Product Description
Model Code Explanation
Product Introduction
The GC horizontal boiler feed multistage clean water pump is a horizontal single-suction multistage sectional centrifugal pump, mainly used for boiler feed water, and is therefore also known as a horizontal boiler feed multistage pump. This series is suitable for conveying clean water or other non-corrosive liquids with physical and chemical properties similar to water, with temperatures below 110°C. It is widely used for boiler water supply in industrial and mining enterprises, public institutions, and municipal domestic water systems.
Product Features
The GC horizontal boiler feed multistage clean water pump is of a multistage sectional design. For the four models 1-1/2GC to 4GC, the inlet and outlet are located on the suction casing and the discharge casing respectively, both vertically upward. The pump head can be increased or decreased by adjusting the number of stages according to usage requirements.
The assembly quality of the pump greatly affects its performance, especially the alignment between the impeller outlet and the diffuser inlet. The outlet center of each impeller must be precisely aligned with the center of the diffuser. Even slight misalignment may reduce pump flow, decrease head, and lower efficiency. Therefore, special attention is required during reassembly after maintenance, and any deviation must be corrected.
Main components of the GC pump include: shaft, shaft sleeve, suction casing, impeller, diffuser, seal ring, middle casing, discharge casing, balance ring, balance disc, and tail cover.
• The suction casing, middle casing, discharge casing, and tail cover are all made of cast iron and jointly form the pump chamber.
• The impeller is made of cast iron with internal blades. Liquid enters axially from one side. Due to pressure differences at the front and rear of the impeller, axial thrust exists, which is absorbed by the balance disc. Each impeller undergoes static balance testing during manufacturing.
• The shaft is made of high-quality carbon steel. The impellers are mounted on the shaft using keys, shaft sleeves, and shaft sleeve nuts. One end of the shaft is fitted with a coupling to connect directly to the motor. Viewed from the drive end, the pump rotates clockwise.
• The seal ring, made of cast iron, prevents high-pressure water inside the pump from leaking back into the suction section. It is fixed on the suction casing and middle casing. As a wear part, it should be replaced when worn.
• The balance ring, made of cast iron, is fixed on the discharge casing and forms a balancing assembly with the balance disc.
• The balance disc, made of wear-resistant cast iron, is installed on the shaft between the discharge casing and the tail cover to balance axial thrust.
• The shaft sleeve, made of cast iron, is located at the stuffing box on both sides, used for fixing the impeller and protecting the pump shaft; it is a wear part and should be replaced when worn.
• The bearings are single-row deep groove ball bearings, lubricated with calcium-based grease.
• The stuffing seal consists of stuffing boxes on the suction casing and tail cover, gland, lantern ring, and packing. A small amount of high-pressure water enters the stuffing box to provide sealing. The packing must be properly tightened—not too tight nor too loose. It should allow the liquid to drip out one drop at a time. If too tight, the shaft sleeve may overheat and additional power will be consumed. If too loose, leakage will reduce pump efficiency.
Product Applications
The GC horizontal boiler feed multistage clean water pump can also be widely used in pressure vessel water supply, hot-water circulation, high-rise building water supply, farmland irrigation, fire-fighting pressurization, hydraulic flushing, food processing, brewing, pharmaceuticals, chemical industry, aquaculture, environmental protection, chemical process systems, and machinery supporting systems as a power device for water supply and drainage.
