Lubrication Checkup: How to Correct SPL Failures

Symptom:

“We use programmable single-point lubricators for our hard-to-reach equipment bearings and regularly perform preventive-maintenance (PM) checks to ensure the units are working properly. Those PM checks recently detected that a number of newly installed units have failed to deliver any grease in weeks, despite a full charge of grease and the unit displaying active status. Is the unit at fault?”

Diagnosis:

All programmable single-point-lubrication (SPL) devices are similar in that they are predominantly designed to dispense grease into a single lubrication point, in a continuous manner, for up to two years on a single charge of lubricant. Programmable units are primarily battery-operated, self-contained units designed to operate using an electro-mechanical discharge pump or an electro-chemical reaction chamber that forces gas into a hermetically sealed expandable bellows chamber and “pushes” grease into the lube line.

Any of the following situations can cause the unit to appear functional in a “stalled” state of operation:

1. The lube line carrying grease from the unit to the bearing point is blocked with debris or partially collapsed, causing line back pressure that will can stall the unit.
2. The bearing has turned in the housing, creating a line blockage.
3. The unit is operating outside in cold weather using a heavy #2 grease.
4. The unit is set up on the longest delivery settings and has not been set up correctly prior to installation.

Prescription:

ALWAYS read the manufacturer’s instructions before using any SPL device. Many units are required to run on their shortest delivery cycle (full throttle delivery) for up to 12 or more hours to ensure the unit is working properly prior to set up and installation. And ALWAYS check that you have the correct NLGI numbered grease for the ambient operating temperature.

Moreover, when installing an SPL unit, make sure the delivery line has not been damaged or crimped in any way.