Technical Information

Great care must be taken to ensure that no damage occurs to the rod which would damage the internal seal.

Safety & Installation

SAFETY & INSTALLATION

IMPORTANT PLEASE READ CAREFULLY

Great care must be taken to ensure that no damage occurs to the rod which would damage the internal seal, specifically:

DO NOT SCRATCH, DENT, CHIP, BEND OR PAINT THE ROD, ROD DAMAGE WILL INVALIDATE THE WARRANTY

On gas springs there is a seal where the rod enters the Cylinder. For correct working, this seal must be lubricated by the oil within the body. For this reason, Gas springs must be:

STORED WITH THE ROD DOWN
FITTED WITH THE ROD DOWN
GAS SRPINGS ARE PRESSURIZED WITH INERT INTROGEN GAS UNDER HIGH PRESSURE. See Material Safety Data Sheet on Quality Certifications Page

DO NOT PUNCTURE OR INCINERATE

When gas springs are fitted to support loads, where people are in danger should the load fall, care should be exercised with regard to end fitting suitability, mounting position strength and whether a secondary locking mechanism should be employed.

Gas Springs will not tolerate side load forces, wherever possible, ball joints should be used to take up any potential side loads. Ensure that the mounting positions are in line and that any flexing of the load does not induce side load forces.

It is essential that the gas spring end fittings are fully screwed home when in use. Failure to fully screw home the end fittings severely weakens the springs. Under no circumstances should the end fittings be unscrewed to increase the length of the springs. Gas Spring Spacers are available for slight adjustment of the length. Enquire with the Sales department.

Gas springs should not be operated more than 3-4 times per minute. Faster rates of operation will lead to excessive heat build-up that will lead to internal seal damage and voiding of the warranty.

When using Gas Springs in very dusty or hazardous environments, a Dust Boot Should be fitted to the Rod end that will keep the Rod Clean at all times. Enquire with the Sales Department about Dust Boots.

When possible, physical stops should be employed limiting the extended and compressed lengths of the spring to within 5mm of their optimum values, in other words ensure that undue force is not applied to over compress or overextend the springs.

The operating temperature range of our Gas Springs is -20 Degrees Celsius to 80 Degrees Celsius approximately.

How Gas Springs Work

HOW DO GAS SPRINGS WORK?

ALL YOU NEED TO KNOW!

THE GAS SPRING

A gas spring consists of a Steel Nitride Coated rod attached to a piston moving within a sealed cylinder containing nitrogen Gas at high pressure. Output forces are the result of the differential between the pressure in the cylinder and atmospheric pressure outside the cylinder acting on the cross-section of the rod. As the piston rod is introduced into the cylinder (compression stroke), the internal pressure increases according to the volume of gas displaced by the rod. This increase in Force or K-Factor is normally 5% – 50%. In comparison to mechanical springs, gas springs are an almost constant force.

Because they operate on simple pressure differentials, gas springs will perform as well in the vacuum of space as they do on land.

GAS SPRING MOUNTING INSTRUCTION

All gas springs contain a small amount of oil to lubricate the main seal and rod. This oil also provides end of stroke damping. If standard gas springs are operated and mounted in a rod-up orientation, fluid cannot reach the main seal or rod which leads to excessive seal wear and reduced life. It is recommended that standard gas springs be mounted rod down at least 30 degrees off horizontal.

GAS SPRING & STRUT FORCE CALCULATIONS

HELPING YOU FIGURE IT OUT!

Gas spring force calculation is normally designated as P1 which is the force measured 5 mm from full extension in the extending direction. Force is a function of the charge pressure in the cylinder acting on the cross section of the rod. The smaller the diameter of the rod the lower the force at the same pressure. For example, a spring with a 10 mm rod charged to a pressure of 70 Bar will yield a P1 force of 50KG. while a spring with a 6 mm rod charged to the same pressure will yield a force of only 18KG.

Compressed force is referred to as P2. P2 is measured 5 mm from full compression in the extending direction and will always be greater than P1.

WHY SHOULD SPRINGS BE USED ROD-DOWN?

In order to keep the rod seal lubricated, a small amount of oil is used in every gas spring. When used rod-down, the oil is kept in contact with the rod seal which improves the sealing properties and ensure the seal will never become dry.

For this reason, one of the basic recommendations when incorporating gas springs in your application is to make sure they are used at an angle of less than 60 degrees from the vertical.

The oil used in the gas spring is also useful to obtain a high damping effect on the last few millimetres of the stroke. If the gas spring was not used rod-down, the piston would not have to go through the oil at the end of the extension and no damping effect would occur.

