Introducing the SHD and SHDG Series: a single-suction, multistage segmental type centrifugal pump, meticulously engineered for the optimized conveyance of water and liquids with similar physical and chemical properties—devoid of solid particles. The SHD pump expertly manages transmission fluid at temperatures below 80ºC, making it ideally suited for applications in mines, factories, and urban drainage systems. Meanwhile, the SHDG pump is designed to handle fluids at temperatures up to 105ºC, perfectly crafted for use as a boiler feed pump or for delivering hot water in various demanding scenarios.
Structural Features
The SHD and SHDG pump models are composed of four key components: the stator, rotor, bearings, and shaft seal, each playing a pivotal role in the pump's efficient operation.
1. Stator Part: This segment is primarily constructed from the inhalation, middle, and spit sections, along with guide vanes. These elements are securely held together by tension bolts, ensuring optimal performance. The SHD-type pump features a horizontal inlet and vertical outlet, while the SHDG type boasts both vertical inlet and outlet configurations.
2. Rotor Parts: Comprising the shaft, impeller, balance plate, bushings, and additional components. The shaft is critical as it transfers power to activate the impeller, while the balance plate ensures equilibrium of axial forces. Both ends of the shaft are fitted with replaceable sleeves for enhanced protection.
3. Bearing Part: This includes two types of bearings—rolling and sliding. Each type is designed to support and ensure the smooth operation of the pump.
Sliding Bearings: These consist of the bearing body, caps, dust disk, oil level gauge, and rejection mooring rings, utilizing thick oil for lubrication. Rolling Bearings: Composed of the main body, bearings, and gland, these employ grease for lubrication.
4. Shaft Seal Parts: Equipped with either a mechanical or packing seal, this section is comprised of a water segment, sealed body filler, and retaining ring components at the tail cover. The seal chamber is fortified by water, acting as a seal and providing cooling and lubrication. The SHD pump secures seal water from internal pressure, while the SHDG pump accesses cooling water from external sources. Crucially, seal water pressure must exceed the seal chamber's by 0.05-0.1MPa, with cooling water pressure at 0.15-0.3MPa.
Furthermore, the pump is directly powered by a prime motor through a flexible coupling, ensuring seamless operation. It rotates in a clockwise direction when viewed from the prime motor end.
Versatility Defined: The SHD, SHDG single-suction multistage segmental type centrifugal booster pumps are engineered for robust performance, capable of being driven by either an electric motor or a diesel engine, offering unparalleled flexibility and reliability in various applications.
In the realm of multistage centrifugal pumps, the challenge of managing high thrust, generated by impellers aligned in the same direction, is expertly mitigated by incorporating a thrust balance device. This ingenious mechanism, often in the form of a balance disc or balance drum, significantly reduces thrust to manageable levels, easily handled by a standard-sized thrust bearing. This ensures optimal performance and reliability in demanding applications.
The choice of impeller material is crucial and offers a range of robust options, including cast iron, cast steel, stainless steel, and bronze. Each material brings its unique strengths, ensuring the longevity and efficiency of the pump under various operational conditions.
Versatile and Adaptable Flexible Couplings
Setting themselves apart from their rigid counterparts, flexible couplings excel in accommodating movement such as vibrations and thermal expansion, without incurring damage. This capability makes them perfect for scenarios where unavoidable misalignment exists between the drive and pump shafts. Furthermore, their exceptional vibration absorption contributes to significantly reduced operating noise. While their complex design might suggest a higher initial cost, the benefits of flexible couplings are evident in the protection they offer to shafts and bearings, significantly lowering maintenance costs and extending the lifespan of the equipment.
We incorporate high-performance wear-resisting disc couplings or pin couplings, ensuring durability and reliability.
For years, packing seals have stood out as a highly popular sealing solution. These seals employ rope-like materials that wrap securely around the pump shaft, effectively filling dead space and minimizing fluid loss. However, as time progresses, wear can increase fluid loss, potentially impairing regular lubrication and requiring more frequent maintenance to sustain optimal functionality.
Mechanical seals have emerged as the preferred alternative to traditional packing seals, especially in applications where preventing leakage is paramount. These seals are engineered for durability, designed to withstand much more rigorous conditions than their predecessors. Utilizing multiple sealing points, basic mechanical seals effectively minimize leakage, ensuring reliability and peace of mind in various demanding environments.
| Flow rate |
6-1000m3/hr |
| Head rate |
25-650m |
| Speed |
1450-2900rpm |
| Medium temperature |
0-105 ºC |
| Diameter |
40-350mm |
Our Stainless Steel High Pressure Booster Pump is a pivotal component in pressure boosting systems. These systems are designed for scenarios that demand unwavering flow and pressure. Among the prevalent projects that typically harness a horizontal multistage pump are:
Mine dewatering - Ideal for efficiently removing water from mines, ensuring smooth operations and safety.
High density living - Perfect for supplying robust water pressure to high-rise buildings and densely populated areas.
Snow making - Essential for creating snow in ski resorts, providing consistent quality and performance.
Boiler feed systems - Vital for maintaining optimal water levels and pressure within boiler systems.
Reverse Osmosis - Ensures pure, clean water through efficient pressure-driven filtration.
Industrial applications - Suitable for a wide array of industrial uses, delivering reliable pressure and flow.
Condensate - Efficiently handles condensate return, optimizing energy use and system efficiency.
High pressure cleaning/wash down facilities - Delivers powerful and consistent cleaning pressure for superior results.
Jacking pumps for fire hydrant systems - Provides crucial pressure support in firefighting efforts, enhancing safety.
Irrigation and fire hose feed supply - Ensures steady water delivery for agricultural irrigation and emergency fire fighting.
Showers - Offers a luxurious and consistent shower experience with optimal water pressure.
Co generation - Supports co-generation systems with reliable pressure management for improved energy efficiency.
Spray - Ideal for applications requiring precise and consistent spray pressure.
Pressure Boosting - Essential for maintaining optimal pressure across various applications, ensuring efficiency and performance.
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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