Structural Diagram
|
1
|
Shaft Sleeve Nut
|
2
|
Bearing Cover
|
3
|
Bearing
|
4
|
Front Bearing Housing
|
5
|
Shaft Sleeve (A)
|
6
|
Packing Gland
|
7
|
Lantern Ring
|
|
8
|
Wear Ring
|
9
|
Suction Casing
|
10
|
Impeller
|
11
|
Middle Casing
|
12
|
Return Pipe
|
13
|
Discharge Casing
|
14
|
Balance Ring
|
|
15
|
Balance Disc
|
16
|
Tail Cover
|
17
|
Shaft Sleeve (B)
|
18
|
Shaft
|
19
|
Round Nut
|
20
|
Tension Bolt
|
Performance Parameters
|
Model
|
Stages
|
Flow Rate Q
|
Total Head H
|
Speed n
|
Power N (kW)
|
Efficiency η
|
NPSH
|
Impeller Diameter
|
Weight
|
||
|
m3/h
|
L/S
|
m
|
r/min
|
Shaft Power
|
Motor Power (kW)
|
%
|
m
|
mm
|
Kg
|
||
|
11/2GC-5
|
2
|
6
|
1.66
|
46
|
2950
|
2
|
3
|
38
|
3.7
|
136
|
135
|
|
11/2GC-5
|
3
|
6
|
1.66
|
69
|
2920
|
3
|
4
|
38
|
3.7
|
136
|
147
|
|
11/2GC-5
|
4
|
6
|
1.66
|
92
|
2920
|
4
|
5.5
|
38
|
3.7
|
136
|
174
|
|
11/2GC-5
|
5
|
6
|
1.66
|
115
|
2920
|
5
|
7.5
|
38
|
3.7
|
136
|
204
|
|
11/2GC-5
|
6
|
6
|
1.66
|
138
|
2920
|
6
|
7.5
|
38
|
3.7
|
136
|
212
|
|
11/2GC-5
|
7
|
6
|
1.66
|
161
|
2920
|
7
|
7.5
|
38
|
3.7
|
136
|
220
|
|
11/2GC-5
|
8
|
6
|
1.66
|
184
|
2920
|
8
|
11
|
38
|
3.7
|
136
|
271
|
|
11/2GC-5
|
9
|
6
|
1.66
|
207
|
2920
|
9
|
15
|
38
|
3.7
|
136
|
292
|
|
Model
|
Stages
|
Flow Rate Q
|
Total Head H
|
Speed n
|
Power N (kW)
|
Efficiency η
|
NPSH
|
Impeller Diameter
|
Weight
|
||
|
m3/h
|
L/S
|
m
|
r/min
|
Shaft Power
|
Motor Power (kW)
|
%
|
m
|
mm
|
Kg
|
||
|
2GC-5
|
2
|
10
|
2.8
|
64
|
2950
|
4.4
|
7.5
|
39.6
|
4.7
|
166
|
258
|
|
2GC-5
|
3
|
10
|
2.8
|
96
|
2950
|
6.6
|
11
|
39.6
|
4.7
|
166
|
309
|
|
2GC-5
|
4
|
10
|
2.8
|
128
|
2950
|
8.8
|
15
|
39.6
|
4.7
|
166
|
389
|
|
2GC-5
|
5
|
10
|
2.8
|
160
|
2950
|
11.0
|
15
|
39.6
|
4.7
|
166
|
414
|
|
2GC-5
|
6
|
10
|
2.8
|
192
|
2950
|
13.2
|
18.5
|
39.6
|
4.7
|
166
|
512
|
|
2GC-5
|
7
|
10
|
2.8
|
224
|
2950
|
15.4
|
22.0
|
39.6
|
4.7
|
166
|
531
|
|
2GC-5
|
8
|
10
|
2.8
|
256
|
2950
|
17.6
|
30.0
|
39.6
|
4.7
|
166
|
589
|
|
2GC-5
|
9
|
10
|
2.8
|
288
|
2950
|
19.8
|
30.0
|
39.6
|
4.7
|
166
|
609
|
|
Model
|
Stages
|
Flow Rate Q
|
Total Head H
|
Speed n
|
Power N (kW)
|
Efficiency η
|
NPSH
|
Impeller Diameter
|
Weight
|
||
|
m3/h
|
L/S
|
m
|
r/min
|
Shaft Power
|
Motor Power (kW)
|
%
|
m
|
mm
|
Kg
|
||
|
21/2GC-3.5
|
7
|
10
15 20 |
2.8
4.2 5.6 |
336
315 280 |
2950
|
26
28.6 32.5 |
37
|
35
45 47 |
3.3
3.8 4 |
198
|
967
|
|
21/2GC-3.5
|
8
|
10
15 20 |
2.8
4.2 5.6 |
384
360 320 |
2950
|
30
32.8 37 |
45
|
35
45 47 |
3.3
3.8 4 |
198
|
1065
|
|
21/2GC-3.5
|
9
|
10
15 20 |
