Maintenance
42
Pump Lubrication System
Check the condition of the ISO pump lubricant
daily. Change the lubricant if it becomes a gel,
its color darkens, or it becomes diluted with
isocyanate.
Gel formation is due to moisture absorption by
the pump lubricant. The interval between
changes depends on the environment in which
the equipment is operating. The pump lubrica-
tion system minimizes exposure to moisture,
but some contamination is still possible.
Lubricant discoloration is due to continual
seepage of small amounts of isocyanate past
the pump packings during operation. If the
packings are operating properly, lubricant
replacement due to discoloration should not be
necessary more often than every 3 or 4 weeks.
To change pump lubricant:
1. Relieve pressure, page 35.
2. Lift the lubricant reservoir (LR) out of the
bracket (RB) and remove the container
from the cap. Holding the cap over a suit-
able container, remove the check valve and
allow the lubricant to drain. Reattach the
check valve to the inlet hose. See F
IG
. 7.
3. Drain the reservoir and flush it with clean
lubricant.
4. When the reservoir is flushed clean, fill with
fresh lubricant.
5. Thread the reservoir onto the cap assembly
and place it in the bracket.
6. Push the larger diameter supply tube (ST)
approximately 1/3 of the way into the reser-
voir.
7. Push the smaller diameter return tube (RT)
into the reservoir until it reaches the bot-
tom.
8. The lubrication system is ready for opera-
tion. No priming is required.
Important:
The return tube (RT) must
reach the bottom of the reservoir, to
ensure that isocyanate crystals will set-
tle to the bottom and not be siphoned
into the supply tube (ST) and returned
to the pump.
F
IG
. 7. Pump Lubrication System
LR
RT
ST
RB
ti9911a
ti9887a
LR
ST
RT
