Periodical Checks And Maintenance; Disassembly And Reassembly - Salvatore Robuschi RD-RDL-RDM Instructions Pour L'utilisation

make sure the maximum final pressure is not higher than the one
tolerated by the pump.
3. If the pump is supplied with a packing gland, check that the gland
exerts the right pressure against the seal rings. in case of
mechanicals seals, check that the cover is perfectly closed against
the casing. Open the washing liquid's feeding of the packing or of the
mechanical seal and regulate the flow.
4. If seal chamber's cooling is provided, open the feeding of the
cooling water, regulating its circulation.
5. When the pump is provided with steam preheating chambers, the
steam must flow in from the upper connections.
6. Start the pump with the delivery gate valve closed. Then open
slowly the discharge gate valve, regulating the working point within
the limits indicated on the plate. Make sure the rotation's direction is
the one shown by the arrow on the pump casing. If rotation is in the
opposite direction, reverse the connections of two phases.
Stopping the pump.
Close the delivery gate valve, if a check valve is not fitted.
Close the suction gate valve, if a check valve is not fitted
Switch off the motor.

5. PERIODICAL CHECKS AND MAINTENANCE

Caution: disconnect the electrical power before any
servicing operation.
Make sure the pump works in conformity with the range of specified
performance levels and the absorbed current indicated on the plate is
not exceeded.
Pumps with mechanical seal.
Mechanical seals do not require maintenance. Except for possible
initial leak after the first stat-up, the mechanical seal on the shaft
must function without any loss of liquid. Do not run the pump dry.
When a leak occurs and increases gradually, the seal must be
replaced.
Packing gland.
Pumps with packing glands need a little dripping.
When dripping through the stuffing box becomes excessive and it
cannot tighten any further, change the seal rings. (see fig. 5 and tab.
3).
Bearing.
Pumps are delivered without oil, therefore, before starting, it is
necessary to fill the bearing housing (see tab. 1).
About every 3000 working hours, remove ball bearing oil.
To choose oil viscosity follow tab. 1.
For grease lubrication follow tab. 2.
Liquid temp. Viscosity cSt
-10+50°C 22
10+70°C 32
70+120°C 68
Tab.1 Oil characteristics
Typ Grease Typ Grease
e [g] e
6305 5 -
6307 10 3307
6310 15 3310
Tab. 2 Grease characteristics

6. DISASSEMBLY AND REASSEMBLY

Before disassembling, close the suction and delivery gate valves.
See the sectional assembly drawing.
When working with dangerous
warnings.
7. SEALS REPLACEMENT
Packing gland
Use seal rings suitable for the liquid that should be pumped. Seal
rings have to be cut properly (fig. 5). It is necessary to alternate the
gasket slits, so that they don't fit each other.
d D
l
Fig.5 Packing gland
Suggested oil type
AGIP - OSSO, ESSO - TERESSO
IP - HYDRUS, SHELL - TELLUS
MOBIL - D.T.E.
N.L.G. Suggested grease
[g] I. type
- 3 ESSO – BEACON EP2
15 3 MOBIL – MOBILUX EP2
25 3 SHELL – ALVANIA EP
GREASER
liquids, follow the
L
Bearin Seal
g Diam.
d
25 33
35 43
50 53
Tab. 3: Packing gland's dimensions
Mechanical seals.
Stationary part mounting: make sure that the bevel (or chamfer) and
the housing are absolutely clean and free from ragged edges and
traces of working. Damp the housing and the stationary gasket with
alcohol, glycerine or a compatible liquid. Press the stationary part into
the housing using a covered stopper, mounted on the spindle of a
sensitive drill or a small press.
Rotary part mounting: make sure that shaft is smooth, clean and free
from sharp edges. Polish the shaft if necessary with a fine abrasive
cloth (about 400 grains) even if it has been ground. After having
damped the shaft with alcohol, glycerine etc, mount the rotary part
turning the seal with a gentle motion opposite to the spring's winding.
Make sure that the two lapped faces come into contact. It is harmful
to put grease, oil, and other similar substances between the seal's
faces, which must be absolutely clean (tab.3, tab.4).
8. REASSEMBLY
General principles
This operation is carried out by reversing the disassembly
instructions.
In particular remember to:
a) replace worn out bearings with others of the same type (see tab. 4)
b) replace coupling blocks with others of the same type
c) check clearances between wear rings and impeller's collar (tab. 5).
Size
32-12, 32,16, 32-20, 40-
12, 40-16, 40-20, 50-12,
50-16, 50-20
40-25, 50-25, 65-16, 65-
20, 65-25, 80-16, 80-20,
80-25, 100-20
65-31, 80-31, 80-40, 100-
25, 100-31, 100-40, 125-
25, 125-31, 125-40
Mounting clearances pump RD
Values indicated in the tab.5 are the lowest one for new pumps. After
a prolonged usage of the pump, these values could increase up to
50%.
Tolerances of these increases depend on the type of liquid pumped
and on the operational conditions, that is, delivery and suction
pressure. Very worn rings must be replaced.
b
due
Fig.6: RD pump section
Size
32-12, 32-16, 32-20
40-12, 40-16, 40-20
40-25, 50-12, 50-16, 50-
20
50-25, 65-16, 65-20, 65-
25
65-31, 80-16, 80-20, 80-
25
80-31, 80-40
100-20, 100-25, 100-31,
100-40
125-25,125-32, 125-40
Tab.5: Mounting clearance HD pumps
6
Chamber Packi Rings n°
dimension ng with
ring packing
ring
D l
55 65 10
68 78 12
78 80 12
Standard
bearings
Bearing
Lato Lato
gir. mot.
25 6305 6305
6307
35 3307
50 6310 3310
Tab. 4 Bearings
Fig.7 RG pump section
RD pumps
-0.1
D1 D2 D3 b
63.6 64 72 13
73.6 74 82 13
89.6 90 98 13
114.6 115 123 16
129.5 130 138 16
139.5 140 150 18
154.5 155 165 18
179.5 180 190 18
Rings n°
without
packing
ring
4 6
4 6
4 6
H.D. bearings
Lato
Lato gir.
mot.
3305
NJ 305
2*7305
3307
NJ307
2*7307
3310
NJ310
2*7310
s
Clearance
0.4-0.5
0.4-0.5
0.4-0.5
0.4-0.5
0.5-0.6
0.5-0.6
0.5-0.6
0.5-0.6