2.8
4.2 5.6 |
432
405 360 |
2950
|
33.7
37 42 |
55
|
35
45 47 |
3.3
3.8 4 |
198
|
1097
|
|
21/2GC-3.5
|
10
|
10
15 20 |
2.8
4.2 5.6 |
480
450 400 |
2950
|
37.5
41 46.5 |
55
|
35
45 47 |
3.3
3.8 4 |
198
|
1179
|
|
21/2GC-3.5
|
11
|
10
15 20 |
2.8
4.2 5.6 |
528
495 440 |
2950
|
41.5
45 51 |
75
|
35
45 47 |
3.3
3.8 4 |
198
|
1252
|
|
21/2GC-3.5
|
12
|
10
15 20 |
2.8
4.2 5.6 |
576
540 480 |
2950
|
45
49 56 |
75
|
35
45 47 |
3.3
3.8 4 |
198
|
1324
|
|
Model
|
Stages
|
Flow Rate Q
|
Total Head H
|
Speed n
|
Power N (kW)
|
Efficiency η
|
NPSH
|
Impeller Diameter
|
Weight
|
||
|
m3/h
|
L/S
|
m
|
r/min
|
Shaft Power
|
Motor Power (kW)
|
%
|
m
|
mm
|
Kg
|
||
|
21/2GC-6
|
2
|
15
20 |
4.2
5.6 |
62
54 |
2950
|
5.8
6.2 |
7.5
|
43.7
47.4 |
5
5.3 |
168
|
258
|
|
21/2GC-6
|
3
|
15
20 |
4.2
5.6 |
93
81 |
2950
|
8.7
9.3 |
15
|
43.7
47.4 |
5
5.3 |
168
|
309
|
|
21/2GC-6
|
4
|
15
20 |
4.2
5.6 |
124
108 |
2950
|
11.6
12.4 |
18.5
|
43.7
47.4 |
5
5.3 |
168
|
389
|
|
21/2GC-6
|
5
|
15
20 |
4.2
5.6 |
155
135 |
2950
|
14.5
15.5 |
22.0
|
43.7
47.4 |
5
5.3 |
168
|
494
|
|
21/2GC-6
|
6
|
15
20 |
4.2
5.6 |
186
162 |
2950
|
17.4
18.6 |
22.0
|
43.7
47.4 |
5
5.3 |
168
|
512
|
|
21/2GC-6
|
7
|
15
20 |
4.2
5.6 |
217
189 |
2950
|
20.2
21.7 |
30.0
|
43.7
47.4 |
5
5.3 |
168
|
563
|
|
21/2GC-6
|
8
|
15
20 |
4.2
5.6 |
248
216 |
2950
|
23.2
24.8 |
30.0
|
43.7
47.4 |
5
5.3 |
168
|
589
|
|
21/2GC-6
|
9
|
15
20 |
4.2
5.6 |
279
243 |
2950
|
26.1
27.9 |
37.0
|
43.7
47.4 |
5
5.3 |
168
|
785
|
|
Model
|
Stages
|
Flow Rate Q
|
Total Head H
|
Speed n
|
Power N (kW)
|
Efficiency η
|
NPSH
|
Impeller Diameter
|
Weight
|
||
|
m3/h
|
L/S
|
m
|
r/min
|
Shaft Power
|
Motor Power (kW)
|
%
|
m
|
mm
|
Kg
|
||
|
4GC-8
|
2
|
30
45 55 |
8.3
12.5 15.3 |
86
82 79 |
2950
|
13.8
16.8 18.1 |
22
|
51
60 62.5 |
4.6
5 5.6 |
192
|
503
|
|
4GC-8
|
3
|
30
45 55 |
8.3
12.5 15.3 |
129
123 114 |
2950
|
20.7
25.2 27.2 |
30
|
51
60 62.5 |
4.6
5 5.6 |
192
|
612
|
|
4GC-8
|
4
|
30
45 55 |
8.3
12.5 15.3 |
172
164 152 |
2950
|
27.6
33.6 35.2 |
45
|
51
60 62.5 |
4.6
5 5.6 |
192
|
835
|
|
4GC-8
|
5
|
30
45 55 |
8.3
12.5 15.3 |
215
205 190 |
2950
|
34.5
42 45.3 |
55
|
51
60 62.5 |
4.6
5 5.6 |
192
|
950
|
|
4GC-8
|
6
|
30
45 55 |
8.3
12.5 15.3 |
258
246 228 |
2950
|
41.4
50.4 54.4 |
55
|
51
60 62.5 |
4.6
5 5.6 |
192
|
1085
|
|
4GC-8
|
7
|
30
45 55 |
8.3
12.5 15.3 |
301
287 266 |
2950
|
48.3
58.8 63.4 |
75
|
51
60 62.5 |
4.6
5 5.6 |
192
|
1087
|
|
4GC-8
|
8
|
30
45 55 |
8.3
12.5 15.3 |
344
328 304 |
2950
|
55
67 73 |
75
|
51
60 62.5 |
4.6
5 5.6 |
192
|
|
|
