Model FF-2500 Proportioning Unit
36
25942-1, Issue 4
Isocyanate Pump Lubricant
To ensure that the pump lubricant will do its job, check its condition daily. Change the
lubricant before it becomes a gel, or when its color darkens as it becomes diluted with
isocyanate.
Gel formation is due to moisture absorption by the pump lubricant. The time interval
between changes due to gel formation will depend on environmental conditions in which
the equipment is operating.
Discoloration of the lubricant is due to continual seepage of small amounts of isocyanate
past the pump packing during operation. However, if the packing within the isocyanate
pump is functioning properly, pump lubricant replacement due to discoloration should
not be more frequent than 3 or 4-week intervals.
To change the pump lubricant, proceed as follows:
1. Stop the proportioning unit with the pump yoke at the top of its stroke. Switch OFF
the pump switch and disconnect the air from the proportioning unit.
2. Remove the pump lubricant from the cup by dipping a dry rag into the cup to absorb
the contaminated liquid. Wipe the cup and pump shaft clean. Remove any hardened
material from the shaft, taking care not to scratch the shaft.
3. Fill the lubricant cup with fresh pump lubricant to about 3/4 inch below the top.
