When designing a cylinder, it is important to consider how much force will be on the piston rod as the cylinder is extending. If too much compressive force is applied to the piston rod in extend, it will cause it to bend and buckle. Consider a coffee stirrer. When placed between two fingers and pushed on, it very easily bends. Now consider a drinking straw. While it might be longer, it also has a larger diameter, thus when placed between two fingers and pushed on with the same amount of force it does not bend as easily. In the same way piston rods will bend when the force to rod diameter ratio becomes too large. Several factors contribute to the force, and associated cylinder pressure, when this bending will begin to occur. These factors include bore size, rod diameter, mounting style, length of stroke and extra plain rod extension, and even rod material.

A critical decision to make when designing a cylinder is the size of the bore. The bore is the inner diameter of the cylinder tube, which can also be known as the barrel. The bore size, along with the known operating pressure of the cylinder determines the force output of the cylinder. Many hydraulic systems are designed to run at 3000 psi hydraulic pressure, while most pneumatic systems are designed to run at roughly 100 psi.

There are many applications where cylinders are exposed to extreme heat due to environmental conditions. Whether your cylinder is near a bakery oven or hanging above a crucible of molten metal knowing which options are available to handle the heat becomes top priority.

In 1962, E.F. Houghton Co. published A Handbook On Hydraulic and Pneumatic Packings for the fluid power industry. In the opening chapter there is an illustration of a “typical animal hide” which depicted the best parts of the hide that could be fabricated into leather “U” cups, “V” rings, and gaskets to seal fluid power cylinders.

When installed with proper alignment, fluid power cylinders will provide the smooth trouble free performance for which they were intended.  Unfortunately, perfect alignment is extremely difficult, if not next to impossible to achieve. During cylinder operation, any misalignment can impose an eccentric force on the piston rod known as “side loading”.

You know that sinking feeling when you take the first bite of a much needed lunch, the phone rings and you answer to hear the words "We have a problem; it’s a new installation and the tube seals have blown!" With thoughts of catching a snack later in the day, you attend the scene of the crime...

Any piece of equipment operates best when it is used regularly within normal guidelines.

Take for example a classic car; it ran perfectly when you put it away last fall, but something happened during the long winter.

In our experience, the call for more than one mounting feature on a cylinder is by no means a rare event.

We won’t say that all mounts can be combined; as clearly there are some features which would just interfere with each other. For instance, a Front Head (FHF) and a Side Lug (SL) cannot coexist on the same end of a cylinder. What is possible, however, is to have an FHF (Head) mount combined with a Side Lug at the Cap; if that serves a useful design purpose for you.

Ever thought that you have had to go a long way around a design problem to mount a particular component? Here's a hint that might possibly be a ‘quick-fix’ and a help if you're finding yourself in a similar situation.

Sheffer fits tie rod supports to long stroke cylinders to stop the tie rods from twanging like an out of tune banjo - and the design feature does a wonderful job of achieving that aim.