4GC-8
|
9
|
30
45 55 |
8.3
12.5 15.3 |
387
369 342 |
2950
|
62
75.5 82 |
90
|
51
60 62.5 |
4.6
5 5.6 |
192
|
|
|
4GC-8
|
10
|
30
45 55 |
8.3
12.5 15.3 |
430
410 380 |
2950
|
69
84 91 |
100
|
51
60 62.5 |
4.6
5 5.6 |
192
|
|
Installation Dimensions
|
Model
|
Number of Stages
|
A
|
B
|
C
|
E
|
H
|
I
|
J
|
K
|
L
|
M
|
N
|
O
|
P
|
Q
|
F
|
n-φd
|
|
11/2GC-5
|
2
|
963
|
750
|
510
|
128
|
248
|
122.5
|
355
|
350
|
205
|
365
|
105
|
180
|
315
|
315
|
154
|
4-φ20
|
|
11/2GC-5
|
3
|
1033
|
805
|
535
|
125
|
248
|
172.5
|
355
|
358
|
205
|
405
|
115
|
190
|
355
|
355
|
154
|
4-φ20
|
|
11/2GC-5
|
4
|
1158
|
1010
|
715
|
135
|
248
|
222.5
|
360
|
393
|
205
|
415
|
135
|
210
|
365
|
365
|
47
|
4-φ20
|
|
11/2GC-5
|
5
|
1208
|
1010
|
715
|
135
|
248
|
272.5
|
360
|
393
|
205
|
415
|
135
|
210
|
365
|
365
|
97
|
4-φ20
|
|
11/2GC-5
|
6
|
1258
|
1010
|
715
|
135
|
248
|
322.5
|
360
|
393
|
205
|
415
|
135
|
210
|
365
|
365
|
147
|
4-φ20
|
|
11/2GC-5
|
7
|
1308
1433 |
1060
1180 |
715
760 |
135
170 |
248
|
372.5
|
360
|
393
495 |
205
|
415
470 |
135
163 |
210
255 |
365
|
365
240 |
147
100 |
4-φ20
|
|
11/2GC-5
|
8
|
1484
|
1280
|
785
|
170
|
248
|
422.5
|
395
|
470
|
205
|
470
|
165
|
255
|
365
|
420
|
95
|
4-φ20
|
|
11/2GC-5
|
9
|
1533
|
1280
|
785
|
170
|
248
|
472.5
|
395
|
470
|
205
|
470
|
165
|
255
|
365
|
420
|
145
|
4-φ20
|
|
Model
|
Number of Stages
|
A
|
B
|
C
|
E
|
H
|
I
|
J
|
K
|
L
|
M
|
N
|
O
|
P
|
Q
|
F
|
n-φd
|
|
2GC-5
|
2
|
1227
|
915
|
650
|
135
|
325
|
160
|
480
|
443
|
255
|
490
|
135
|
210
|
430
|
430
|
211
|
4-φ24
|
|
2GC-5
|
3
|
1412
|
1160
|
790
|
165
|
325
|
220
|
485
|
490
|
255
|
480
|
165
|
255
|
430
|
430
|
141
|
4-φ24
|
|
2GC-5
|
4
|
1412
|
1160
|
790
|
165
|
325
|
280
|
485
|
490
|
255
|
480
|
165
|
255
|
430
|
430
|
201
|
4-φ24
|
|
2GC-5
|
5
|
1532
|
1220
|
820
|
165
|
325
|
340
|
485
|
490
|
255
|
480
|
165
|
255
|
430
|
430
|
201
|
4-φ24
|
|
2GC-5
|
6
|
1637
|
1320
|
860
|
185
|
325
|
400
|
485
|
490
|
255
|
480
|
165
|
255
|
430
|
430
|
203
|
4-φ24
|
|
2GC-5
|
7
|
1722
|
1380
|
900
|
200
|
325
|
460
|
480
|
510
|
255
|
515
|
180
|
285
|
455
|
455
|
209
|
4-φ24
|
|
2GC-5
|
8
|
1887
|
1575
|
1000
|
240
|
325
|
520
|
525
|
580
|
255
|
585
|
200
|
310
|
440
|
525
|
150
|
4-φ24
|
|
2GC-5
|
9
|
1947
|
1575
|
1000
|
240
|
325
|
580
|
525
|
580
|
255
|
585
|
200
|
310
|
440
|
525
|
210
|
4-φ24
|
|
Model
|
Number of Stages
|
A
|
B
|
C
|
E
|
H
|
I
|
J
|
K
|
L
|
M
|
N
|
O
|
P
|
Q
|
F
|
n-φd
|
|
21/2GC-3.5
|
7
|
1937
|
1590
|
1030
|
225
|
385
|
470
|
608
|
598
|
295
|
600
|
200
