Lubrication Checkup: Grease Delivery Lines

Symptom:

“Recent fork-lift damage to one of our machines affected several steel grease-delivery lines connected to one of the Trabon automatic-greasing system’s lube blocks. Can I rely on the lube pump to pre-fill the replacement lines?”

Diagnosis:

A typical Trabon centralized grease-lubrication system consists of a pump assembly connected to a number of progressive divider distribution blocks. Each block has one line in and numerous lines out, connected to either a secondary distribution block or direct to the lube points. Each discharge point on a block could be feeding a different size bearing requiring differing amounts of grease. Therefore, the system and blocks must be custom engineered and built prior to assembly on the machine, and all lines filled prior to use. When a charge of grease is pumped into the block, the pistons actuate progressively, one after another, as the lubricant moves through the porting in the block and the correct amount is delivered to each bearing point.

Prescription:

Remember that you are dealing with a hydraulic system. Its lines must be pre-filled prior to startup so that small, apportioned amounts of grease discharged at the block can simultaneously hydraulically push an equal amount of grease at the line end into the bearing. Using the lube pump to fill lines will take a very long time due to the apportioning aspect of the system. In the process, some bearings could fail as a result of lube starvation.

All block discharge points have the ability to be piped into the side of the block (the most common arrangement) or into the front. Both discharge exits are connected, and the unused one will be plugged. Simply undo this plug and screw in a regular grease nipple. Next, undo the corresponding end of the grease line at the bearing point, connect a grease gun and hand-fill the line.

Once grease appears at the bearing-point end, reconnect the line, take out the grease nipple and re-plug the block. Repeat for all delivery lines and you are good to go!