Flowserve HPX API 610 OH2 Centerline Process Pump

HPX API 610 OH2 centerline-mounted process pump range

The Flowserve HPX is a horizontal, centerline-mounted, overhung process pump built to the OH2 category of API 610 and fitted with an API 682 seal chamber. It is the pump most refineries and petrochemical plants think of first when a hot, flammable or high-pressure service needs a single-stage overhung design. Seven Star LLC supplies Flowserve HPX pumps and related spares in Oman and the GCC as an independent supplier in Muscat, and this page describes the series so that you can prepare a clear enquiry.

HPX is a series name, not a single ordering code. The range covers discharge sizes from 25 to 457 mm (1 to 18 in.), rated flows up to 5,000 m³/h (22,014 gpm), heads up to 350 m (1,148 ft) and temperatures up to 450°C (842°F). Within that envelope there is a family of specialty configurations, listed later in this page, so the first step in any HPX order is to fix the duty point and the service rather than a catalogue number.

HPX technical specifications

How the HPX is built and why it matters in service

The casing is supported at the shaft centerline rather than at the feet. When the casing heats up it grows symmetrically around the shaft axis, so the pump keeps its alignment with the driver, which protects the bearings and the mechanical seal. The same support lets the casing carry nozzle loads beyond API 610 requirements, a practical advantage on hot hydrocarbon lines where piping stress is never zero.

Casing and cover meet metal to metal with a fully confined, controlled-compression gasket, which keeps the fit and the alignment repeatable after every overhaul. The impeller is a precision casting that is dynamically balanced and is held by a set screw and locknut. Because the rotating assembly leaves through the back, the motor and the suction and discharge piping stay in place when the pump is serviced.

The bearing housing was redesigned with an optimised inner slinger, a finned upper surface, a large oil sump and a top-side oil passage. Together they improve lubrication and heat dispersion, which is why many installations that previously needed cooling water can run without it. The new housing is interchangeable with earlier HPX models, so an existing pump can be upgraded without changing the rest of the installation. Multiple oil collectors also allow clockwise or counter-clockwise rotation, which helps when replacing pumps from other makers.

HPX specialty configurations and related variants

The HPX platform is extended by a set of configurations that share the same basic architecture but are tuned for particular duties. Quote these by name when you contact us, because the bearing system, casing and even the API category change between them.

Application-specific options include jacketed casings and covers for fluids that can solidify, an inducer for low NPSH available, a coke crusher with a cutter screw for coke particles in suspension, and a ringless impeller with a hardened rotating wear surface for services that wear impellers quickly.

Where the HPX fits in the plant and which parts relate to it

The HPX is typically specified as a process pump on crude, light and heavy distillate, reflux, bottoms, hot oil, boiler circulation and similar services. The listed industries for the series are petroleum refining, production and distribution, petrochemical and chemical processing, the gas industry, boiler circulation, water, reverse osmosis and desalination, biofuels, solar, high-temperature applications and general industry. The seal chamber accepts all API 682 seal types and flush plans, including dual pressurised and unpressurised cartridge seals, so the pump is often quoted together with its seal and support system. On the same site you may also need Flowserve mechanical seals, Durco valves for isolation and Limitorque actuators, which we can quote in the same enquiry.

The pump is described as RedRaven Ready, meaning it is designed to accept wired or wireless condition-monitoring sensors for predictive maintenance. The optional dual temperature sensors for each bearing are one example of instrumentation that is easier to specify at the order stage than to retrofit.

HPX selection and ordering checklist

• Duty point: rated flow, differential head, NPSH available and the full operating range including minimum continuous flow.
• Fluid: name, density, viscosity, vapour pressure, solids content and any tendency to polymerise, solidify or form coke.
• Temperature and pressure: pumping temperature, suction pressure and maximum discharge pressure, which decide between standard HPX, HPX-MP and HPX-H.
• Standards and flange class: API 610 edition, ASME Class 300 or 600, or ISO or JIS flanges.
• Seal: API 682 category, seal type and flush plan, plus whether a dual pressurised arrangement is required.
• Bearing lubrication and cooling: oil slinger, oil mist or fan cooling, and whether cooling water is available at site.
• Materials: API 610 material class for casing, impeller, shaft and wear parts.
• Driver and baseplate: motor power, 50 Hz speed, and the skid arrangement.

Installation, commissioning and maintenance of the HPX

Set the baseplate on a properly grouted foundation and check the coupling alignment hot as well as cold if the service temperature is high. Verify that the piping does not impose load on the nozzles beyond the vendor limits, even though the centerline casing tolerates more than the API minimum. Fill the bearing housing to the correct level before the first start and confirm the direction of rotation on the uncoupled driver. Open the seal flush and cooling lines before the pump is primed, and vent the casing completely, because a hot hydrocarbon pump that runs dry damages seal faces quickly.

During operation, track bearing temperature, vibration and seal pot or flush indications. The finned bearing housing and large sump extend oil-change intervals, but oil quality still needs regular checks in a dusty, hot environment. Renewable wear rings are the main replacement item, and the back pullout layout lets a workshop crew remove the rotating assembly without disconnecting the motor or the process piping. Keep a spare set of wear rings, gaskets, bearings and a cartridge seal for critical pumps, and quote the pump serial number when ordering parts so the correct hydraulic and material combination is identified.

Typical HPX applications in Oman and the GCC

In Oman and the wider Gulf, the HPX series suits refinery process units, petrochemical plants, gas treating, power plant boiler circulation and seawater reverse osmosis desalination, where very high ambient temperatures, dust and humidity add load to bearing lubrication and seal cooling. The enhanced heat dispersion of the bearing housing and the option of fan cooling are useful where cooling water is limited. For desert and coastal sites, material selection against chlorides and H₂S needs to be agreed at enquiry stage.

Information to send with an RFQ for an HPX pump

To prepare a correct quotation please send the pump series or variant (HPX, HPX-H, HPX-MP and so on), size and model if known, the data sheet or process conditions listed above, the API 610 edition and material class, seal specification, driver details, the project specification and the required delivery location. If you are replacing an existing pump, add the nameplate data and a photograph, because the HPX has a long list of predecessor designs and the original model code helps us identify the correct match.

Documents and quotation

A Flowserve HPX datasheet is attached on this page for reference. It covers the design features, variants and general operating limits; it is not a substitute for a pump-specific data sheet and curve.

Send us your duty point, fluid and project specification and Seven Star LLC will prepare a quotation for your HPX pump or spare parts, supplied from our base in Muscat to sites across Oman and the GCC.