Flowserve HHPX High-Suction-Pressure SWRO Pump

Flowserve HHPX end-suction pump for seawater reverse osmosis

The Flowserve HHPX is an end-suction, single-stage, radially split pump engineered for seawater reverse osmosis (SWRO) desalination where the pump itself sees a high suction pressure. Flowserve gives the main use as energy recovery device (ERD) boosters: the pump raises the pressure of the stream that leaves the energy recovery device so that it joins the main high-pressure feed. The flyer lists flows up to 4,000 m³/h (17,611 gpm), heads to 70 m, pressures to 90 bar and a temperature of 50 °C. Seven Star LLC supplies the HHPX in Oman and the GCC as an independent supplier in Muscat, a region where SWRO is the main source of potable water.

The HHPX is an overhung pump of the HPX lineage, not a multistage membrane feed pump. In an RO train it complements the main high-pressure feed pump. Flowserve groups it with the CSX multistage feed pump, the DMX-RO and the DS-RO auxiliary pump in its reverse osmosis portfolio.

HHPX naming and the SWRO duty it covers

HHPX technical specifications

How the HHPX supports energy-efficient SWRO

In a seawater RO plant the main feed pump delivers the full membrane pressure, and an energy recovery device returns most of the hydraulic energy of the brine to the incoming feed. The recovered stream comes back slightly below the required pressure because of losses in the device and membranes, and a booster pump brings it up to feed pressure. The HHPX is built for that position, where suction pressure is already high and efficiency matters because the pump runs continuously. Fully shrouded precision-cast impellers, single or dual volutes and non-metallic wear rings are the features Flowserve lists to raise efficiency and cut volumetric loss.

Materials are as important as hydraulics. Super-duplex stainless steel (A890 Grade 5A) with a pitting resistance equivalent of 40 or more is used to resist seawater corrosion, and alloy 885 is an option.

Where the HHPX fits in an RO plant

An RO train typically has intake and pretreatment pumps, a high-pressure feed pump, an energy recovery device with its booster, and product water pumps. Flowserve names the CSX and the DMX-RO as high-pressure feed pumps, the DS-RO as a plant-support pump for pretreatment, boosting and product water, and the HHPX as the booster for the ERD stream. The CSX page of this site covers the multistage membrane feed pump.

Selection and ordering checklist for the HHPX

• Boost flow and the head to be added, with the train arrangement and ERD type.
• Suction pressure at the pump, which defines the casing pressure class.
• Feed temperature, salinity and chloride content to confirm the super-duplex or alloy 885 choice.
• Discharge size and nozzle orientation; confirm size range against the current Flowserve data for your project.
• Driver size, speed and variable-frequency drive usage.
• Seal type and flush plan; bearing cooling arrangement.
• Required test standards and documentation.

Installation, commissioning and maintenance

Pumps in this duty should be installed on a rigid baseplate with careful piping alignment because the casing is subject to high pressure and nozzle loads. During commissioning, flush new piping to keep debris out of the pump and the membranes, check bearing temperature and the fan for the bearing housing, and verify seal flush flows. The back pullout assembly allows the rotor to be removed without disturbing the motor or the casing connections, which reduces downtime. Plan for wear-ring inspection at regular outages.

Typical applications of the HHPX in Oman and the GCC

SWRO plants in Oman, the UAE, Saudi Arabia and Kuwait supply municipal water and industrial users. The HHPX is relevant to ERD booster duty in such plants, and in upgrades that add energy recovery to older trains. Warm Gulf seawater and high salinity raise the corrosion demands on materials, which is why super-duplex and alloy 885 options matter.

Information to send with your HHPX RFQ

• Plant capacity, train arrangement and ERD model.
• Boost flow, head, suction and discharge pressure.
• Feed water analysis and temperature.
• Preferred material and the allowed size range.
• Driver and VFD arrangement.
• Delivery site, project standards and test requirements.

Site conditions in Oman for the HHPX

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

Documents and quotation

The Flowserve HHPX flyer is attached on this page. Send your duty data and we will confirm available documents, availability and lead time. Seven Star LLC is an independent supplier and does not claim any official status with the manufacturer.