GC Horizontal Multistage Boiler Feed Pump High Pressure

Product Overview 

The GC Horizontal Boiler Feed Multistage Centrifugal Pump is a new type of horizontal, single-suction, multistage centrifugal pump designed primarily for boiler feed applications. It is suitable for transporting clean water and other non-corrosive liquids with similar physical and chemical properties to water at temperatures up to 110°C.

This pump series is widely used in industrial and mining enterprises, public facilities, and municipal household water supply systems, particularly for boiler feed systems.

Model Designation

Key Features

• Multi-stage sectional design, allows for adjusting the head by adding or removing stages to meet different operational requirements.

• Precise alignment of the impeller and diffuser ensures stable flow, head, and efficiency.

• Balanced impellers during the manufacturing process minimize vibration.

• Axial thrust is balanced by a balancing disc and balancing ring assembly for stable operation.

• Cast iron sealing rings reduce internal leakage, improving efficiency.

• Durable shaft and bearing configuration ensure long service life.

• Simple structure, with clear wear parts for easy maintenance.

Engineering Summary 

The GC pump adopts a multi-stage sectional structure. For models from 1-1/2GC to 4GC, the inlet and discharge nozzles are arranged vertically upward on the suction sleeve and discharge casing, respectively. The pump head can be adjusted by adding or removing stages to meet varying operational conditions.

Pump performance is highly dependent on assembly precision, especially the alignment between each impeller outlet and the corresponding diffuser inlet. Precise concentric alignment is crucial, as even slight misalignment can reduce flow, head, and efficiency. Reassembly requires careful inspection and adjustment.

Typical Applications 

• Boiler feed systems

• Pressure vessel water supply

• Hot water circulation systems

• High-rise building water supply

• Agricultural irrigation

• Firefighting pressure enhancement

• Hydraulic washing systems

• Food processing, brewing, pharmaceutical, and chemical industries

• Aquaculture, environmental protection, chemical processing systems

• Mechanical support systems for water supply and drainage

System Configuration 

The GC system primarily consists of the following core components:

• Pump shaft and shaft sleeve

• Suction sleeve

• Driver

• Discharge diffuser

• Middle casing

• Discharge casing

• Sealing rings

• Balancing ring and balancing disc assembly

• End cover

• Bearings: Single-row deep groove ball bearings, lubricated with calcium-based grease

• Packing seal assembly: Includes stuffing box, gland, lantern ring, and packing

Components and Supply 

GC system components include:

• Pump body, bearing assembly

• Mechanical seal and shaft support system

• Electric motor and drive system

• Pipe fittings and installation accessories

Technical Service

The GC pump system provides comprehensive technical support and services, including installation and commissioning, operational monitoring, and maintenance recommendations. We provide detailed operation manuals, installation instructions, and remote technical support.

Operating Conditions 

• Pumped medium: Clean water or non-corrosive liquids with similar properties to water.

• Maximum liquid temperature: ≤110°C

• Ambient temperature: ≤40°C

• Bearing lubricants: Calcium-based grease

• Suitable for continuous operation in boiler feed and pressurization systems.

Service Conditions

• Fire hydrant system: Water gun flow rate of 2.5L/S, 5L/S, with jet lengths of 7m, 10m, and 13m.

• Automatic sprinkler system: Flow rate of 1.0L/S per nozzle, with a nozzle pressure of 0.1MPa.

• The environment temperature of the device: 5°C to 40°C.

Protection Functions 

The GC system is equipped with various protection functions, including overload protection, overpressure protection, and mechanical fault detection, ensuring safe and stable operation of the pump system under various extreme conditions.

Selection Criteria

The selection of the GC pump should be based on the specific application scenario, required flow rate, and head requirements. Consideration should also be given to installation space, ease of maintenance, and long-term system stability.

Installation & Dimensions

Outline Drawing

Performance Data

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 Diagram

Performance Data（2）

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

Outline Drawing（2）

Performance Data（2）

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

Pump Installation & Performance

Pump Head H Calculation:

Pump Head and Installation Calculations:

In the formula:

• P1: Suction pressure (MPa)

• P2: Discharge pressure (MPa)

• Z1: Vertical distance from the suction pressure gauge to the pump shaft center (m)

• Z2: Vertical distance from the discharge pressure gauge to the pump shaft center (m)

• V1: Flow velocity at the suction point (m/s)

• V2: Flow velocity at the discharge measuring point (m/s)

• ρ: Liquid density (kg/m³)

• g: Gravitational acceleration (9.8 m/s²)

Pump Installation Height (Mercury Alloy Calculation):
(Installation height refers to the vertical distance from the pump shaft centerline to the liquid level)
High point ≤ P0 – [NPSH] – P’ – △h – 0.5(m)

In the formula:

• P0: Atmospheric pressure (or absolute pressure at the liquid surface) (water column unit)

• [NPSH]: Net Positive Suction Head required by the pump (m)

• P’: Vapor pressure of the pumped liquid (m water column)

• △h: Hydraulic head loss (m)

Note:
When the pump shaft center is above the liquid level, the pump is positive (indicating suction mode).
When the value is negative, the pump is in submerged suction mode (indicating the pump is submerged in liquid).

