Horizontal Multistage Pump

The VSM series horizontal multistage centrifugal pump is a heavy-duty, ring-section multistage water pump engineered for continuous high-pressure service. By mounting multiple impellers in series on a single shaft, this horizontal multistage pump delivers discharge heads up to 1000 meters within a compact, floor-mounted footprint. With a flow range of 1 to 270 m3/h and motor power from 0.37 to 200 kW, it is the preferred choice for boiler feed water, high-rise water supply, reverse osmosis systems, HVAC circulation, fire fighting and industrial process water transfer.

Manufactured by FILIPUSI, a professional multistage pump manufacturer and exporter in China since 2005, the VSM series is available with SS304, SS316L or duplex 2205 stainless steel wetted parts and supports full OEM and ODM customization. Every unit is performance-tested on our in-house hydraulic test bench before shipment.

What Is a Horizontal Multistage Centrifugal Pump?

How the VSM Multistage Pump Works, Step by Step

Step 1 - Suction: Liquid enters the suction branch and flows into the first-stage impeller eye.

Step 2 - First pressurization: The rotating impeller adds kinetic energy to the liquid; the guide vane converts this velocity energy into pressure.

Step 3 - Series staging: The liquid passes into the next impeller stage, where pressure is raised again. This repeats through every stage.

Step 4 - Discharge: After the final stage, the fully pressurized liquid exits through the discharge branch at the required high pressure.

Step 5 - Shaft sealing: A cartridge mechanical seal prevents leakage along the shaft without requiring external cooling water.

Product Structure and Main Components

The VSM industrial multistage pump is built from built to last, serviceable components. The numbered cross-section below corresponds to the parts list table. All wetted components can be supplied in stainless steel to suit corrosive or high-temperature media.

Key Features and Advantages

Every detail of the VSM stainless steel multistage pump is designed for reliability, efficiency and low lifetime cost. The main advantages are summarized below.

Performance Range and Curves

The VSM high-pressure multistage centrifugal pump covers a broad performance envelope. The table below summarizes the standard operating range; the full performance curves (Q-H, Q-efficiency, Q-power and NPSH) are supplied in the technical datasheet and are verified by actual test results.

Typical performance curves: head (H), efficiency (eta) and shaft power (P2) versus flow rate (Q).

Materials of Construction

Correct material selection is critical for pump life. FILIPUSI offers three standard material configurations for the VSM horizontal multistage water pump, plus custom options for special media.

Applications and Industries Served

The VSM horizontal multistage centrifugal pump is one of the most versatile pumps in industrial water handling. Its high-head capability and stainless steel construction make it suitable across the following sectors.

Boiler Feed Water High-pressure feed for industrial boilers and small thermal power plants.	High-Rise Water Supply Pressure boosting for tall buildings, hotels, hospitals and municipal water networks.	Water Treatment / RO High-pressure feed for reverse osmosis, ultrafiltration and desalination plants.	HVAC Circulation Chilled and hot water circulation in commercial buildings and district heating.
Fire-Fighting Systems High-pressure water supply for fire hydrant and sprinkler systems.	Industrial Process High-pressure cleaning, CIP, spraying and process fluid transfer.	Irrigation & Agriculture Long-distance water transfer, farm irrigation and greenhouse systems.	Mining & Oilfield Mine drainage and oilfield water injection with duplex material options.

Detailed Application Notes

Boiler feed water service: In boiler houses, the multistage pump delivers deaerated feed water against high boiler pressure. The VSM hot-water variant handles feed water up to 150 C, and the multi-stage design provides stable pressure even under fluctuating load. For medium- and high-pressure boilers, a dedicated boiler feed pump (DG series) is also available.

Reverse osmosis (RO) feed: RO membranes require a stable high inlet pressure. The VSM pump with SS316L or duplex 2205 wetted parts resists corrosion from permeate and concentrate, and the steady flow protects membrane life. A variable-frequency drive (VFD) is often paired for energy saving.

High-rise pressure boosting: For buildings above 50 meters, a single-stage pump cannot provide enough pressure. The VSM horizontal multistage pump, often installed in a duty-standby booster set, delivers consistent pressure to upper floors while keeping noise and vibration low.

How to Select the Right Multistage Pump Model

Selecting the correct horizontal multistage centrifugal pump requires matching the pump curve to your system duty point. Please provide the following information and our engineers will recommend the optimal model, stage count and motor power within 24 hours.

Model Coding Reference

The VSM model is coded as follows. Contact us for the complete model selection sheet and dimensional drawing.

VSM - [Port Size] - [Number of Stages] - [Material Code] - [Motor Power]

Example: VSM-50-6-B-15 means DN50 ports, 6 stages, SS316L material, 15 kW motor. (Please confirm with our datasheet before ordering.)

Installation, Operation and Maintenance

Proper installation and routine maintenance extend the service life of the multistage pump and preserve its efficiency. The following guidelines apply to the VSM series; full instructions are supplied in the operation manual.

