By Josh Cosford, Contributing Editor
If you didn’t already know, I work for a company that manufactures hydraulic cylinders. A common question from customers is, “What is the life expectancy of your hydraulic cylinders?” My response is often to take a deep breath and then sigh because the correct answer is never straightforward. The salesman in me likes to respond with “indefinitely” but is always followed up with “depends.”
I like to compare the longevity of hydraulic cylinders to that of personal vehicles. It’s common knowledge that when you properly care for your car, it can last indefinitely. Timely oil changes, dealer-recommended service intervals, regular cleaning and some tender loving care are what separates the Boomer from the ’62 Impala running 500,000 miles from the Zoomer calling the scrap yard to collect $500 for their ’08 Corolla that died at 120,000 miles.
I would estimate that the majority of cylinders we sell are less than a couple of grand investment cost, so one might think it’s easy to forsake a cylinder compared to an exponentially more expensive vehicle. For what it’s worth, we sell many cylinders more expensive than what is the mind-blowing, average new vehicle price of close to $50k, but it’s not really the point. Some cylinders are installed on machines costing many multiples of that new car average, and those machines produce revenue for the company many times than what that machine costs as well. The point is that hydraulic cylinders are essential in their roles and should be treated as the tools they are to create revenue for your company.
You want all your hydraulic cylinders lasting as long as possible, and being mindful of what makes a cylinder reliable spells the difference between a Temu rate of failure and Toyota Land Cruiser dependability. Anyway, enough with the fluffy metaphors; you want facts on actual cylinder lifespan.
When treated well, there’s no reason your cylinders shouldn’t last twenty years or longer as long as they were built well to start. But because the primary components are various forms of metal, and all the wear surfaces offer replaceable parts, there’s no reason a cylinder shouldn’t last the life of the machine.
Let’s assume that the head, cap and tie rods never need replacing. That leaves the piston rod and barrel, both of which sometimes do wear. However, both these items can be refreshed easily with an application of chrome. The bushing is a wear item but requires replacing less frequently than the seals and wear strips. Finally, so long as the wear strips are replaced as required and the tube is kept within spec, the cast iron piston should also last indefinitely.
Just as with all hydraulic components in your system, high quality filtration prevents excessive wear of the sealing package. Because cylinders reciprocate, any particles within the oil may score across the rod to barrel, damaging not only the seals but also the rod and tube. As pressure rises, particles are able to push through gaps with more vigor, which is why high pressure systems should employ extra-fine filtration.
And finally, we cannot ignore the design and installation aspects of the cylinder within the machine. The nature of the forces on the rod, the column strength of long cylinders, the quality of the wiper seal, and prevention of side load forces all play a role in reliability. It doesn’t matter how high quality the cylinder is when its subjected to abuse – it’ll fail prematurely.
Hydraulic cylinders are work horses designed with a high safety factor to prevent operation at the cusp of failure. They’re essentially overbuilt for their purpose, and if they’re provided the respect they deserve, they will last a lifetime.
Filed Under: Components Oil Coolers, Cylinders & Actuators, Engineering Basics, Technologies
