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Having 26 series -312 varieties - over 1000 pump models
Focused on water pump research and development manufacturing for 36 years
Free training for operation and maintenance personnel/free installation guidance/free provision of installation drawings
DG-type multistage boiler feed pump
Flow rate: 3.7–1350 m³/h
Head: 49–1800 m
Power: 3–1120 kW
Efficiency: 32%-84%
Pump weight: 78–3750 kg
Cavitation margin: 2.0–7.0 m
Price: 0.79–168,000
Suitable for conveying clear water at temperatures below 250°C, or non-corrosive liquids with physical and chemical properties similar to water, this pump is widely used in boiler feedwater systems in industries such as power plants, metallurgy, and heating. Its maximum head can reach up to 1,800 meters.
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Multistage pump
Horizontal Single-Stage Fire Pump
Product Overview
The DG-type multistage boiler feedwater pump is a horizontal, multistage, single-suction sectional centrifugal pump suitable for conveying clear water at temperatures below 250°C or non-corrosive liquids with physicochemical properties similar to water. It is widely used in boiler feedwater systems in industries such as power plants, metallurgy, and heating. The maximum head achievable by this pump can reach 1,800 meters. The pump casing of the boiler feedwater pump can be axially disassembled along the axis. For the DG85-80×8 model, the suction port is oriented vertically upward, and the discharge port is also oriented vertically upward, perpendicular to the pump’s central axis. When viewed from the drive end, the rotation direction of the boiler feedwater pump is clockwise. However, Zhonglian Pump Industry, the manufacturer of multistage boiler feedwater pumps, can also produce pumps that rotate counterclockwise upon customer request; customers may specifically indicate their preference when placing an order.
↑DG150-50×5 Series Multistage Boiler Feed Pump↑
Parameter Range of DG-Type Multistage Boiler Feed Pumps
| ● Flow rate: 3.7–1350 m³/h | ● Head: 49–1800 m | ● Efficiency: 36-84% |
| ● Power: 3–2800 kW | ● Required Net Positive Suction Head: 2.2–8.3 m | ● Pump weight: 151–7384 kg |
Model Description for DG Multistage Boiler Feed Pumps
Model: DG12-50×3
DG — Multi-stage boiler feed pump
12—The design flow rate is 12.5 m³/h.
50—The design single-stage head is 50 m.
3—The series is of level 3
Structural Type of DG Multistage Boiler Feed Pump
The DG-type multistage boiler feedwater pump features a single-casing, single-suction, multistage horizontal sectional centrifugal pump design. The inlet of the multistage pump is positioned vertically, while the outlet points vertically upward. The specific structural details are as follows:
1. Stator Assembly: The stator assembly primarily consists of the front section, middle section, guide vanes, rear section, bearing housing, and balance chamber cover, all connected as a single unit by through bolts and nuts. The flanges on the sides of the front and rear sections are secured to the pump base using bolts and nuts.
2. Rotor Assembly: The rotor assembly primarily consists of an impeller, an impeller retaining sleeve, a balance sleeve, a balance disc, and a shaft sleeve. These components are secured to the shaft by small round nuts and are fixed in place using a flat key to prevent rotation. The entire rotor is supported by bearings at both ends. The rotor is directly connected to the motor via an elastic pin-type coupling. To compensate for thermal expansion, a toothed spacer is installed between the last-stage impeller and the balance sleeve; this component should be replaced during pump maintenance.
3. Balancing Mechanism: This pump is equipped with a hydraulic balancing device—a balancing disc—that can fully and automatically balance axial forces. The device consists of four components: the balancing plate, the balancing disc, the balancing sleeve, and the balancing stop sleeve.
4. Rotation Direction: When viewed from the motor end, the pump rotates clockwise.
5. Material of Parts: With the exception of DG85-80 and 200DG43 pumps, which are made of cast steel, all other pump components are made of cast iron.
6. Scope of the complete set: The package includes a pump, motor, check valve, gate valve, common base or self-contained base.