|
310
|
540
|
540
|
195
|
4-φ24
|
|
21/2GC-3.5
|
8
|
1937
|
1675
|
1085
|
225
|
385
|
530
|
618
|
638
|
295
|
600
|
225
|
345
|
540
|
540
|
194
|
4-φ24
|
|
21/2GC-3.5
|
9
|
2212
|
1835
|
1170
|
265
|
385
|
590
|
643
|
683
|
295
|
600
|
250
|
385
|
540
|
610
|
192
|
4-φ24
|
|
21/2GC-3.5
|
10
|
2272
|
1895
|
1200
|
265
|
385
|
650
|
643
|
683
|
295
|
600
|
250
|
385
|
540
|
610
|
192
|
4-φ24
|
|
21/2GC-3.5
|
11
|
2402
|
2115
|
1280
|
320
|
385
|
710
|
675
|
750
|
295
|
715
|
280
|
410
|
530
|
655
|
131
|
4-φ24
|
|
21/2GC-3.5
|
12
|
2462
|
2115
|
1280
|
320
|
385
|
770
|
675
|
750
|
295
|
715
|
280
|
410
|
530
|
655
|
191
|
4-φ24
|
|
型号
|
Number of Stages
|
A
|
B
|
C
|
E
|
H
|
I
|
J
|
K
|
L
|
M
|
N
|
O
|
P
|
Q
|
F
|
n-φd
|
|
21/2GC-6
|
2
|
1227
|
915
|
650
|
135
|
325
|
160
|
480
|
443
|
255
|
490
|
135
|
210
|
430
|
430
|
211
|
4-φ24
|
|
21/2GC-6
|
3
|
1412
|
1160
|
790
|
165
|
325
|
220
|
485
|
490
|
255
|
480
|
165
|
255
|
430
|
430
|
141
|
4-φ24
|
|
21/2GC-6
|
4
|
1412
|
1160
|
790
|
165
|
325
|
280
|
485
|
490
|
255
|
480
|
165
|
255
|
430
|
430
|
201
|
4-φ24
|
|
21/2GC-6
|
5
|
1577
|
1320
|
860
|
185
|
325
|
340
|
485
|
490
|
255
|
480
|
165
|
255
|
430
|
430
|
143
|
4-φ24
|
|
21/2GC-6
|
6
|
1662
|
1380
|
900
|
200
|
325
|
400
|
480
|
510
|
255
|
515
|
180
|
285
|
455
|
455
|
149
|
4-φ24
|
|
21/2GC-6
|
7
|
1827
|
1575
|
1000
|
240
|
325
|
460
|
525
|
580
|
255
|
585
|
200
|
310
|
440
|
525
|
90
|
4-φ24
|
|
21/2GC-6
|
8
|
1887
|
1575
|
1000
|
240
|
325
|
520
|
525
|
580
|
255
|
585
|
200
|
310
|
440
|
525
|
150
|
4-φ24
|
|
21/2GC-6
|
9
|
1947
|
1575
|
1000
|
240
|
325
|
525
|
525
|
580
|
255
|
585
|
200
|
310
|
440
|
525
|
210
|
4-φ24
|
|
Model
|
Number of Stages
|
A
|
B
|
C
|
E
|
H
|
I
|
J
|
K
|
L
|
M
|
N
|
O
|
P
|
Q
|
F
|
n-φd
|
|
4GC-8
|
2
|
1552
|
1230
|
845
|
190
|
385
|
190
|
610
|
575
|
295
|
600
|
180
|
285
|
540
|
480
|
185
|
4-φ24
|
|
4GC-8
|
3
|
1732
|
1385
|
925
|
225
|
385
|
265
|
610
|
600
|
295
|
600
|
200
|
310
|
540
|
540
|
185
|
4-φ24
|
|
4GC-8
|
4
|
1847
|
1485
|
980
|
235
|
385
|
340
|
620
|
640
|
295
|
600
|
225
|
345
|
540
|
540
|
184
|
4-φ24
|
|
4GC-8
|
5
|
2037
|
1735
|
1105
|
265
|
385
|
415
|
645
|
685
|
295
|
665
|
250
|
385
|
540
|
605
|
117.5
|
4-φ24
|
|
4GC-8
|
6
|
2112
|
1735
|
1105
|
265
|
385
|
490
|
645
|
685
|
295
|
665
|
250
|
385
|
540
|
605
|
192.5
|
4-φ24
|
|
4GC-8
|
7
|
2257
|
1955
|
1215
|
300
|
385
|
565
|
675
|
750
|
295
|
720
|
280
|
410
|
540
|
660
|
116.5
|
4-φ24
|
|
4GC-8
|
8
|
2332
|
1955
|
1215
|
300
|
385
|
640
|
675
|
750
|
