Gorman-Rupp Pumps UNIT 608 1347755 thru 1395613 - Manual (Page 13)

OM−01228 UNIT SERIES
PAGE B − 6 INSTALLATION
SUCTION LINES
Position the suction hose as far away as possible
from the discharge hose. The two hoses must be
on opposite sides of the drum.
Suction Line Positioning
The depth of submergence of the suction line is
critical to efficient pump operation. Figure 12
shows recommended minimum submergence vs.
velocity.
NOTE
The pipe submergence required may be reduced
by installing a standard pipe increaser fitting at the
end of the suction line. The larger opening size will
reduce the inlet velocity. Calculate the required
submergence using the following formula based
on the increased opening size (area or diameter).
Figure 12. Recommended Minimum Suction Line Submergence vs. Velocity
DISCHARGE LINES
Siphoning
Do not terminate the discharge line at a level lower
than that of the liquid being pumped. Otherwise, a
siphoning action causing damage to the pump
could result.
Valves
This unit is equipped with an eductor control valve
on the discharge side of the pump. The eductor
has a 3-position valve for vacuum, backflush or
shutoff of the system. Make sure this valve is in the
shutoff position after turning the pump off.
If the eductor valve is not in the shutoff
position when turning the pump off, a si-
phoning action could be created, draining
the pump casing, the suction and dis-
charge lines, and the contaminated liquid
in the drum back into the tank.