Material of Main Components for DG-Type Multistage Boiler Feed Pumps
| ● Inlet and outlet sections: ZG230-450 | ● Middle section: ZG230-450 | ● Guide vanes: QT450 |
| ● Impeller: QT450 | ● Spindle: 40Cr | ● Seal ring: QT450 |
| ● Bushing: HT250 | ● Balance disc: ZG2Cr13 | ● Balance ring: tin bronze |
Friendly reminder: Users can communicate with Zoomlion Pump Industry’s technical staff based on the on-site conditions and requirements to make a reasonable configuration.
Installation Steps for DG-Type Multistage Boiler Feed Pumps
1. Preparatory work
Before assembly, all pump parts—especially the precision-machined surfaces that fit together—must be thoroughly cleaned.
Count all the parts and classify and number them according to the assembly sequence.
2. Assembly of pump components
Pay attention to installing the middle sealing ring properly to prevent it from falling off.
Pay attention to aligning the guide vane anti-rotation pin correctly.
Tighten the through-bolt nuts on the pump body symmetrically to maintain proper tightening force. If the nuts are too loose, leakage may occur at the middle joint surface; if they are too tight, the stator components may become deformed. During assembly, the torque of the wrench should be approximately 5,550 Newton-meters. Tighten the through-bolts symmetrically.
After the shaft is basically tightened, use a dial indicator to check that the parallelism between the front and rear sections should be ≤0.1 mm. 1.3 Measure the total axial runout of the rotor; it must meet the requirements specified in the drawings.
Install the front cover, the low-pressure end cover bearing, and the lower bearing shell, then lift the shaft into the center position.
Use dedicated lifting tools and a dial indicator to check the runout of the balance sleeve end face; it should meet the requirements specified in the assembly drawing.
Assemble the rotor components and tighten the lock nuts. The measured axial clearance after installing the balance disc shall meet the requirements specified in the general assembly drawing.
When installing the end caps, tail cap, bearing housing, and the top and side clearances of the bearing bushings, the values shall conform to the specified requirements for bearing bushing quality.
Adjust the centers of the bearing shells on both sides, and after adjustment, tighten the adjusting nuts.
3. Assemble the thrust bearing
For the assembly of thrust bearing components, scrape and lap the babbitt bearings according to the requirements for bearing components. During assembly, the thrust pads should rotate smoothly and freely. 1.9.2 After installing the thrust bearing, the axial clearance between the balance disc and the balance sleeve shall comply with the requirements specified in the general assembly drawing, i.e., a clearance of 0.04 to 0.08 mm. Adjustment of this clearance shall be achieved using adjustment rings.
After adjusting the clearance, install the thrust bearing and thrust disc, then tighten the lock nut.
The pump body and pump cover form the working chamber for the impeller. On the inlet and outlet flanges, there are threaded holes for installing vacuum gauges and pressure gauges. At the lower part of the pump body, there is a threaded hole for draining residual water.
The impeller is a single-suction, closed-type design. A balance disc is provided to counterbalance most of the axial forces, while a thrust bearing is installed to accommodate any remaining minor axial thrust. The arrangement of these bearings ensures that the shaft remains in a stable, tensioned state. Before assembly, each impeller must undergo rigorous static balancing verification to guarantee smooth operation.
The pump shaft is supported by two Babbitt alloy sliding bearings, which are housed in bearing housings within the pump suspension and lubricated with thin oil.
A sealing ring is installed on the pump body, which can enhance the pump’s volumetric efficiency. On the other hand, it also prevents high-pressure water from flowing back into the suction chamber and disrupting the inlet flow field, thereby ensuring the pump’s reliable suction performance.
The shaft seal is typically a soft packing seal. During pump operation, a small amount of medium can be routed to the stuffing box, or external cooling and lubricating water can be supplied to serve both as a water seal and for cooling and lubrication purposes. Upon user request, the packing seal can be replaced with a mechanical seal.
The clearance between the thrust bearing housing and the thrust disc is adjusted using shims to ensure compliance with the total assembly drawing’s requirements for the thrust bearing clearance.
