Technical Article

How To Start A Smarter Maintenance Plan for Fluid Power Systems

January 03, 2022 by Jeff Kerns

Smart connected devices are providing savings and increasing productivity for companies. Let's dive into using connected devices for hydraulic and pneumatic power solutions.

Hydraulic and pneumatic systems could save billions a year—if designed to be smarter.

The following will offer a way to start a preventative maintenance plan for hydraulic and pneumatic applications to help you focus on objectives without getting distracted by fancy new tools.

Even with electric motors offering feedback, positioning, and controls, fluid power is still prevalent in multiple industries due to its power density, simplicity, and cost. Because of these factors, companies are not trying to replace fluid power but make the systems smarter. 


Valuable Data Drives Maintenance Objectives

Multiple smart products on the market can offer data and monitoring, but don’t be distracted by easy access to data. Making everything smart might only accomplish inundating maintenance plans.

Remember, correlation does not imply causation. Start small by targeting and quantifying pain points. A reasonable way to know where to find these pain points is to ensure managers talk to technicians who regularly interact with the machines. Technicians and engineers will understand what information has value to the operation. 

Start with clear objectives. Then pinpoint locations and the type of data that will add the most value to accomplishing those objectives. Communicating with the people who interact with that system each day makes it possible to find problem areas or solutions closer to the root cause.

Establishing a robust maintenance plan can have two main parts: preventive maintenance and predictive maintenance. By incorporating both, it is possible to:


Eaton configuring connected products

Figure 1. Eaton LifeSense. Image used courtesy of Eaton


The Basics: Preventive vs. Predictive Maintenance

Preventive Maintenance for Fluid Power Systems

Other innovations provide options to monitor, set up, and configure connected products. Figure 1 shows Eaton LifeSense, but others exist, such as Parker Hannifin’s SensoNODETM and Sun Hydraulics XMD hydro electric driver. 

Preventive maintenance normally uses knowledge about the machine to determine when it is a good time to service equipment or replace parts. For example, a maintenance manual might suggest replacing a timing belt every 30,000 hours of operation. But, workers who see the machine every day observe the belt's condition to determine if it can last longer or if it needs to be replaced sooner.

Suppose a part’s operation is prolonged due to its observed condition. In that case, a technician might become busy and forget to check it regularly or remember the last time equipment was serviced or inspected. 


Predictive Maintenance for Fluid Power Systems

No matter how well a preventative maintenance plan is, predictive maintenance coupled with a connected monitoring device adds value to operations. Adding predictive maintenance to back up a preventative maintenance plan can ensure service is done when needed, not when assumed.

Additionally, data history will ensure any maintenance prolonged due to an observed condition is not forgotten. 

Having a smart connected device isn’t providing a universal solution. A leading cause of failures is overlooking fluid levels and filters. Technicians should still check hoses and fluid levels regularly. Additionally, leaks and resistance in a system can be costly, but could go unnoticed if everyone is simply waiting for notifications to alert them.

In a pneumatic system, leaks can be expensive. A technician might not notice if a compressor is performing more cycles than normal, especially if the compressor is far from workers.


Festo motion terminal

Figure 2. Festo's Motion Terminal with pneumatic abilities. Image used courtesy of Festo


Festo's Motion Terminal is equipped with "smarter" operations, such as the ability to slow a pneumatic rod before hitting its maximum or minimum stroke. This prolongs the cylinders' lifecycle and reduces maintenance overall.


Smarter Systems and Smarter Workers

According to Swagelok, a company that develops and provides fluid system products, “A single leak in a quarter-inch compressed airline can cost a facility anywhere from 2,500 USD to more than 8,000 USD per year.” The report also mentioned how poorly designed and maintained compressed air systems might be costing the U.S. industry up to 3.2 billion USD annually.  

Connected devices are working on detecting leaks and system health. Providing data such as fluid viscosity, temperature, flow rate, levels, and pump operation to an experienced technician will likely create a better idea if leaks, plugged filters, etc., are causing excessive wear in a system.

Software might help provide insight into maintenance concerns, but it is important to have smart systems and smart technicians. If a system requires more maintenance than the OEM's manual, or repairs are increasing in general, it could be assumed there is something else acting on the system. 

External forces often cause fluid degradation. If a smart device can’t sense what is happening outside the fluid, it will not find the root cause of failures or increased maintenance.

This is why a smart maintenance plan should always start by connecting your people first. 

Do you have a smart maintenance plan in place?

Look out for a future article on utilizing smart sensors in fluid power systems.