maximum force, compressed length and absorber stroke. Diameters of the cylinder and rod, as well as the mounting and body material of a spring are other important physical features to take note of. Gas spring manufacturers can use a variety of mounting options: ball and socket, clevis, eyelet, rod end, threaded, bumper or rod end unattached, and tapered end. Body materials may be stainless steel, thermoplastic, aluminum, black nitrate or steel.

An advantage of gas springs over mechanical springs is the definable speed curve, which allows for a comfortable and damped adjusting movement, and there are innumerable adjustment options. The curve is extremely flat and has an almost linear characteristic, which allows a comfortable adjustment or pivoting movement. This allows gas springs to improve the performance and ergonomic factors of the products in which they are used. In the area of gates and doors, gas springs are a better option than standard closers because they allow for the gate or door to move slowly, so as not to injure anyone and to keep noise levels down. They also will most likely last as long as the products they are on.

Some new developments from gas spring manufacturers have been made. One new development is gas springs that have temperature compensation with thermally actuated valves that close the main orifice, so they can work well at all temperatures. Gas springs are being used in automobiles to better continuously position the trunks and hoods, and some have started using black nitrate instead of chrome or stainless steel because it is more corrosive-resistant than chrome and less expensive than stainless steel.

Types of Gas Springs

• Blocking gas springs have a valve that permits the flow of a pressurized fluid between two compartments of a cylinder cavity separated by a piston. The piston rod is blocked during inward movement by a predetermined force applied to the piston rod.
  
• Carbon gas springs have carbon steel bodies, making them useful in rough temperature and chemical environments.
  
• Combination gas springs are used to get specific characteristics from different types of gas springs; they have different body and gas spring rod combinations, and are either combined in a parallel or serial fashion.
  
• Compression gas springs have a rod that is compressed into a cylinder, and when the compression is removed, the rod extends. These springs cover a large range of forces and strokes and are the most commonly used gas spring
  
• Dampers are able to prevent or stop oscillations or vibrations.
  
• Extension gas springs have the damping and shock absorption occurring as the rod extends from the cylinder.
  
• Gas springs utilize a cylinder, which contains compressed gas, and a piston to exert a force.
  
• Locking gas springs use a mechanism that allows the rod to be locked at any time by the actuation of a plunger extending from the rod: when the plunger is released the rod locks its position, when the plunger is pushed down the rod moves normally.
  
• Micro gas springs are small in size and have low force, so they are very versatile.
  
• Nitrogen gas springs have lower pressure increase than standard gas springs, and they have consistent, balanced and adjustable force, with more force per area than other springs.
  
• Stainless steel gas springs are used to prevent corrosion on the gas spring rod, which leads to the early failure of gas springs.
  
• Tension gas springs, or traction springs, retract instead of extend and the piston rod stays in a closed position, moving opposite of other gas springs. Used to keep doors, hatches, lids, etc. closed.

Gas Springs Terms

Compressed Length – minimum length of the spring’s shock.

Damping – is gained while regulating the flow of gas through the valve at the orifice of a gas damper piston, it creates a cushioning affect that slows the mechanism before it extends fully.

End Fittings – are used to attach the gas spring to the item it will be controlling, mounting brackets may also be used. There are different options for multiple applications and purposes.

Extended Length – maximum length of gas spring when it is fully extended.

Force – measured 5mm from full extension of the gas spring, and it is a function of the pressure in the cylinder acting on the cross section of the rod. The larger the diameter of the rod, the lower the force.

K-Factor – ratio of compressed force to extended force, compressed force being always larger than extended force.

Piston – a cylinder or disk that displaces fluids or moves under fluid pressure within a larger cylinder.