Do's and Dont's

RECOMMENDED FOR GAS SPRINGS

PLEASE DO …

Use standard gas springs rod-down, i.e. the spring should be mounted so that it spends most of its life in a rod-down position, within 60° of vertical, thus ensuring the seal stays lubricated.
Try to use ball joints to help avoid side load forces. If eyelets or fork clevises are used, ensure a loose fit to allow for lateral movement. Always use the correct size of Clevis pins.
Ensure that the end fittings are in line so that side load forces are not applied as a result of misalignment. If this is not possible, use Angled End Fittings. Enquire with the sales team on angled ends.
Try to use shorter springs close to the hinge rather than longer stroke springs away from the hinge.
Provide physical stops to limit the spring’s extremes – i.e. ensure that no undue force is applied, which might over compress or overextend the spring.

NOT RECOMMENDED FOR GAS SPRINGS

PLEASE DO NOT…

Scratch, dent, chip, bend or paint the rod.
Apply side loads.
Never Attempt to recharge Gas Springs
Puncture or incinerate it.
Lubricate it.
Fast cycle it – typically no more than 3-4 times per minute.

SAFETY & STORAGE

When gas springs are fitted and safety is a key factor, special care should be exercised with regard to fitting suitability, mounting position strength and whether or not a secondary locking mechanism should be employed. Store in rod-down condition.

How Are Gas Springs Different?

DIFFERENCES BETWEEN GAS STRUTS, SHOCKS & SPRINGS

Know The Differences To Know Your Product

Gas springs are sometimes referred to as gas struts or gas shocks. These terms are more or less interchangeable in the gas spring industry. But their differences are important when understanding how gas springs work and how to use them properly.

GAS STRUTS

A strut is typically a rigid rod that provides structural support to the object it is mounted on. It may allow for minor movement but a gas strut is not intended as an assist in lifting or moving something like a gas spring is. Gas struts offer outwards-facing support and can be used to keep two other components separate. Gas struts have many applications, including: automobiles, architecture, construction and aircrafts.

GAS SHOCKS

A shock is a term used more commonly for a device meant to absorb vibration or other movement and return something to its original position. It also does not typically provide assistance in lifting like a gas spring will but they are designed to take quick, repeated movements without failure. They provide both force and damping at the same time.

A TRUE GAS SPRING

Note: Gas springs may also be referred to as gas struts, gas props, gas shocks, gas lifts or gas dampers depending on the industry and application.

A true gas spring is designed to be used as a lift assist device to open a door, lid, or hatch. Gas springs can also be used as a counterbalance or motion control device either with or without minor damping. They are not to be cycled more than a few times per minute and must not be over-extended, over-compressed, or shock loaded at a faster rate than they are designed for.

It is important to keep in mind how a gas spring is designed to work and its limitations. If what you need is a product that operates more like the description for a strut or shock then a different product would be needed. Enquire with the Sales Team on selecting the right product for your application.

Struts Africa® Warranty

Struts Africa® Stands Proudly Behind Our Warranty & Product Quality

(Valid in South Africa only). Struts Africa® warrants the listed. Struts Africa® products to the original retail purchaser against functional and/or material defects:

STRUTS AFRICA® provides a 2 year warranty without mileage limitation. The Warranty of STRUTS AFRICA® is limited to the delivery of a new STRUTS AFRICA® product. All claims are first handled by the STRUTS AFRICA® distributor and then honoured by STRUTS AFRICA®.

The reseller/installer will provide the STRUTS AFRICA® distributor with all relevant information such as:

consumer’s name and address fitting or sales dates STRUTS AFRICA® product part number
vehicle identification data proof of purchase documents description of the defect.

In addition: All STRUTS AFRICA® products are developed and manufactured according to original specifications where possible from manufacturers. STRUTS AFRICA® products are a suitable replacement part and not an original Part.

NOT COVERED BY THE WARRANTY

Find Out What Exclusions Affect The Warranty

Regular wear-out.
STRUTS AFRICA® products fitted contrary to application information in the STRUTS AFRICA® catalogue or its subsequent amendments.
STRUTS AFRICA® products which have been modified or damaged by incorrect mounting or incorrect use of the vehicle, contrary to the car manufacturers’ specifications or STRUTS AFRICA’s®.
STRUTS AFRICA® products damaged by mounting on another car than indicated in the STRUTS AFRICA® catalogue or its subsequent amendments.
Gas Springs with damaged piston rod or damaged oil seal due to holding the piston rod with a wrench or pliers instead of the correct tool.
Premature wear-out caused by re-use of damaged mounting parts such as: rubber dirt shields, damaged bump stops, etc.
Damages caused by an accident.
STRUTS AFRICA® products damaged while used in rally or racing sports.
Gas Spring abrasion caused by incorrect mounting.
Reconditioned or recycled STRUTS AFRICA® products.
Defects caused by lack of maintenance or maintenance wrongly executed on the vehicle.

Our Certifications Ensures That We Are Qualified To Give You Expert Advice

(Contact us should you require additional information)

Quality systems & certification

ISO/TS16949:2009: Quality Austria
RoHS Compliant: RoHS & CE Compliance Statement
SGS Certification IEC62321: SGS Certificate 2015
CE Certification: Certificate of Conformity
TUV Certification: Fatique Test