The process of choosing the right hydraulic cylinder for your specific application may seem routine or even repetitive at times, but it's important to maintain a fresh outlook in beginning this process and to always remember to consider several basic components.
1. Consider the Size
Don't be such a bore.
The first key piece of information to consider when choosing a bore size is the operating pressure. The basic operating pressures that are commonly used range from: 500 psi to 3000 psi. These pressures match up with NFPA medium and high pressure cylinders. Knowing the operating pressure you would like to use will help drive the selection of the cylinder bore size.
The second key piece of information needed to select the bore size is the amount of force required for the application. A quick formula for finding the approximate bore size for the extend direction of the cylinder is as follows:
F = force required (lbs.)
P = operating pressure (psi.)
D = bore diameter (in.)
D = F / (.7854 * P)
Typically the resulting bore diameter is rounded up to the next common standard bore size
2. Consider the Mount
Pivoted vs. Straight Line.
Cylinder mounts can be divided into two basic categories: pivoted and straight line. Selecting the right mount for an application mainly depends on the desired movement of the load. Pivoted mounts can be used where a load needs to move through an arc and include mounts such as Trunnion and clevis.
In comparison to pivoted mounts, straight line mounts are used when the load only needs to move in a linear direction and include mounts such as front head flange and side lug. It is necessary to consider the desired movement of the load specific to your application to ultimately determine the type of mount.
3. Environmental Conditions
Is it hot in here, or is it just me?
Knowing where the cylinder is going to operate is important for selecting the appropriate materials, seals, and finishes. The material of the cylinder can be modified to meet specific environmental conditions. A common example, is selecting stainless steel components for corrosion resistance on wash down food production equipment. The cylinder seals can be changed for a variety of reasons, including high or low temperatures or special operating fluids, such as water glycol or phosphate ester fluids. Cylinder finishes can include special metal plating or paint finishes to meet a variety of indoor and outdoor applications.
What other steps would you add to this list? Leave a comment with your thoughts below.
Image credit: Ambro