Before Installation

• Check that the pump nameplate data (flow, head, power, voltage) matches the order and system requirements.
• Inspect the pump for transport damage; rotate the shaft by hand to confirm it turns freely without rubbing.
• Install the pump on a flat, rigid concrete foundation or steel baseframe; anchor bolts must be grouted securely.
• Align the pump and motor coupling carefully; maximum permissible misalignment is 0.05 mm.
• Install a gate valve on the suction side and a check valve plus gate valve on the discharge side.

Startup Procedure

1. Fully open the suction valve and close the discharge valve.

2. Vent air from the pump casing through the vent plug; ensure the pump is fully primed.

3. Start the motor and check the rotation direction (matches the arrow on the casing).

4. Gradually open the discharge valve until the desired operating point is reached.

5. Monitor pressure, current, vibration and bearing temperature during the first 30 minutes of operation.

Routine Maintenance

• Daily: Check pressure, flow, current, noise and leakage.
• Monthly: Inspect mechanical seal for leakage; lubricate bearings if grease-lubricated.
• Every 6 months: Check coupling alignment and motor insulation resistance.
• Annually: Overhaul the pump: inspect impellers, wear rings, shaft sleeve, bearings and mechanical seal; replace worn parts.
• Bearing temperature should not exceed 80 C; vibration velocity should remain below 4.5 mm/s.

Quality Control and Testing

At FILIPUSI, every horizontal multistage centrifugal pump passes a strict quality control process before it leaves the factory: Incoming material inspection: Spectrometer verification of stainless steel grades (SS304 / 316L / 2205). Casting inspection: Visual and dimensional check of all cast casings and impellers. Hydrostatic pressure test: Casing pressure tested at 1.5 times maximum working pressure for 10 minutes, no leakage. Performance test: Flow, head, power and efficiency measured on our 500 kW closed-loop test bench; test report available on request. Running test: No-load and load running to verify vibration, noise and bearing temperature. Final inspection: Painting, nameplate, accessories and documentation checked against the order.

In-house 500 kW hydraulic test bench: every pump is performance-tested before shipment.

Packaging, Shipping and After-Sales Service

Why Choose FILIPUSI as Your Multistage Pump Supplier?

Frequently Asked Questions (FAQ)

Q1: What is a horizontal multistage centrifugal pump used for?

It is used for high-pressure water transfer applications including boiler feed water, high-rise water supply and pressure boosting, reverse osmosis (RO) feed, HVAC circulation, fire-fighting systems, industrial cleaning and irrigation. Any application that requires higher pressure than a single-stage pump can deliver is a candidate for a multistage pump.

Q2: What is the difference between horizontal and vertical multistage pumps?

Horizontal multistage pumps have a horizontal shaft and floor-mounted baseplate. They offer easier maintenance access, better bearing support for high power and are preferred for heavy-duty, continuous operation. Vertical multistage pumps have a vertical shaft, occupy less floor space and are commonly used in compact booster sets and building water supply.

Q3: What is the maximum head of the VSM series?

The VSM series delivers a maximum head of 1000 m, with a flow range of 1 to 270 m3/h and motor power from 0.37 to 200 kW. The exact head depends on the number of stages and the selected model.

Q4: Can the wetted parts be made of stainless steel?

Yes. SS304 is standard, with SS316L and duplex 2205 available for corrosive or high-temperature media. Cast iron casings with stainless steel impellers are also offered for cost-sensitive clean-water applications.

Q5: Do you offer OEM and customization?

Yes. We support OEM branding (logo, nameplate, color) and full customization of material, voltage, frequency, flange standard, motor brand and control panel.

Q6: What is the warranty period?

We provide a 12-month warranty from the bill of lading date. During the warranty period, defective parts (excluding wear parts and damage from misuse) are replaced free of charge. Lifelong technical support and spare-parts supply are available after the warranty.

Q7: How long is the delivery time?

Standard models in stock ship within 7 to 15 days. Customized orders (special material, voltage or motor) typically take 20 to 35 days depending on quantity and specifications.

Q8: Can you provide a performance test report?

Yes. Every pump is performance-tested on our in-house test bench, and a test report (flow, head, power, efficiency, NPSH) can be provided on request. Material certificates are also available.

Q9: What information do you need to quote a pump?

Please provide: required flow rate, required head, medium and temperature, power supply (V/Hz), pipe diameter or flange standard, and quantity. With these details our engineers will select the correct model and send a formal quotation within 24 hours.

Q10: Do you supply spare parts?

Yes. We maintain a stock of common spare parts including mechanical seals, bearings, impellers, shaft sleeves, wear rings and couplings. Spare parts can be shipped together with the pump or separately at any time.

Related Products

Vertical Multistage Centrifugal Pump Compact footprint for building water supply and booster sets.

End-Suction Centrifugal Pump General-purpose water transfer and circulation.

Explore related pump series: VS Vertical Multistage Pumps | Inline Booster Pumps | VFD Water Supply Systems | End Suction Pumps | Double Suction Pumps

Technical resources: Boiler Feed Pump Selection Guide | All Technical Articles

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