Introducing the SHD and SHDG series: these high-performing, single-suction multistage segmental centrifugal pumps are engineered for efficiency and reliability. Designed to transfer water or fluids with similar physical and chemical properties, free from solid particles, these pumps excel in diverse environments. The SHD pumps operate effectively at fluid temperatures up to 80 ºC, serving mines, factories, and urban drainage systems with precision. For more demanding applications, the SHDG pumps handle fluid temperatures up to 105 ºC, making them ideal for boiler feed and hot water delivery.
Structural Features
The SHD and SHDG pumps are meticulously crafted from four essential components: the stator, rotor, bearings, and shaft seal. Each part is engineered for optimal performance and durability.
1. Stator Part: The stator assembly includes the suction, middle, and discharge segments, along with guide vanes. These components are securely fastened together with tension bolts to ensure stability during operation. The SHD pump features a horizontal inlet and vertical outlet, while the SHDG variant boasts vertical inlets and outlets for enhanced versatility.
2. Rotor Parts: Comprised of the shaft, impeller, balance plate, and bushings, the rotor assembly is central to the pump's functionality. The shaft efficiently transfers power to the impeller, enabling smooth operation, while the balance plate expertly stabilizes axial forces. Replaceable shaft sleeves are positioned at both ends for added protection and prolonged service life.
3. Bearing Part: Our pumps utilize two types of bearings for superior performance: rolling bearings and sliding bearings.
Sliding bearings are composed of the bearing body, caps, dust disk, oil level gauge, and rejection mooring rings, all lubricated with thick oil to ensure smooth operation. Rolling bearings, featuring a main body, bearings, and gland, are proficiently lubricated with grease for seamless performance.
4. Shaft Seal Parts: Advanced sealing mechanisms include both mechanical seals and packing seals, comprising water segment and sealed body filler with retaining rings at the tail cover. The seal chamber is filled with liquid to facilitate water sealing, cooling, and lubrication. The SHD pump extracts seal water from inside, under pressure, while the SHDG model draws cooling and normal temperature water from outside. Seal water pressure must exceed the chamber by 0.05-0.1MPa, with cooling water pressure set between 0.15-0.3MPa.
Additionally, these pumps are driven directly by a prime motor via a flexible coupling, ensuring efficient and reliable clockwise rotation when viewed from the motor end.
The versatile SHD and SHDG pumps can be powered by either an electric motor or a diesel engine, adapting to your specific needs with remarkable efficacy.
Within the realm of multistage centrifugal pumps, the remarkable forces produced by impellers aligned in the same direction create considerable thrust. To masterfully manage this power, our pumps are equipped with an advanced thrust balance device, such as a balance disc or balance drum, which expertly reduces the thrust to a manageable level for standard-sized thrust bearings.
Our impellers boast versatility in materials, including cast iron, cast steel, stainless steel, and the distinguished bronze, each chosen to meet unique application needs with precision.
Ingenious Flexible Couplings
In contrast to rigid alternatives, flexible couplings offer the exceptional ability to accommodate subtle movements, such as vibrations and thermal expansion, without sustaining damage. This adaptability makes them perfectly suited for scenarios where inevitable misalignment exists between drive and pump shafts. They excel in vibration absorption, effectively diminishing excessive operational noise. Despite their intricate and costly design, the long-term maintenance savings they offer by protecting shafts and bearings against damage and premature wear are invaluable.
For superior performance, we employ wear-resistant disc coupling or pin coupling for optimal durability and efficiency.
For years, packing seals have stood as the quintessential sealing solution. With rope-like materials enveloping the pump shaft, they expertly fill voids and minimize fluid escape. However, as time progresses, the gland packing material may eventually wear, leading to increased fluid loss and potentially compromising the ease of lubrication and replacement required for optimal function.
In applications where leakage prevention is paramount, mechanical seals have become the favored choice over traditional packing seals. These advanced seals are engineered to withstand greater punishment and are far more durable. They incorporate multiple sealing points to effectively minimize any leakage concerns, making them an ideal choice for diverse and demanding environments.
| Flow rate |
6-1000m3/hr |
| Head rate |
25-650m |
| Speed |
1450-2900rpm |
| Medium temperature |
0-105 ºC |
| Diameter |
40-350mm |
Our High Quality Horizontal Electric Pump is an essential component in pressure boosting systems, designed to deliver a consistent flow and pressure, crucial for a variety of demanding applications. These pumps are indispensable in the following projects:
Reliable Mine Dewatering - Ensuring safe and efficient removal of water from mining sites.
Enhancing High Density Living - Optimizing water supply systems in urban environments.
Innovative Snow Making - Supporting ski resorts with advanced snow production capabilities.
Boiler Feed Systems - Providing precise water supply to boilers for optimal performance.
Advanced Reverse Osmosis - Ensuring clean, purified water with high efficiency.
Industrial Applications - Powering various industrial processes with superior reliability.
Efficient Condensate Management - Streamlining condensate handling for diverse scenarios.
High Pressure Cleaning/Wash Down Facilities - Delivering robust cleaning power where it's needed most.
Jacking Pumps for Fire Hydrant Systems - Ensuring rapid response and powerful water delivery during emergencies.
Irrigation and Fire Hose Feed Supply - Empowering effective irrigation and fire protection solutions.
Revitalizing Showers - Enhancing shower experiences with consistent water pressure.
Co-Generation - Facilitating combined heat and power systems with efficiency.
Spray Applications - Optimizing spray systems for various needs.
Pressure Boosting - Elevating water pressure for enhanced system 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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