Flowserve DMX API 610 BB3 Axially Split Multistage Pump

Flowserve DMX API 610 BB3 axially split multistage pump

The Flowserve DMX is an axially split, multistage, between-bearings pump built to API 610 type BB3. It is aimed at the toughest high-pressure, high-flow applications in oil, gas, power and water: pipelines, boiler feed, water injection, CO2 transport and injection, refinery process and amine treatment. With more than 10,000 units supplied and over twenty sizes, it is one of the most widely used pumps of its type.

Seven Star LLC supplies Flowserve DMX pumps in Oman and the GCC as an independent supplier in Muscat. A product brochure is attached on this page. The DMX is a family of sizes and variants, so the configuration is chosen from the duty rather than a single ordering code.

DMX technical specifications

How the DMX multistage design works

Liquid passes through a series of impellers on a single shaft, each stage adding head. In the DMX the impellers are arranged in opposed groups. This opposed mounting balances axial thrust inherently, so the thrust bearing carries little load.

The casing is double volute, which balances radial thrust. The two effects together reduce shaft deflection and vibration, and the inherent hydraulic balance also allows both seal chambers to operate at suction pressure. That prolongs seal life, since the seals are not exposed to the full discharge pressure.

The first-stage impeller is available in single- or double-suction form to suit the NPSH available, which is how the DMXD and DMXDH variants lower the required suction head.

DMX variants and mechanical features

The casing is supported near the centreline so alignment is maintained as temperature changes. Nozzles are integral with the lower half, so the top half can be lifted without breaking piping connections, and cap nuts on the parting flange make removal easier. The axially split centre bushing and channel rings allow the rotor to be inspected and dynamically balanced without dismantling, and each pump is tested before shipment. Replaceable wear rings control interstage leakage, with optional laser-hardened, HVOF-overlaid or non-metallic rings.

Bearings, packages and options for the DMX

Standard radial bearings are self-aligning anti-friction, with two single-row angular-contact thrust bearings and an oil-ring lubrication system with a constant-level oiler and sight glass. Alternatives include split sleeve radial with ball thrust, split sleeve radial with tilting pad thrust, and ball radial with ball thrust. Bearing cooling may be by air, water or product, lubrication by ring oil, pressure or oil mist, and bearing isolation and monitoring instruments are available.

Pump packages may include lube oil piping, seal systems, cooling plans, instrumentation and drive train mounting, on baseplates such as welded steel with a sloped gutter drain, sub-base, three-point or skid type. A double shaft extension is available for connecting an auxiliary pump or hydraulic turbine. The pump is also described as RedRaven-ready for remote condition monitoring.

Selection and ordering checklist for the DMX

• Flow, differential pressure and operating range; 50 or 60 Hz supply
• Liquid properties: density or specific gravity, viscosity, temperature, corrosivity, solids
• NPSH available, to decide between single- and double-suction first stage
• Flange class (600, 900, 1500 or 2500) and design pressure
• Material class, including any CO2, sour or amine service requirements
• Seal type and plan, bearing type and lubrication system
• Driver and speed, plus baseplate and package scope
• Test requirements and documentation

DMX installation, commissioning and maintenance

A multistage pump of this size needs careful installation: a rigid, grouted baseplate, piping supported independently, and alignment that accounts for thermal growth. Before start-up, vent the casing, check the lubrication system and warm the pump gradually on hot duties. Verify minimum flow protection, since a multistage pump overheats quickly if run against a closed discharge.

Because the rotor can be balanced and inspected without full dismantling, overhaul planning is more flexible. Maintain spares of wear rings, seals, bearings and gaskets, and send nameplate data with parts requests so we can match the right size and variant.

DMX applications in Oman and the GCC

The DMX is frequently chosen for crude and product pipeline boosting, boiler feed water in power and desalination plants, water injection for oil recovery, and high-pressure CO2 and amine services in gas processing. The DMX-RO variant is intended for desalination high-pressure feed, and the turbine versions can recover energy from high-pressure process streams.

Ambient heat, dust and humidity affect cooling and lubricant selection, so describe the site when sending the enquiry.

Information to send with a DMX RFQ

• Process data sheet or nameplate photo
• Variant required (DMX, DMXD, DMXH, DMXDH, DMXT or DMX-RO)
• Material class, seal plan and bearing preference
• Package scope: driver, baseplate, lube oil, instrumentation
• Delivery location and timeline

Site conditions in Oman for the DMX

Pump selection in Oman has to account for the site, not only the duty point. Process liquids and cooling water can arrive warm in summer, which raises vapour pressure and reduces the available NPSH, so check the NPSH margin of the DMX at the highest expected liquid temperature. Motors on outdoor skids also work in high ambient air, and their rating, enclosure and cooling should match that environment.

For hygienic and process plants in the Gulf, plan the spare parts that wear first, such as seals, O-rings and bearings, and keep the material certificates with the plant records. Sharing the fluid, temperature, flow, head and cleaning regime with the supplier at RFQ stage makes it easier to confirm that the DMX is the right configuration before the order is placed.

Documents and quotation

A DMX brochure is attached on this page for reference. Send the variant, size and duty data and we will prepare a quotation.

Seven Star LLC is an independent supplier in Muscat and is not the manufacturer; the brochure is general information and not a certified drawing.