Flowserve UZDL API 610 BB1 Two-Stage Axially Split Pump

Flowserve UZDL API 610 BB1 two-stage axially split pump

The Flowserve UZDL is an axially split, two-stage pump built to API 610 type BB1. Its distinctive feature is a double-suction first-stage impeller that reduces the net positive suction head the pump needs, followed by a second impeller that builds head. That pairing makes it a natural answer to high-pressure duties where the available NPSH is limited, which is why it is widely applied in pipeline and transfer service.

Seven Star LLC supplies Flowserve UZDL pumps in Oman and the GCC as an independent supplier in Muscat. A product brochure is attached on this page. The UZDL is a pump family, so size, materials and arrangement are defined from the duty rather than by a single ordering code.

UZDL technical specifications

How the UZDL double-suction first stage works

A double-suction impeller takes liquid from both faces. The two inlet streams balance each other axially and the larger combined inlet area lowers the eye velocity, which is the reason the first stage can run with less NPSH than a single-suction equivalent. Booster pumps that would otherwise be installed ahead of a high-pressure pump can often be avoided.

Both stages use double-volute passages, joined by an integral crossover. The double volute cancels most of the radial load that a single volute produces away from the best efficiency point, so shaft deflection and vibration stay low even at minimum flow. A stiff shaft that runs below its first critical speed adds to that stability.

UZDL casing, bearings and construction details

The casing is near-centreline supported, which maintains alignment as temperature rises. A confined gasket design gives metal-to-metal contact at the joint and avoids corrosion of bolts and nuts. Suction and discharge nozzles are integral with the lower casing half, so disassembly does not disturb the piping.

Where the UZDL fits and related Flowserve pumps

Flowserve lists the UZDL alongside other API designs: DVS and DVSH single-stage double-suction BB1 pumps for lower pressure, the DMX BB3 multistage axially split pump for higher pressures, the HDX and HED-DS BB2 radially split designs, and the WUC vertical double-casing pump. For this page, the practical neighbours are the DMX, which extends pressure capability, and the HED, which is radially split for higher temperatures.

The UZDL occupies a middle position: more pressure than a single-stage axially split pump, simpler than a multistage unit, and ideal where low NPSH is the constraint.

Selection and ordering checklist for the UZDL

• Rated flow, differential head and operating range; 50 Hz or 60 Hz supply
• Liquid, density, viscosity and temperature, including any water or hydrocarbon pipeline data
• NPSH available at the suction flange
• Flange class: 300, 600 or 900, and maximum suction pressure
• Bearing arrangement, lubrication method and cooling preference
• Seal type and plan: single, dual unpressurised or dual pressurised
• Baseplate type, driver and coupling; direction of rotation
• Material class and any special testing requirements

UZDL installation, commissioning and maintenance

Place the pump on a baseplate that has been grouted and levelled, then align the coupling to the driver and check that the pipe strain at the nozzles is acceptable. The integral lower-half nozzles mean that the upper casing and rotor can be removed without breaking the piping, which shortens an overhaul considerably. Fill and vent the casing completely before start, and run the bearing lubrication system through its checks.

In service, trend vibration, bearing temperatures, seal condition and the differential pressure. Keep spare wear rings, bearings, a mechanical seal and gasket kit available. Quote the nameplate data when ordering parts so that we can match the right revision.

UZDL applications in Oman and the GCC

The brochure lists hydrocarbon pipelines, gas scrubbing, water pipelines, firefighting and heavy-duty transfer as the main applications. In the region, that translates to crude and product pipelines, water transmission mains over long distances, and fire-water systems at refineries and terminals where reliable high pressure is essential.

Operators in Oman and the GCC should note the effect of heat and dust on bearing cooling and lube oil. Choose the cooling method and the bearing isolation level with the site climate in mind.

Information to send with a UZDL RFQ

• Nameplate photo or the process data sheet
• Duty point and the operating envelope (minimum and maximum flows)
• Flange class, material class and API 682 plan
• Package scope: baseplate, coupling, driver, lube oil system
• Quantity, delivery location in Oman or the GCC and timeline

Site conditions in Oman for the UZDL

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 UZDL 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 UZDL is the right configuration before the order is placed.

Documents and quotation

A UZDL brochure is attached on this page for reference. Send the model, size and duty data and we will prepare a quotation; the brochure is a general guide and is not a certified drawing.

Seven Star LLC is an independent supplier in Muscat and is not the manufacturer; final pump selection is confirmed on the basis of the duty data you provide.