Beware of High Grease Pressure
Standard lever-action grease guns are capable of producing very high grease pressure. Many of these grease guns can produce pressures up to 7,000 psi. If grease were to be injected into bearings at these pressures, damage could result. Grease could surge through clearance gaps into other parts of equipment. Roller separation cages could be pressed into bearing surfaces. Damage to bearing shields or seals could also result. Grease pressures should be kept below 500psi to avoid doing damage.
Know Your Volume
Bearing lubrication specifications will often tell you how many ounces or grams of grease should be injected during lubrication. It’s fairly straightforward to pump a known number of strokes on a grease gun and measure the volume of grease. This tells the technician how many strokes are required to inject each ounce or gram of grease.
Single Grease Port vs. Dual Grease Ports
Some larger bearings have a removable plug opposite the grease fitting. Removing this plug allows old grease to be flushed out of the bearing when adding new grease through the other port. Taking advantage of this second grease port will require installing two grease fitting extension hoses. An explanation of dual line systems can be found here.
Greasing a Bearing by “Feel”
In the real world, bearing grease pressure is usually controlled by feel. As long as the lubrication technician injects grease into the bearing slowly, he can feel when the pressure in a bearing starts to increase. A bearing with voids will not be under pressure. As soon as the bearing is full of grease, the bearings internal pressure will rise dramatically. The technician can easily feel this increase in pressure through the grease gun handle. As soon as this pressure increase is felt, the technician should stop applying grease – even if he is mid stroke.
Grease Extension Hose Pressures
What are the working and bursting pressures of our grease relocation lines? Our 1/8″ custom-length ready-to-install hoses have a continuous maximum working grease pressure of 2,500 psi with a minimum bursting pressure of 10,000 psi. These pressures far exceed any grease pressure that will be found in the field.