Introducing the SHD and SHDG series of single-suction multistage segmental type centrifugal pumps, meticulously engineered to transport fluids akin to water without solid impurities. The SHD model is perfect for handling fluids with temperatures under 80 ºC, making it an ideal choice for mining, industrial plants, and urban drainage systems. Meanwhile, the SHDG model caters to fluids up to 105 ºC, serving excellently as a boiler feed pump or for delivering hot water in similar demanding scenarios.
Structural Features
The robust design of the SHD and SHDG pumps is composed of key components such as the stator, rotor, bearings, and shaft seal, ensuring optimal performance and reliability.
1. Stator Part: This section includes components like inhalation, middle, spit section, and guide vanes, which are firmly clamped with tension bolts to facilitate the pump's running mechanism. The SHD-type pump features a horizontal inlet and vertical outlet, while the SHDG model is designed with both vertical inlet and outlet for versatile applications.
2. Rotor Parts: Comprised of essential elements such as the shaft, impeller, balance plate, and bushings, the rotor parts ensure the pump operates efficiently. The shaft imparts power to the impeller, maintaining balance through the balance plate, while both ends feature replaceable shaft sleeves for added protection.
3. Bearing Part: Available in two types—rolling bearings and sliding bearings:
Sliding Bearings: Consisting of a bearing body, caps, dust disk, oil level gauge, and rejection mooring rings, these are lubricated with thick oil. Rolling Bearings: Comprising the main body, bearings, and gland, with grease lubrication ensuring smooth operation.
4. Shaft Seal Parts: Featuring either a mechanical seal or packing seal, these components, including the water segment and retaining ring at the tail cover, ensure a watertight operation. The seal chamber facilitates water sealing, cooling, and lubrication. For SHD pumps, seal water derives from internal pump pressure, while SHDG models use external cooling water. The seal water pressure surpasses the chamber by 0.05-0.1MPa, with cooling water pressure ranging from 0.15-0.3MPa.
Additionally, these pumps are driven directly by a prime motor through a flexible coupling, ensuring seamless clockwise rotation as viewed from the motor end, enhancing operational efficiency.
The versatile SHD and SHDG centrifugal booster pumps can be powered by either an electric motor or a diesel engine, offering flexible options to meet diverse operational needs.
In the realm of multistage centrifugal pumps, the significant thrust generated by impellers aligned in parallel necessitates an ingenious engineering solution. Enter the thrust balance device, such as a balance disc or balance drum, which expertly regulates the thrust to manageable levels for standard-sized thrust bearings, ensuring efficiency and longevity.
Our impellers are crafted from a selection of robust materials, including cast iron, cast steel, stainless steel, and bronze, offering durability and versatility to meet the demanding needs of any application.
Advanced Flexible Couplings
In contrast to rigid variants, flexible couplings offer an enhanced capability to endure movement such as vibrations and thermal expansion without sustaining damage. This adaptability makes them excellently suited for situations involving inevitable misalignment between drive and pump shafts. Their ability to absorb vibrations effectively also serves to significantly reduce operating noise levels. While they may entail a more intricate and costly design, the ultimate payoff comes in the form of maintenance savings. By shielding shafts and bearings from damage and premature wear, flexible couplings promise cost-effective long-term operation benefits.
Our offerings include wear-resistant disc couplings and pin couplings, tailored for durability and performance.
Packing seals have long stood as the go-to solution for sealing needs, deploying rope-like materials that snugly encircle pump shafts to curtail fluid loss. Over time, though, this material can wear down, leading to increased fluid loss and potential complications with lubrication or replacement procedures.
Mechanical seals have overtaken traditional packing seals in applications where leakage prevention is critical. These seals boast superior durability and are designed to endure rigorous conditions. By employing multiple sealing points, basic mechanical seals effectively minimize leakage, offering a robust solution for demanding environments.
| Flow rate |
6-1000m3/hr |
| Head rate |
25-650m |
| Speed |
1450-2900rpm |
| Medium temperature |
0-105 ºC |
| Diameter |
40-350mm |
Our High Pressure Multistage Electric Booster Pumps are the backbone of pressure boosting systems. These robust systems are engineered to ensure a consistent and steady flow, essential in demanding environments. Here are some of the key applications that benefit from the reliability and power of a horizontal multistage pump:
Mine Dewatering - Efficiently manage water levels in mining operations, ensuring safety and productivity.
High Density Living - Provide reliable water pressure in multi-story residential buildings.
Snow Making - Support snowmaking machines for winter sports and resorts.
Boiler Feed Systems - Deliver precise and reliable water flow to maintain optimal boiler function.
Reverse Osmosis - Enhance water purification processes with precise pressure control.
Industrial Applications - Meet the rigorous demands of various industrial processes.
Condensate - Efficiently handle condensate in HVAC and other systems.
High Pressure Cleaning/Wash Down Facilities - Ensure powerful and efficient cleaning operations.
Jacking Pumps for Fire Hydrant Systems - Provide crucial support in fire safety systems.
Irrigation and Fire Hose Reel Supply - Maintain water supply for agricultural and emergency fire services.
Showers - Ensure consistent and invigorating water pressure for domestic and commercial showers.
Co-Generation - Support combined heat and power generation for enhanced energy efficiency.
Spray - Optimize spraying processes across various sectors.
Pressure Boosting - Elevate pressure levels to meet specific demands across different applications.
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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