Mas Grup
5
Install the coupling guard only when the alignment of the coupling is
checked.
Wrong
Right
X2>X1>X
X2=X1=X
Wrong
Right
Figure 4:
The Control of the Coupling Alignment in Horizontal and
Vertical Planes
6.4.3. Belt Alignment for Groups Connected with V-Belts
V-belt alignment:
A proper belting alignment increases the life of the system.
Make sure that the pump and motor shafts are connected to each other.
V-belt tension alignment:
V-belts must be placed properly inside pulley grooves.
1. The tension alignment of belts is made by moving the pulley centers
until the correct belt tension is obtained.
2. Belt tension is checked by pushing on it by hand. A belt with normal
tension may deflect 1/20 of the distance between the axes. If it deflects
more than this amount, the belt is considered loose, otherwise it is too
tight.
3. During operation; in a couple of days, the belts are going to be fully
placed inside pulley grooves. It may be necessary to align the belt while
it is slightly curved on one side.
Figure 5:
Belt Tension Check
4. Properly tightened belting becomes ready for operation with regular
checks of belt tension.
Figure 6:
Misaligned and Aligned Belts
6.4.4. Pump and Motor Mounting (Coupling)
If the coupling of the pump group is to be mounted on site,
the following procedure should be followed
1. Insert the key.
2. Push the coupling halves with a driving apparatus towards the pump
and the motor shafts, until the shaft is fit to snag to the hub of the
coupling. If a driving apparatus is not available, heating coupling halves
(with coupling rubbers
off) to an approximately 100 °C may help the
pushing. It is important that axial force is prevented from occurring while
mounting the coupling. Support pump shaft from the impeller side, and
motor shaft from the fan side while mounting the coupling. If necessary,
dismantle the fan cover.
3. Screw the two bolts in coupling hub.
4. Make sure that a suitable spacing is left between the coupling halves
while mounting pump and the rotor.
5. Horizontal pump groups mounted on the base plate or directly mounted
on the base, alignment of the coupling shall be as described in 6.4.2
6. Put into place the coupling guard.
According to the accident prevention regulations, all preventions
and protective devices should be in their intended place and in
operational form.
6.5. Piping
6.5.1. Suction snd Discharge Piping
Pump performance is adversely affected by increase suction lift,
discharge elevation and friction losses. See the performance curve and
operating range to be sure your overall application allows pump to
operate within the safe operation range.
6.5.1.1. Material
Either pipe or hose may be used for suction and discharge lines.
However, the materials must be compatible with liquid being pumped. If
hose is used in suction line, it must be the rigid-wall, reinforced type to
prevent collapse under suction.
6.5.1.2. Line Configuration
Keep suction and discharge lines as straight as possible to minimize
friction losses. Make minimum use of elbows and fittings, which
substantially increase friction losses. If elbows are necessary, use the
long radius type to minimize friction losses.
6.5.1.3. Connections of Pump
Before tightening a connection flange, align it exactly with the pump port.
Never pull a pipe line into place by tightening the flange bolts and/or
couplings.
Lines near the pump must be independently supported to avoid strain on
the pump which could cause excessive vibration, decrease bearing life
and increase shaft and seal wear. If hose-type lines are used, they should
have adequate support to secure them when filled with liquid and under
pressure.
6.5.1.4. Gauges
Most pumps are drilled and tapped for installing discharge pressure and
vacuum suction gauges. If these gauges are desired for pumps that are
not tapped, drill and tape the suction and discharge lines not less than
18” (457.2 mm) from the suction and discharge ports and install the lines.
Installation closer to the pump may result in erratic reading.