Product Parameters
Performance Parameters of DG Multistage Boiler Feed Pumps
| Model Series |
Flow range (m³/h) |
Head range (m) |
Efficiency range (%) |
Matching power range (kw) |
| DG6-25 | 3.75–7.5 | 70.35–320.3 | 36~49.5 | 5.5 to 18.5 |
| DG6-50 | 3.75–7.5 | 144~624 | 28~30 | 15~55 |
| DG6-80 | 3.75–7.5 | 225~982 | 32~36 | 15~75 |
| DG12-25 | 7.5–15 | 68.3–325.3 | 43.3–52.1 | 7.5–30 |
| DG12-50 | 7.5–15 | 142.7~635 | 30.6–44.6 | 18.5~75 |
| DG12-80 | 7.5–15 | 225~982 | 37~40 | 30~132 |
| DG25-30 | 15~30 | 77.7~418.8 | 55.2–56.9 | 15~55 |
| DG25-50 | 15~30 | 144~618 | 44~54 | 22~110 |
| DG25-80 | 15~30 | 228~1013 | 47–56 | 37~160 |
| DG46-30 | 30~55 | 76.2~429 | 60~66.8 | 22~90 |
| DG46-50 | 30~55 | 138.3–658.8 | 53.6–64.5 | 37~160 |
| DG46-80 | 30~55 | 228~1056 | 59–65 | 55~250 |
| 80D12 | 21.6–39.6 | 19~129.6 | 69–75 | 4~18.5 |
| DG65-80 | 50~75 | 228~1056 | 60–67 | 75~315 |
| 100D16 | 37.6–72 | 20.4~178.2 | 66~73 | 7.5~37 |
| DG85-45 | 55~100 | 121.8~612 | 64.2–70.4 | 55~200 |
| DG85-67 | 55~100 | 186.9~888 | 56.1–68.4 | 90~315 |
| DG85-80 | 55~100 | 228~1056 | 59~71 | 110~450 |
| DG85-150 | 55~100 | 429~1872 | 53~60 | 220~900 |
| DG100-25 | 72~119 | 46~270 | 63.4–69 | 30~132 |
| DG100-55 | 85~120 | 147~708 | 64.4–68 | 90~315 |
| DG120-50 | 96~140 | 126.9~654 | 72~78 | 90~280 |
| DG120-67 | 96~140 | 183–840 | 62–71 | 110~450 |
| DG120-80 | 96~140 | 216~1056 | 61.6–70.4 | 132~560 |
| DG120-100 | 96~140 | 261.6–1320 | 69.5~73 | 220~900 |
| 125D25 | 72~119 | 35~230.4 | 70.5–77.5 | 22~90 |
| DG150-50 | 120~180 | 127.5–660 | 72~75 | 110~400 |
| DG150-80 | 120~180 | 228~1056 | 65~75 | 185~710 |
| DG150-100 | 120~180 | 261.6–1320 | 69.5~73 | 220~900 |
| DG150-130 | 120~180 | 354~1644 | 62.5~64 | 315~1250 |
| DG155-30 (150D30) |
100~185 | 81.6–400.8 | 65.5–73.2 | 75~250 |
| DG155-67 | 100~185 | 179.4–895.2 | 63–74 | 132~560 |
| DG200-50 | 132~240 | 135~696 | 78–81 | 132~500 |
| DG200-80 | 132~240 | 216~1044 | 70.9~75 | 220~900 |
| DG200-100 | 132~240 | 252~1356 | 70~76 | 250~1000 |
| DG280-43 (200D43) |
185~335 | 116.1~564 | 70.5–76.7 | 160~630 |
| DG280-65 (200D65) |
185~335 | 184.5~816 | 63.3–74 | 250~1000 |
| DG280-95 | 185~335 | 273~1200 | 68~72.5 | 400~1600 |
| DG280-100 | 185~335 | 279~1248 | 58.6–72.6 | 400~1600 |
| DG300-65 | 240~350 | 180~828 | 69.2–69.5 | 315~1120 |
| DG360-40 | 300~440 | 106.5~504 | 77~80 | 185~710 |
| DG360-60 | 300~440 | 157.5–768 | 71~74.5 | 355~1250 |
| DG360-95 | 300~440 | 267~1224 | 70~73 | 500~2000 |
| DG420-95 | 350~500 | 263~1192 | 67.9–71 | 560~2240 |
| DG450-40 | 330~500 | 112.5~528 | 73.9–76.9 | 220~1000 |
| DG450-60 (250D60) |
335~500 | 162.9–765.6 | 74.1–78.9 | 355~1400 |
| DG450-95 | 335~500 | 267~1200 | 72~75 | 560~2240 |
| DG500-57 | 375~555 | 109.6–717.6 | 69.7–82.6 | 220~1400 |
| DG550-40 | 400~600 | 76~528 | 75.1–78.4 | 185~1120 |
| DG550-50 | 400~600 | 95~660 | 75.1–77.8 | 220~1400 |
| DG550-95 | 400~600 | 182~1230 | 70.9–72.4 | 450~2800 |
| DG580-60 | 450~640 | 113~780 | 75.5–76.8 | 280~1800 |
| DG580-100 | 450~640 | 190–1284 | 70~74 | 500~2800 |
| DG600-60 | 450~710 | 104~780 | 79–82 | 280~1800 |
| DG600-85 | 450~710 | 162~1092 | 72.4–73.6 | 450~2800 |
| DG650-80 | 540~715 | 154~1005 | 73.5–75.5 | 450~2800 |
| DG650-100 | 540~715 | 193~1256 | 79.2–83 | 500~2800 |
| DG720-60 | 550~850 | 106.8~738.1 | 79.2–82.4 | 355~2240 |
| DG720-80 | 550~850 | 149~931.8 | 72.9~76 | 630~2800 |
