Pipe-Work; Connecting The Pipe-Work; Alignment Of Pump Motor Unit - Calpeda N Serie Instrucciones Originales De Uso

3. Pipe-work

The inside diameter of pipes depends on the deli-
very required.
The diameter should be determined so that the
liquid flow velocity will not exceed 1.5 m/sec in the
suction pipe and 3 m/sec in the delivery pipe. In
any case, pipe diameters must never be smaller
than the diameter of pump connection ports.
Minimum internal diameters (DN) of suction
pipes for different capacities (Q) are indicated in
the table below.
DN mm 50 65 80 100 125 150 200 250 300
Q max m 3 /h 10,5 19 28,8 45 75 108 215 350 508
The suction pipe must be perfectly air-tight and
lead upwards so as to avoid formation of air po-
ckets.
If a suction gate valve is mounted, the handwheel
must be positioned horizontally.
Use an eccentric transition piece to join the suction
connection with a horizontal pipe of larger diameter
(fig. 4).
b
c
d
Avoid formation of air pockets in suction
pipe:
a) eccentric transition piece;
b) gate valve with horizontal handwheel;
c) pipe leading upwards.
Avoid trasmission of stress to the pump:
d) supports and anchoring of pipes.
Fig. 4 Connection of pipes.
For suction operation, a foot valve with strainer
(constantly immersed) must be fitted.
For suction from a storage tank, a check valve
must be fitted.
For operation with positive suction head, a gate
valve must be fitted.
Follow local specifications if network pressure is to
be increased.
Fit a gate valve into the delivery pipe to adjust
delivery, head and absorbed power. Install a pres-
sure gauge.
When the geodetic head at delivery is above 15 m,
insert a check valve between the pump and gate
valve to protect the pump against water hamme-
ring.
10
a
4.93.040

3.1. Connecting the pipe-work

Do not use the pump to support pipes. Pipes
must be anchored on their own supports (fig. 4).
Pipes must be modified if they do not correspond
exactly with th eposition of connections to avoid
transmission of stress to the pump.
Position correctly any compensators (flexible expan-
sion joints) for absorption of expansion or vibration.
ATTENTION: forces and moments acting on
the pump flanges due to pipe loads may cause
misalignment of pump and driver shafts,
deformation and overstressing of pump ca-
sing, or overstressing of the fixing bolts
between pump and baseplate.
For connection of pipes to the flanged connection
ports, use standardized, circular counter-flanges
(type PN 10 or PN 16 up to DN 150).
During installation, make sure the gaskets between
flanges do not protrude inside pipes.
Make sure the inside of the pipe is clean before
connection.
In a new pipeline (especially when a suction strai-
ner is not fitted), insert a conical-type temporary
strainer on the suction side of the pump to prevent
solids (e.g. welding slags and scale) from entering
the pump. It is advisable to use a strainer with 20-
12,5 mesh (number of openings per linear inch)
and a free area at least three times greater than
the pipe inlet area (fig. 5).
Fig. 5 Conical-type temporary
strainer on the suction side.
4. Alignment of pump-motor unit
The pump-motor units positioned on a baseplate
and with a flexible coupling are aligned before lea-
ving the factory.
The pump and motor assembly can lose align-
ment during shipping. Final alignment must be
accomplished in the field.
After installation is completed with tigh-
tening of anchor bolts and connection of
pipes, alignment of the coupling must
be rechecked before starting the pump.
If necessary, the unit must be re-aligned.
4.1. Pump motor unit with N-EUPEX
coupling
Remove the coupling guard and with a dial indica-
tor or thickness gauge, make sure the distance (3-4
mm) between the halfcouplings is the same along
the entire periphery.
With a dial indicator or straight edge, check the alignment
(coaxiality) of the external part of the halfcouplings.
pump