REMKO RT 080, Руководство оператора, Страница: 9 / 40

8
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 airtight seal. Follow the sealant manufacturer's
recommendations 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 ½ times the diameter 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 suction inlet because the inflow will carry air down into the sump, and air
entering the suction line will reduce pump efficiency.
If it is necessary to position inflow close to the suction inlet, install a baffle between the
inflow and the in suction lines, it must be the rigid-wall, reinforced type to prevent
collapse under suction. Using piping couplings in suction lines is not recommended.
Suction inlet at a distance 1 ½ 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 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 distance 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 below 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).
VELOCITY (M./SEC.)= FLOW (M./MIN)x21.22 OR FLOW (M³/SEC.)
DIAMETER IN MM² AREA IN M²
Figure 2. Recommended Minimum Suction Line Submergence vs. Velocity
m
4.25
4.00
3.75
3.50
3.25
3.00
2.75
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
0.00
VELOCITY: Meters / Second
5.00
4.75
4.50
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 m/sec