Choosing the Right Hydraulic Cylinder for a Lifting Application

How to determine the right sized cylinder to lift a heavy load?

Determining the right sized cylinder when performing a lift is critical. Whether it is a piece of equipment you need to lift or some other heavy load, if you choose a cylinder that is too small, you will not be able to lift the load and could cause a safety hazard. At a minimum, you may be headed back to the shop to get a bigger cylinder, wasting valuable time.  Choosing a hydraulic cylinder should not be a guessing game, and it saves time and money if you calculate the size you need before you start your job. Figure out the load capacity of your cylinder before you start your lift attempt, and you’ll be successful every time. A simple calculation ensures that your hydraulic lift can tackle your lifting challenge, and it elevates the safety surrounding the lift. It’s a win-win situation, and the time spent calculating the size of a hydraulic cylinder needed to lift effectively will save you time and help you to get your job finished as efficiently as possible.

 

How to Figure the Size of Hydraulic Cylinder You Need to Lift a Load

 

Step 1: Find out how much you are lifting. You need to know the approximate weight of the item you are lifting. The more accurate, the better. If you are estimating weight, overestimate! You don’t want the lift to be a failure. You also don’t want to just barely meet the load capacity of the cylinder, as any unexpected change or shift could cause the cylinder to stall in the middle of its cycle. Figuring out how much you are lifting is crucial in deciding which hydraulic cylinder to use.

 

Step 2: Know your available pressure. The hydraulic pressure from your pump must be sufficient to provide enough pressure to act on the cylinder and lift the required load. The size of your cylinder won’t matter if you aren’t able to supply enough pressure. At PowerX International, we specialize in 10,000 psi (700 BAR) hand pumps, air/hydraulic pumps and electric pumps.  Therefore, the following examples will be based on 10,000 psi.

 

Step 3: Find out how many “points” you are going to lift the load.  Some lifts are a simple one-point lift, but sometimes it is not feasible to balance a load with only one point, thus requiring two or more points.  Once you know the amount of lift points and the total load you are going to lift. You can calculate the size of the cylinder(s) needed by dividing the total load by the amount of points.  For example, a 100 ton load with one lift point would need at least a 100 ton cylinder while that same load with four lift points would require four 25 ton cylinders.

 

Step 4: Always have a safety factor.  Most loads are never exactly what they appear to be and to be safe, you would never want to be right at the limit of the cylinder’s capacity.  Because of this, it is recommended that at a minimum you use a cylinder that is 125% of the load capacity needed.  And, if possible, you should have a cylinder (or cylinders) that can handle a load 1.5 times to 2 times larger than the load you are trying to lift.

 

LIFT EXAMPLE

Customer needs to lift a 5” concrete block with a weight of 160,000 lbs. Load shape is a rectangle 10’ x 20’ where force needs to be applied to each corner.

Load, Lifting Points, Cylinders

Load 160,000 lbs. = 80 Tons

4 lift points 80 Tons/4 cylinders = 20 Ton capacity each cylinder

Utilizing a 25% factor we will need 25 Ton capacity cylinders

25 T capacity x 4 cylinders = 100 Ton capacity system @ 10,000 PSI

Therefore, the correct cylinder force needed is four (4) 25 Ton cylinders.

 

Lastly, it is important to keep your hydraulic cylinders clean and well-maintained. One common reason for hydraulic cylinder failure is that the seals become dry, dirty, and damaged. Make sure you are inspecting your cylinders prior to use, so you don’t end up with a non-working hydraulic cylinder when it comes time to lift.

 

Measure First, Lift Once

There’s an old adage in carpentry that says, “Measure twice, cut once.” A similar notion can be applied to choosing the right size of cylinder for any lifting job. If you have been using hydraulic cylinders for many years and have repeat jobs that make you sure the cylinder will work, that’s great. However, when you are dealing with heavy loads, time and money is lost if you are off the mark. It is a better practice to measure and calculate the size of the cylinder needed. This way, you won’t have to go back for different cylinders if yours isn’t big enough. Plus, your lift won’t fail midway through the job.

 

Another way to determine the right sized hydraulic cylinder for your lift is to view or download our catalog. You can also call us and one of our knowledgeable representatives will help you find the right PowerX hydraulic cylinder for your application.

 

PowerX International has the expertise to help you with your lift requirements and the high quality hydraulic cylinders, hydraulic pumps and hydraulic systems to get the job done. Contact PowerX at +1.414.988.6202 for all your high pressure hydraulic needs.