295
|
720
|
280
|
410
|
540
|
660
|
191.5
|
4-φ24
|
|
4GC-8
|
9
|
2457
|
2080
|
1295
|
325
|
385
|
715
|
675
|
750
|
295
|
720
|
280
|
410
|
540
|
660
|
191.5
|
4-φ24
|
Suction & Discharge Flanges
|
Dimension
|
Suction Flange
|
|||
|
Model
|
Dg
|
Do
|
D
|
n–do
|
|
11/2GC-5
|
40
|
115
|
145
|
4-φ18
|
|
2GC-5
|
50
|
125
|
160
|
4-φ18
|
|
21/2GC-6
|
65
|
145
|
180
|
8-φ18
|
Simple Calculation Description
Pump Head H Calculation:
In the formula:
P1: Inlet pressure (MPa)
P2: Outlet pressure (MPa)
Z1: Vertical distance from inlet pressure gauge to pump shaft center (m)
Z2: Vertical distance from outlet pressure gauge to pump shaft center (m)
V1: Flow velocity at inlet measuring point (m/s)
V2: Flow velocity at outlet measuring point (m/s)
ρ: Liquid density (kg/m³)
g: Gravitational acceleration (9.8 m/s²)
Pump Installation Height Hg Calculation:
(Installation height refers to the vertical distance from pump shaft centerline to liquid level)
Hg ≤ P₀ – [NPSH] – P’ – △h – 0.5 (m)
In the formula:
P₀: Atmospheric pressure (or absolute pressure at liquid surface) (m of water column)
[NPSH]: Net Positive Suction Head required by the pump (m)
P’: Vapor pressure of the pumped liquid (m of water column)
△h: Hydraulic loss of the suction pipeline (m)
Note: When Hg is positive, the pump shaft center is above liquid level; when negative, the pump is under flooded suction (submerged).
The pump flow rate (Q), head (H), and shaft power (N) are related to the actual pump speed.
Calculation formula:
Assembly & Disassembly
(I) Notes for Pump Disassembly
1) Stop the pump according to the shutdown sequence.
2) Drain liquid from the pump casing (including cooling water). If the bearing uses oil lubrication, drain the lubricating oil as well.
3) Remove auxiliary pipelines that obstruct disassembly, such as balance pipes, seal-water pipes, and electrical wiring.
4) During disassembly, strictly protect the machining accuracy of all components. When removing tie rods, support the middle casings with blocks to prevent the rabbet joints from loosening or sinking, which may bend the pump shaft.
(II) Pump Disassembly Sequence
1) Remove bolts on the discharge-side bearing end cover and the connection bolts among the discharge casing, tail cover, and bearing housing. Remove the bearing end cover and bearing housing components.
2) Remove the round nut on the shaft, then remove the inner bearing ring, bearing gland, and retaining ring. Remove the stuffing box components (packing gland, lantern ring, packing, etc.).
