Introducing the SHD and SHDG Series: a line of single-suction, multistage segmental centrifugal pumps that deliver exceptional performance for conveying fluids. These pumps are expertly designed to handle water and other fluids with similar physical and chemical properties, all while ensuring no solid particles disrupt the flow. The SHD pump is the ideal choice for applications requiring transmission of fluids with temperatures up to 80 ºC, making it perfect for mines, factories, or urban drainage systems. Meanwhile, the SHDG pump takes efficiency one step further, accommodating fluid temperatures up to 105 ºC, making it the quintessential solution as a boiler feed pump or for hot water delivery and similar demanding scenarios.
Structural Features
The SHD and SHDG pump series are engineered with precision, featuring a robust assembly comprised of the stator, rotor, bearings, and shaft seal. Each component is meticulously crafted to ensure seamless functionality and long-lasting performance.
1. Stator Part: This essential component includes the suction, middle, spit section, and guide vanes, all clamped together with tension bolts to create a harmonious unit. The SHD pump features a horizontal inlet and vertical outlet, while the SHDG pump is designed with the innovative feature of both vertical inlet and outlet, adapting effortlessly to your system's needs.
2. Rotor Parts: Comprising the shaft, impeller, balance plate, and bushings, this assembly is the heart of the pump's operation. The shaft is responsible for transferring power to the impeller, ensuring efficient fluid movement. Axial force is countered by the balance plate, while both ends of the shaft are safeguarded by replaceable sleeves, enhancing durability and performance.
3. Bearing Part: The pumps are equipped with two types of bearings: rolling and sliding bearings, each selected for optimal performance in specific conditions.
Sliding Bearings: This assembly includes the bearing body, caps, bearings, dust disk, oil level gauge, and mooring rings, all lubricated with thick oil, ensuring smooth and stable operation. Rolling Bearings: Featuring a compact body, bearings, and gland, these are lubricated with grease for efficient performance.
4. Shaft Seal Parts: Featuring either a mechanical or packing seal, these components include a water segment and sealed body filler, supported by retaining ring components at the tail cover. The seal chamber liquid serves as a water seal, providing both cooling and lubrication. For the SHD pump, seal water is sourced from pressure water inside the pump, while the SHDG pump utilizes cooling water or ambient temperature water from outside the pump. It's essential to maintain the seal water pressure between 0.05-0.1MPa, with cooling water pressure ranging from 0.15-0.3MPa for optimal performance.
Additionally, the pump's operation is streamlined through direct drive by a prime motor using a flexible coupling, ensuring efficiency and reliability. It operates in a clockwise rotation as viewed from the prime motor end, contributing to its user-friendly design.
The SHD and SHDG single-suction, multistage segmental type centrifugal booster pumps offer versatility by being compatible with both electric motors and diesel engines, providing the flexibility you need for diverse industrial applications.
In the realm of multistage centrifugal pumps, our innovative design addresses the significant thrust generated by impellers aligned in the same direction. Our advanced thrust balance device, featuring a sophisticated balance disc or drum, masterfully reduces this thrust to manageable levels, perfectly complementing a standard-sized thrust bearing.
Our impellers are crafted from a variety of high-quality materials including cast iron, cast steel, stainless steel, and bronze, offering durability and performance tailored to your industrial needs.
The Ingenious Flexibility of Our Couplings
Unlike their rigid counterparts, our flexible couplings are engineered to accommodate movement such as vibrations and thermal expansion without damage. This makes them the perfect choice for applications with unavoidable misalignment between the drive and pump shafts. Their ability to absorb vibrations not only reduces excessive operating noise but also enhances operational efficiency. Although they feature a more complex design and higher initial cost, the long-term maintenance savings from protecting shafts and bearings make them an invaluable addition to your system.
Our selection includes wear-resisting disc couplings and pin couplings, engineered for durability and performance.
Packing seals have been a reliable sealing solution for many years. These seals employ rope-like materials that wrap around the pump shaft, effectively minimizing fluid loss. However, as time progresses, the material may wear, increasing fluid loss and potentially hindering lubrication and ease of replacement.
Designed for excellence, mechanical seals are the preferred choice over traditional packing seals in applications where leakage must be minimized. These seals offer superior durability and are built to withstand harsh conditions, using multiple sealing points to virtually eliminate any leakage concerns.
| Flow rate |
6-1000m3/hr |
| Head rate |
25-650m |
| Speed |
1450-2900rpm |
| Medium temperature |
0-105 ºC |
| Diameter |
40-350mm |
Our robust Cast Iron Multistage High Lift Water Pump, meticulously crafted by Shanghai Semhai Pump Co., Ltd., is indispensable in pressure boosting systems. These settings require unwavering flow and pressure, making our pumps the perfect choice for numerous substantial projects. Key applications for our horizontal multistage pump include:
Efficient Mine Dewatering
High Density Living Complexes
Advanced Snow Making Systems
Reliable Boiler Feed Systems
Sophisticated Reverse Osmosis Processes
Diverse Industrial Applications
Effective Condensate Management
High Power Pressure Cleaning/Wash Down Facilities
Jacking Pumps for Enhanced Fire Hydrant Systems
Irrigation and Fire Hose Supply Solutions
Innovative Shower Systems
Efficient Co-generation Processes
Precision Spray Applications
Dynamic Pressure Boosting Solutions
A. What are the multi stage pump parts?
The multistage pump parts are very similar to those of the standard Centrifugal pump except for the Multistage Centrifugal pump where the additional parts are diffusers which efficiently channel the fluid into the eye of the impeller or to the following stage. In the side channel pump, there are intermediate plates with the scalloped side channel and liquid parts.
