Gorman-Rupp Pumps VS6A60-B 1321070 thru 1352520 - Manual (Page 11)

OM-06014 ULTRA V SERIES
PAGE B - 4 INSTALLATION
Figure 1. 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 unless a si­
phon breaker is used in the line. Otherwise, a si­
phoning action causing damage to the pump
could result.
Valves
If the application involves a high discharge
head, the discharge throttling valve should
close gradually before the pump is
stopped.
Due to the high discharge head potential
for Ultra V Series pumps, an electronically
controlled or automatic slow‐closing dis­
charge throttling valve may be required.
Consult the factory for additional informa­
tion on high discharge head applications.
If a throttling valve is desired in the discharge line,
use a valve as large as the largest pipe to minimize
friction losses. Never install a throttling valve in a
suction line.
With high discharge heads, it is recommended that
a throttling valve and a system check valve be in­
stalled in the discharge line to protect the pump
from excessive shock pressure and reverse rota­
tion when it is stopped.
Bypass Lines
Self‐priming pumps are not air compressors. Dur­
ing the priming cycle, air from the suction line must
be vented to atmosphere on the discharge side. If
the discharge line is open, this air will be vented
through the discharge. However, if a check valve
has been installed in the discharge line, the dis­
charge side of the pump must be opened to atmos­
pheric pressure through a bypass line installed be­
tween the pump discharge and the check valve. A
self‐priming centrifugal pump will not prime if
there is sufficient static liquid head to hold the dis­
charge check valve closed.
NOTE
The bypass line should be sized so that it does not