The SHD and SHDG series are exquisite single-suction, multistage segmental type centrifugal pumps that offer unmatched performance for fluid conveyance. These pumps are engineered to transport water or substances with similar physical and chemical properties, ensuring no solid particles interfere with their operation. The SHD pumps are adept at handling fluids with temperatures below 80 ºC, making them ideal for applications in mines, industrial settings, and urban drainage systems. On the other hand, the SHDG pumps are designed to manage fluids with temperatures up to 105 ºC, perfect for use as boiler feed pumps or for the delivery of hot water in comparable scenarios.
Structural features
The SHD and SHDG pumps boast a robust design crafted from four key components: stator, rotor, bearings, and shaft seal. Each part is meticulously engineered to ensure optimal performance and reliability.
1, Stator part: This essential component includes the inhalation, middle, and discharge sections, along with guide vanes. These elements are tightly secured with tension bolts to create a unified running part. The SHD pump features a horizontal inlet and vertical outlet, while the SHDG pump is equipped with vertical inlets and outlets, enhancing its flexibility for diverse applications.
2, Rotor parts: Comprising the shaft, impeller, balance plate, and bushings, these components work in harmony to ensure efficient operation. The shaft transmits power to the impeller, enabling it to perform seamlessly. The balance plate adeptly neutralizes axial forces, and the replaceable shaft sleeves at both ends provide added protection to the shaft.
3, Bearing part: Featuring two types of bearings, rolling and sliding, these components are essential for smooth pump operation:
Sliding bearings consist of a bearing body, caps, bearings, dust disk, oil level gauge, and rejection mooring rings, all lubricated with thick oil. Rolling bearings include the main body, bearings, and gland, which are maintained with grease lubrication, ensuring longevity and precision.
4, Shaft seal parts: Choose between mechanical or packing seals, comprised of a water segment, sealed body filler, and tail cover letter retaining rings. The seal chamber liquid performs multiple functions: sealing, cooling, and lubrication. The SHD pump derives seal water from the pump's pressure water, while the SHDG uses external cooling or normal temperature water. It is crucial that the seal water pressure exceeds the seal chamber by 0.05-0.1MPa, and the cooling water pressure ranges from 0.15-0.3MPa to ensure optimal sealing efficiency.
Engineered for seamless integration, the pump is directly driven by a prime motor through a flexible coupling, offering clockwise rotation as seen from the prime motor end. This design ensures consistent and efficient operation.
The versatile SHD and SHDG single-suction multistage segmental type centrifugal booster pumps can be powered by either an electric motor or a diesel engine, catering to a broad range of power supply preferences and applications.
In the realm of multistage centrifugal pumps, the high thrust generated due to impellers aligned in the same direction necessitates the inclusion of a sophisticated thrust balance device. This could manifest as a balance disc or a balance drum that meticulously reduces the thrust to manageable levels for a standard-sized thrust bearing, ensuring smooth and efficient operation.
The impeller material selection is vital for optimal performance and longevity. It can be crafted from robust materials such as cast iron, cast steel, stainless steel, or even the lustrous bronze, each offering unique benefits and resilience.
Durable and Versatile Flexible Couplings
Flexible couplings, unlike their rigid counterparts, are designed to gracefully accommodate movement, such as vibrations and thermal expansion, without incurring damage. This adaptability makes them ideal for scenarios involving unavoidable misalignment between drive and pump shafts. Moreover, they excel at absorbing vibrations, significantly reducing excessive operational noise. While these advanced features result in a more intricate and costly design, the protective benefits of flexible couplings in safeguarding shafts and bearings from damage and premature wear translate into substantial maintenance savings over time.
Our design incorporates wear-resisting disc couplings or pin couplings, ensuring durability and reliability.
Packing seals have long been the sealing solution of choice, employing rope-like materials that wrap around the pump shaft to fill dead space and minimize fluid loss. However, as the gland packing material wears over time, fluid loss may increase, potentially impairing lubrication and ease-of-replacement, essential for optimal functionality.
For applications where leakage must be strictly avoided, mechanical seals are the preferred choice over traditional packing seals. These modern seals are crafted for superior durability and resilience, designed to withstand rigorous conditions. With multiple sealing points, basic mechanical seals nearly eliminate leakage issues, ensuring reliable and efficient operation.
| Flow rate |
6-1000m3/hr |
| Head rate |
25-650m |
| Speed |
1450-2900rpm |
| Medium temperature |
0-105 ºC |
| Diameter |
40-350mm |
Our state-of-the-art Flexible Coupling Centrifugal Pump, engineered for high-pressure boiler feeding, excels in pressure boosting systems. These scenarios typically require a steady flow and consistent pressure, ensuring top-notch performance. Some of the most prevalent projects utilizing a horizontal multistage pump include:
Mine dewatering: Efficiently manage underground water by employing our advanced pump technologies.
High density living: Provide reliable water solutions for densely populated urban areas.
Snow making: Perfectly designed for the snow-making industry, delivering high performance at cold temperatures.
Boiler feed systems: Ensure optimal water supply to boilers with our precision pumps.
Reverse Osmosis: Enhance your water purification processes with our reliable pumps.
Industrial applications: Meet the rigorous demands of industrial operations with our robust pumps.
Condensate: Efficiently handle condensate return with our tailored pump solutions.
High pressure cleaning/wash down facilities: Enjoy superior cleaning performance with our high-pressure pumps.
Jacking pumps for fire hydrant systems: Ensure safety with our powerful fire hydrant pumps.
Irrigation and fire hose feel supply: Keep your irrigation and fire systems running smoothly with our dependable pumps.
Showers: Experience consistent water pressure in residential and commercial showers.
Co generation: Efficiently handle energy co-generation processes with our specialized pumps.
Spray: Achieve optimal spray operations with our high-efficiency pumps.
Pressure Boosting: Elevate your system's pressure with ease, utilizing our cutting-edge pump technology.
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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