In multistage centrifugal pumps, because of the high thrust that is generated due to the impellers facing in the same direction, there will be a thrust balance device i.e balance disc or balance drum which reduces the thrust to a level which can be managed by a standard sized thrust bearing.
B. How does a multi stage pump work?
A multistage pump operates by one impeller feeding into the next impeller and the number of impellers required depend on the discharge pressure requirement. Liquid enters the pump and then passes through the various number of impellers in a sequence from the left to right.
C. What are the applications and uses for multi stage pumps?
The applications for multi stage pumps are many and varied and can be used for delivering water to high rise buildings, reverse osmosis (RO), boiler feed water, spraying, high pressure cleaning, water works, heating, condensate, fuel delivery, oil and gas production, power generation & mining and other high pressure and temperature applications..
D. What are the different types of multi stage pumps?
Types of multistage pumps include;
Horizontal Multistage Centrifugal pump (above ground)
Vertical Multistage Centrifugal pump (above ground)
Submersible/Sump pump types
Side Channel pump
Combination pumps i.e Centrifugal low NPSH first stage with side channel additional stage.
Horizontal split case pump
Vertical Turbine pump
Sanitary Multistage pump
E. What are the advantages of using a multi stage pump?
If we were to compare the Centrifugal multi stage pump to a high pressure duty pump - the Centrifugal multi stage pump even though it is more complex and costly, it would probably be a better hydraulic fit, have a better efficiency and be more reliable. With its hydraulic modules, the ability to supply additional impellers and its ability to trim those impellers, the duty point can me met exactly without compromise. The selection is more likely to be close to 'BEP' and will run efficiently and reliably.
Multi stage pumps can be configured to have an interstage bleed off if there are multiple duty points required. It may be possible to run a multistage pump at a lower speed than a single stage centrifugal pump which may offer an efficiency advantage but it will certainly run much quieter which is an important consideration in today's world. A 3 dBA increase represents a doubling of sound as the sound scale is logarithmic.
F. What is difference between a single stage and a multi stage pump?
A single stage pump uses one impeller whereas a multi stage pump uses 2 or more impellers (some manufacturers use 80 or more impellers).
There are additional components in a multi stage pump which are required for channelling the fluid from the first stage to the following stage i.e diffusers.
Multi stage pumps have a thrust balance device and there may also be intermediate bearings (lubricated by the pumpage) to steady the shaft plus other minor differences.
G. How do you read a multistage pump curve?
You read a multi stage pump curve in exactly the same way as you read any other pump type curve however some manufacturers will publish single stage curves which means that this has to be multiplied out to establish the number of stages required, however be aware that the side channel pumps have their maximum power at zero flow and the power decreases with increasing flow which is the reverse of a centrifugal pump.
H. What is the difference between a vertical multistage pump and a horizontal multistage pump?
The main differences between a vertical multi stage pump and a horizontal multi stage pump are;
1.The orientation of the pump
2.The vertical multi stage pump is above ground and may be used where there are space limitations however the motor needs to be removed before maintenance can be performed.
3.Vertical multi stage pumps are used in some applications where the motor needs to be lifted from the sump so that the unit can be maintained. It is common in vertical pumps for the thrust load to be taken by the motor e.g. VTP turbine pumps which have electric motors specifically designed for this type of pump to eliminate the need for a thrust bearing in the pump resulting in less complexity and costs. VTP pumps can be produced with column lengths of more than 100 metres.
4.Horizontal multi stage pumps are mounted using feet which for high temperature applications are a special design to allow for thermal growth and thus avoid operating issues due to expansion and contraction. They would need to be aligned with the electric motor. On vertical pumps, the mounting is perhaps simpler i.e for sump pumps, a support plate would be fixed with standard bolting and generally no alignment is required as the motor is flanged and it is self aligning with the corresponding register.
I. Which type of multistage pump is more commonly used in industry?
The most common type of multi stage pump used in Industry is the horizontal multi stage pump and vertical multi stage pump (above ground) mounted centrifugal pumps. However, multi stage side channel pumps would also be relatively common along with the vertical turbine pumps.
SEMHAI can offer a full range of Flowserve's Multi stage pumps.We provide localised technical support & on-site service engineering to support your operational needs.
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