Gorman-Rupp Pumps PA6C60C-F4L 1318119 thru 1504810 - Manual (Page 11)

OM-05768 PA SERIES
PAGE B - 4 INSTALLATION
should be the eccentric type, and should be in­
stalled with the flat part of the reducers uppermost
to avoid creating air pockets. Valves are not nor­
mally used in suction lines, but if a valve is used,
install it with the stem horizontal to avoid air pock­
ets.
Strainers
Be certain to use the strainer furnished with the
pump; any spherical solids which pass through the
strainer will also pass through the pump itself.
If a strainer not furnished with the pump is installed
by the pump user, make certain that the total area
of the openings in the strainer is at least three or
four times the cross section of the suction line, and
that the openings will not permit passage of solids
larger than the solids handling capability of the
pump.
This pump is designed to handle up to 3 inch (76,2
mm) diameter spherical solids.
Sealing
Since even a slight leak will affect priming, head,
and capacity, especially when operating with a
high suction lift, all connections in the suction line
should be sealed with pipe dope to ensure an air­
tight seal. Follow the sealant manufacturer's rec­
ommendations when selecting and applying the
pipe dope. The pipe dope should be compatible
with the liquid being pumped.
Suction Lines In Sumps
If a single suction line is installed in a sump, it
should be positioned away from the wall of the
sump at a distance equal to 1 1/2 times the diame­
ter of the suction line.
If there is a liquid flow from an open pipe into the
sump, the flow should be kept away from the suc­
tion inlet because the inflow will carry air down into
the sump, and air entering the suction line will re­
duce pump efficiency.
If it is necessary to position inflow close to the suc­
tion inlet, install a baffle between the inflow and the
suction inlet at a distance 1‐1/2 times the diameter
of the suction pipe. The baffle will allow entrained
air to escape from the liquid before it is drawn into
the suction inlet.
If two suction lines are installed in a single sump,
the flow paths may interact, reducing the efficiency
of one or both pumps. To avoid this, position the
suction inlets so that they are separated by a dis­
tance equal to at least 3 times the diameter of the
suction pipe.
Suction Line Positioning
The depth of submergence of the suction line is
critical to efficient pump operation. Figure 2
shows recommended minimum submergence vs.
velocity.
Although not recommended, the vacuum assisted
priming feature allows the pump to be operated
temporarily in a “slurping” application with varying
water levels.
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).