3) Remove the O-ring, shaft sleeve, balance disc, and key from the shaft; then remove the discharge casing, last-stage diffuser, balance ring, and sleeve.
4) Remove the last-stage impeller and key, then remove the middle casing and diffuser. Continue removing impellers, middle casings, and diffusers stage-by-stage until the first-stage impeller is removed.
5) Remove the pump coupling, then remove the connection nuts between the suction casing and bearing housing, and remove the bearing housing on the suction side.
6) Pull the shaft out from the suction casing, remove the shaft nut, and remove the inner bearing ring, O-ring, shaft sleeve, etc.
7) For pumps using sleeve bearings, the procedure is similar but differs slightly when removing bearing components.
(III) Pump Assembly
Assembly is generally performed in the reverse order of disassembly. Assembly quality directly affects pump performance, service life, and reliability.
Key points:
1) Protect machining accuracy and surface finish of components. Avoid scratches or dents. Molybdenum disulfide used for sealing must be kept clean. Tighten bolts and screws evenly.
2) Alignment between impeller outlet channels and diffuser inlet channels must be ensured by proper axial dimensions of each component. Misalignment affects pump performance—pump dimensions must not be adjusted arbitrarily.
3) After assembly and before installing packing, rotate the rotor by hand to check smooth rotation and verify axial end-play is within tolerance.
4) After inspection, install packing and ensure proper alignment of the lantern ring within the stuffing chamber.
Preparations
(I) Start-Up
1) Rotate the pump rotor by hand before start-up to ensure it rotates freely.
2) Confirm the motor rotation direction matches the pump rotation direction.
3) Open the inlet valve, close the discharge valve and pressure gauge cock, ensure the pump is fully primed or use a vacuum system to remove air from the suction line and pump casing.
4) Check tightness of bolts connecting pump and motor, and ensure surrounding area is safe. The pump must be in a fully ready state.
5) Start the motor. After the pump runs smoothly, open the pressure gauge cock, and slowly open the discharge valve until the pressure gauge indicates the required discharge pressure (which corresponds to the required pump head).
(II) Operation
1) This pump series uses a balance mechanism to counteract axial thrust. Balance water flows through the balance pipe back to the suction casing or through an external short pipe. The balance water pipe must NEVER be blocked.
2) During startup and operation, monitor gauge readings, bearing temperature, packing leakage, pump vibration, and noise. Correct any abnormalities immediately.
3) Bearing temperature rise reflects assembly quality. Bearing temperature rise must not exceed 35°C above ambient temperature; maximum bearing temperature must not exceed 75°C.
4) The pump rotor has a certain axial float during operation. Axial movement must remain within allowable limits. Maintain proper clearance between motor and pump couplings.
5) Regularly inspect impellers, wear rings, diffusers, shaft sleeves, balance discs, and other wear parts. Replace them when severely worn.
(III) Shutdown
1) Before shutdown, first close the pressure gauge cock, then slowly close the discharge valve. After the valve is fully closed, turn off the motor. Once the pump stops completely, close the inlet valve.
2) Drain water from the pump. For long-term shutdown, disassemble, clean, lubricate, and store the pump properly.
OEM & Custom Solutions
We provide OEM/ODM manufacturing with customizable materials (cast iron, stainless steel, alloy steel), voltages (220V/415V/460V), and control systems. Options include explosion-proof motors, extended shafts, and flange customization (DIN/ANSI/JIS). Each pump is hydraulically tested to meet ISO9001 and CE standards for global markets.
FAQs for Oversea Buyers
Q: What is the main application of GC multistage pumps?
A: Mainly used for boiler feed, pressure boosting, and clean water supply in industrial and municipal systems.
Q: What is the maximum temperature the pump can handle?
A: Up to 110°C for clean or slightly hot water applications.
Q: What materials are available?
A: Standard cast iron; optional stainless steel or alloy for specific industrial fluids.
Q: What is the maximum head and flow range?
A: Head up to 400 meters; flow rate 6–55 m³/h depending on model and stage number.
Q: What kind of seal is used?
A: Standard packing seal; mechanical seals available for optional configurations.
Q: How should the pump be maintained?
A: Regular lubrication, seal inspection, and yearly performance checks are recommended.
Q: Which industries use GC pumps?
A: Power plants, manufacturing, chemical processing, HVAC, and water supply projects globally.