The pump’s flow rate (Q), head (H), and shaft power (N) are related to the actual pump speed.

Calculation formula:

Operating Manual

Assembly and Disassembly

(I) Pump Disassembly Instructions

1. Follow the shutdown sequence to stop the pump.

2. Drain the liquid from the pump casing (including cooling water). If the bearings use oil lubrication, drain the oil as well.

3. Remove any auxiliary pipelines obstructing disassembly, such as balancing pipes, sealing water pipes, and electrical wires.

4. During disassembly, strictly protect the processing precision of all components. When removing the tie rod, use blocks to support the middle of the band tube to prevent the connecting joint from loosening or sinking, which could potentially bend the pump shaft.

(II) Pump Disassembly Sequence

1. Remove the bolts on the bearing end cover of the discharge side and the connecting bolts between the discharge casing, tail cover, and bearing casing. Remove the bearing end cover and bearing casing components.

2. Remove the circular nut on the shaft, then take out the inner bearing ring, bearing gland, and retaining ring. Disassemble the packing box assembly (including packing gland, lantern ring, and packing).

3. Remove the O-ring, shaft sleeve, balance disk, and key from the shaft. Then, remove the discharge sleeve, upper diffuser half, balance ring, and sleeve.

4. Remove the final impeller and key, then take out the middle casing and diffuser. Continue removing impellers, mid casings, and diffusers in stages until the first stage impeller is removed.

5. Remove the pump joint, then remove the connecting nuts between the suction casing and bearing casing and disassemble the bearing casing on the suction side.

6. Pull the shaft from the suction tube surface, remove the shaft nut, and take out the inner bearing ring, O-ring, shaft sleeve, etc.

7. For pumps with sleeve bearings, the operation method is similar, but the procedure for removing bearing components may differ slightly.

(III) Pump Assembly

Assembly is usually carried out in reverse order of disassembly. The quality of assembly directly affects the pump’s performance, service life, and reliability.

Key Points:

1. Protect the processing precision and surface smoothness of the components. Avoid scratches or dents. Molybdenum disulfide used for sealing must remain clean. All bolts and screws should be tightened to the correct torque.

2. Ensure proper axial dimensioning of each component to align the impeller outlet channel with the corresponding diffuser inlet channel. Misalignment can affect pump performance. The pump dimensions should not be altered at will.

3. After assembly and before installing packing, manually rotate the rotor to check if it rotates smoothly, and confirm that axial end movement is within tolerance.

4. After inspection, install the packing and ensure the lantern ring is correctly aligned in the packing chamber.

Preparation Work

(I) Startup Preparation

1. Rotate the pump rotor by hand before startup to ensure it rotates freely.

2. Confirm that the motor’s rotation direction matches the pump’s rotation direction.

3. Open the inlet valve, close the discharge valve, and the pressure gauge bracket to ensure the pump is fully primed, or use a vacuum system to evacuate air from the suction pipe and pump casing.

4. Check the tightness of the bolts connecting the pump and motor, and ensure the surrounding area is safe. The pump must be fully prepared for operation.

5. Power on the motor. After the pump reaches a stable speed, open the pressure gauge hole and gradually open the discharge valve until the pressure gauge indicates the desired discharge pressure (which corresponds to the required pump head).

(II) Operation

The pump series employs a balancing mechanism to offset axial thrust. Balanced water flows back into the suction pipe through a balancing pipe or via an external short pipe. The balancing water pipe must never be clogged.
2) During startup and operation, monitor instrument readings, bearing temperatures, packing leakage, pump vibration, and noise. Immediately address any abnormal conditions.
3) A rise in bearing temperature reflects assembly quality. The temperature increase in bearings should not exceed 35°C above ambient temperature. The maximum bearing temperature should not exceed 75°C.
4) The pump rotor will have a certain amount of axial float during operation. The axial shift must remain within the allowable range. Maintain proper clearance between the motor and pump coupling.
5) Periodically check components such as the impeller, wear rings, lantern rings, shaft sleeves, and balance discs for wear. Replace parts when significant wear occurs.

(III) Shutdown

1. Before stopping, close the discharge valve gradually, and then cut off the power supply to the motor. After the pump has completely stopped, close the inlet valve.

2. Drain the liquid from the pump. For long-term shutdown, disassemble, clean, lubricate, and properly store the pump.

OEM & Custom

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

1. 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.
2. Q: What is the maximum temperature the pump can handle?
   A: Up to 110°C for clean or slightly hot water applications.
3. Q: What materials are available?
   A: Standard cast iron; optional stainless steel or alloy for specific industrial fluids.
4. 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.
5. Q: What kind of seal is used?
   A: Standard packing seal; mechanical seals available for optional configurations.
6. Q: How should the pump be maintained?
   A: Regular lubrication, seal inspection, and yearly performance checks are recommended.
7. Q: Which industries use GC pumps?
   A: Power plants, manufacturing, chemical processing, HVAC, and water supply projects globally.