Complaints about poorly performing compressed air tools are quite common at industrial sites. The tools may lack torque, and even stall if any significant load is placed on them. This lack of output could be reducing your production output—and therefore be costing you money.
Many times, the source of the problem is poorly designed supply components: the filters, regulators, lubricators, connectors, hoses and fittings used in transporting the compressed air to your tool are not the correct size. If these are not properly selected, then the tool may receive air pressure that is much lower than its rating, and the result is lower tool performance.
A very easy way to check to see if you have a problem is to rig up a little test jig using an accurate pressure gauge, a T connection, and some quick connect couplers. Place the test gauge in series with the tool and check the pressure. Perhaps your typical system pressure is 100 psi—that is what you would see on the gauge with the tool at rest. Should the feed to the tool be regulated, then you would see the regulator is set pressure. If no air is flowing to the tool there should be no pressure drop in any of the supply components that exclusively feed the tool.
Next, operate the tool. Once there is a flow of air, any pipline restrictions will develop a pressure differential. This will reduce the pressure at the test jig. Observe the pressure and compare it with the initial pressure. If the pressure drops excessively, to levels below the rating of the tool, then you have a problem.
If you are wondering what specific component is causing the problem, then move the gauge upstream and test again. By carefully recording the pressure drop caused by the tool operation you can usually isolate the problem to one or more components.
But what is causing the pressure restriction? Often industrial plants choose to install just one common size of components for every tool and piece of equipment in the plant. But the compressed air flow of different machines and tools can vary widely. A ¼-in. hose may be a good size for a small pneumatic screwdriver, but if applied to a large impact wrench, then poor tool performance results. Carefully investigating each air tool flow demand requirement will allow you to properly size supply components for the low pressure drop required to keep the tool at or above its rated pressure during operation.
Often the components may only need to be sized one larger step up— for example, 3/8-in. components instead of ¼-in. A check of the component pressure differential curves supplied by the manufacturer can be helpful in doing this work.
Many people are surprised to learn how low the pressure drops at their tool. Testing makes you aware of problems and can show if your subsequent upgrades have fixed the problem. Proper sizing of supply components is key here.
Is pressure not the problem? One other thing to consider is tool maintenance. Many people no not realize that many compressed air tools need to be lubricated at regular intervals. This prevents internal wear and helps seal internal moving parts from blow-by leakage. Does your tool require this? Read the manual.
Filed Under: Pneumatic Tips