Sterlco 2016C (Former Compact Series) - Manual (Page 29)

COT-C Series Hot Oil Portable Temperature Control Units Page 29
Returning Fluid To Tank (With Manual Vent Valve)
If the unit is to be moved from one process to another (i.e. mold
changes, etc.), the following steps must be taken to drain the mold
and process lines. Note that this is just the opposite of unit start
up/air purge:
1. Cool fluid to 100 degrees °F maximum.
2. Open the Vent Valve to allow in fresh air into the pipes.
3. Turn the Pump Rev|Off|Fwd switch to Off.
4. Turn the Pump Rev|Off|Fwd switch to Rev. The pump
will then run in reverse, drawing fluid from the mold and
lines, and into the reservoir tank.
5. Watch the sight glass to prevent overflow of the
reservoir tank.
If it appears that the tank may overfill, connect a line from the
FILL port of the reservoir tank to a clean auxiliary container.