Gas springs, also known as gas struts or gas dampers, are crucial components in various applications, from car hoods and truck tailgates to medical equipment and industrial machinery. Accurately measuring them is essential for proper selection, replacement, and repair. This guide covers the key measurements needed and how to take them effectively.
What Measurements Are Important for Gas Springs?
Several critical measurements define a gas spring's characteristics. Understanding these will help you select the correct replacement or specify the right spring for a new application. The key measurements include:
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Extended Length: This is the total length of the gas spring when fully extended. Measure from the center of the eyelet (or mounting point) at one end to the center of the eyelet at the other end.
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Compressed Length: This measurement is taken when the gas spring is fully compressed. Again, measure from the center of one eyelet to the center of the other.
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Stroke Length: This is the difference between the extended and compressed lengths. It represents the distance the piston rod travels during operation. Simply subtract the compressed length from the extended length.
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Body Diameter: Measure the diameter of the cylindrical gas spring body, excluding any mounting hardware.
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Eyelet Diameter & Type: Note the diameter of the eyelets (the mounting points) and their type (e.g., ball stud, clevis pin, threaded stud). The type is crucial for compatibility. Take note of any specific features of the eyelets that might affect compatibility.
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Force (or Push/Pull): This specifies the amount of force the gas spring exerts at a given extension. This is usually measured in Newtons (N) or pounds-force (lbf). This is typically found on a label on the spring itself, but if you are replacing a spring, take the information from the original.
How to Measure Gas Springs: A Step-by-Step Guide
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Safety First: Before you begin, ensure the gas spring is properly secured. If possible, release the pressure by gently compressing the spring. Always wear appropriate safety glasses. Gas springs can contain high-pressure gas and can cause injury if improperly handled.
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Gather Your Tools: You'll need a measuring tape (preferably a flexible one for accurate curved measurements), calipers (for precise diameter measurements), and a notebook or digital device to record your findings. A camera can also be useful for recording visual details like eyelet type and any markings.
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Measure the Extended Length: Fully extend the gas spring and carefully measure the distance from center of eyelet to center of eyelet.
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Measure the Compressed Length: Gently compress the gas spring fully (with caution) and measure the distance from center of eyelet to center of eyelet.
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Calculate the Stroke Length: Subtract the compressed length from the extended length.
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Measure the Body Diameter: Measure the diameter of the gas spring body at its widest point, ensuring the tape measure is perpendicular to the body.
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Measure and Identify the Eyelets: Carefully examine the eyelets. Measure their diameter, and take note of their type and any unique characteristics. Note if they are threaded, if there are specific mounting hole shapes or if they are a specific type of clevis pin.
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Determine the Force: Check the gas spring for any markings that indicate the force it exerts. Often the information will be labeled in Newtons (N). If you do not have this information, consult the manufacturer's documentation or the supplier if this is a replacement for an existing spring.
What if I Can't Access the Force Rating?
If you cannot find the force rating on the spring itself, obtaining a replacement becomes more challenging. You might need to contact a gas spring supplier, providing them with all other measurements. They may be able to identify the correct force rating based on the other dimensions. An alternative approach, if possible, is to measure the force directly using a spring testing device.
Frequently Asked Questions (FAQs)
What tools do I need to measure gas springs accurately?
You'll need a flexible measuring tape, calipers for precise diameter measurements, and a notebook to record measurements. Safety glasses are crucial.
Can I measure gas springs while they're installed?
It's challenging, and potentially unsafe, to accurately measure the length and stroke while installed. Ideally, remove the gas spring for the most accurate measurements.
How do I interpret the force rating on a gas spring?
The force rating indicates how much force the spring exerts at a specific point in its stroke. This force is usually given in Newtons (N) or pounds-force (lbf). The higher the number, the stronger the spring.
What happens if I use the wrong gas spring?
Using an incorrectly sized or rated gas spring can lead to improper operation, damage to connected components, or even safety hazards. It's crucial to use the correct size and force rating.
By following these steps and understanding the significance of each measurement, you can accurately measure gas springs for effective selection, replacement, and troubleshooting. Remember, safety is paramount throughout this process.