| DG720-100 | 550~850 | 186~1059 | 76.5–84 | 560~2800 |
| DG800-80 | 620~900 | 150~951.5 | 73–81 | 500~2800 |
Friendly reminder: Click on the specific model series above to view more detailed specifications and performance curves, among other information.
Why choose us?
Changsha Zhonghlian Pump Industry Co., Ltd. was founded in 1989 and was independently established after the restructuring of Changsha Water Pump Factory. It is a comprehensive national high-tech enterprise integrating design, research and development, manufacturing, and service. The company was listed on the Hunan Provincial Equity Exchange on December 31, 2019, with the abbreviation "Zhonghlian Pump Industry" and the equity code: 600275HN. It is currently a key backbone enterprise in China's centrifugal pump industry and one of the major professional manufacturers of multi-stage pumps in the country. The headquarters is located in Changsha City, Hunan Province, a historical and cultural city in China.
Square meters of land area
100% factory pass rate
Square meters of land area
100% factory pass rate
Q
What is your typical delivery time?
A
Models in stock can be shipped the next day at the latest. All others are custom-made, with lead times generally ranging from 7 to 90 days depending on the product size and project specifics. Please contact our sales manager for details: 0731-88632200 。
Q
Do you have centrifugal pumps in stock?
A
Centrifugal pumps come in numerous models and configurations. Except for a small number of high-volume, standard models that are in stock, the vast majority are not stocked and are customized products. We need to select a pump based on your site's flow rate, head, media temperature, pH value, and installation conditions, etc., to determine the pump model and configuration before we can submit an order to the factory for production.
Q
What information should I provide when requesting a quote?
A
Generally, to obtain an accurate quotation, we recommend providing us with the following information: pump flow rate, head, on-site operating voltage and frequency, temperature, pH value, and solid particle content of the fluid being conveyed, and on-site installation conditions (horizontal or vertical installation), etc.
If you are not sure, don't worry, our business managers will assist you in determining this.
Q
What products do you mainly produce?
A
Zhonglian Pump Industry manufactures various large industrial centrifugal pumps. Main products include: self-balancing multi-stage pumps, multi-stage centrifugal pumps, single-stage centrifugal pumps, split-case pumps, chemical pumps, submersible pumps, pipeline pumps, long-shaft pumps, condensate pumps, etc.
Q
Why is it so slow to get a price quote?
A
Because centrifugal pumps are non-standard customized products with many models, the price range is also very large. Even for the same model, the price difference is also very large due to different materials and configurations. Taking the most common water pump accessory—the impeller—as an example, the price of a stainless steel impeller is several times that of a cast iron impeller. Therefore, we need to clarify the relevant information to give you an accurate price. Normally, if you provide relatively comprehensive information, we can quote within 5 minutes.
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