Product Overview

The BMD(A)-type pump is a horizontal, multistage, centerline-supported, double-casing centrifugal pump designed to meet API 610 12th Edition standards. Its dual-casing construction minimizes leakage risks and enhances operational safety. The innovative "core-in-cassette" design allows for rapid maintenance—the internal pump bundle can be extracted without disconnecting inlet/outlet piping, significantly reducing downtime.

Parameter Range

Design Standard: API 610 12th Edition

Flow Range: 10–1,000 m³/h

Head Range: Up to 4,000 m

Max. Design Pressure: 45 MPa

Speed Range: 3,000–6,000 RPM

Temperature Range: -80°C to +450°C

Structural Features

BB4 Core Bundle Structure Diagram                  BB3 Core Package Structure Diagram

First-Stage Impeller

Designed with low suction-specific speed standards.

Large-sized pumps may adopt a first-stage double-suction design for high anti-cavitation performance (low NPSHr).

Pump Casing

Flanged design:

Low-pressure side: Connected to the barrel via double-end studs and nuts.

High-pressure side: Connected to the barrel using super nuts.

Wear Rings

Replaceable impeller wear rings and casing wear rings.

Material, hardness, and surface hardening methods can be selected based on pump material and application.

Axial Force Balancing

Balance drum structure.

Triple-clearance balancing mechanism (drum-disc-drum).

Mechanical Seal

Compliant with API 682 standards.

Single or double seals, pressurized or non-pressurized design.

Auxiliary sealing system (atmospheric side) may use non-contact dry gas seals.

Drive-End Bearing

Labyrinth seal or mechanical oil seal.

Lubrication: Oil ring or oil mist lubrication; cylindrical roller bearings or ball bearings.

For radial sliding bearings: Oil ring lubrication or forced lubrication.

Non-Drive-End Bearing

Labyrinth seal or mechanical oil seal.

Fan-cooled, oil ring or oil mist lubrication; tapered roller bearings or double-row angular contact ball bearings.

Thrust bearing (bidirectional load capacity) with forced oil lubrication.

Pump Cartridge Unit

BMD Type (BB4 Cartridge)

Tie-rod connection for easy installation/removal.

Guide vanes and impellers can be hydraulically optimized for different operating conditions.

Sealing between stages: O-rings or metal-to-metal sealing.

Spacer segments can be added if structural constraints exist.

BMDA Type (BB3 Cartridge)

Axially split inner casing—allows full rotor removal for maintenance.

Symmetrical impeller layout for partial self-balancing of axial forces, reducing balance mechanism failure rates.

Closed impellers, key-driven (for HPT market pumps, impellers are interference-fit with axial fixation).

Stepped shaft design per stage, allowing free thermal expansion toward the discharge side.

Small pumps: Coupling, bearing housing, and seal chamber must be removed before extracting the inner cartridge.

Large pumps: Inner cartridge can be removed as a single unit (barrel diameter > bearing housing).

Barrel (Pressure Casing)

Centerline support for improved thermal stability and higher nozzle loads.

Cast pump bodies: Inlet/outlet flanges are cast integrally.

Forged pump bodies: Inlet/outlet flanges are welded and undergo NDT inspection.

For high-temperature service (>260°C):

Requires warm-up system.

Positioning/guide bases needed for thermal expansion management.

Optional acoustic enclosures or insulation layers for noise reduction.

Large-Diameter Shaft & Rotor

Low-stress design. 

Fully machined.

Full rotor dynamic balancing.

Application Overview

This product is primarily designed for high-pressure, high-temperature, and heavy-duty applications, especially in the following critical processes:

▲Water treatment plants & desalination facilities

▲Oil refineries

▲Petrochemical plants

▲Steel mill decoking & descaling systems

▲Boiler feedwater systems