OMAL designs and manufactures in-house valves and actuators for reverse osmosis desalination plants (SWRO). As a single supplier of valves, actuators and accessories, it can cover the main phases of the plant, from seawater intake to post-treatment. The range includes the KRAVEN butterfly valve, the MAGNUM Split Wafer, THOR Split Body and ITEM 424 ball valves, AGO pneumatic actuators, also with integrated handwheel and epoxy coating, Heavy Duty actuators and accessories such as limit switch boxes, positioners and manual gearboxes.

Desalination, or desalinization, is the process that removes dissolved salts from water, particularly from brackish water and seawater, to obtain fresh water for civil and industrial use.

One of the main technologies used in desalination plants and industrial desalination equipment is reverse osmosis, which is also applied to seawater desalination (Seawater Reverse Osmosis, SWRO). In this case, water is forced at high pressure through membranes that retain dissolved salts and separate fresh water from brine.

In every phase of the cycle, from seawater intake to post-treatment, fluid control relies on valves, actuators and automation accessories. OMAL can supply these components as a single partner, providing complete and reliable solutions.

Our range of desalination valves includes the KRAVEN butterfly valve and the MAGNUM Split Wafer, THOR Split Body and ITEM 424 ball valves. For automation, we offer AGO pneumatic actuators, also with integrated handwheel and epoxy coating, and Heavy Duty actuators. Limit switch boxes, positioners and manual gearboxes complete the offering.

Why choose OMAL valves and actuators for desalination?

Choosing OMAL for an SWRO desalination plant brings three guarantees: a single partner for valves, actuators and accessories across the main phases of the process; components manufactured entirely in-house, with direct control over their technical characteristics; and simpler plant management, from product selection to automation.

A single partner for the entire reverse osmosis process

Our range for seawater desalination plants covers all the main phases of the process: seawater intake, pretreatment, high-pressure pumping, reverse osmosis, energy recovery and post-treatment.

Anyone designing or managing a desalination plant therefore has a single point of contact for both the valve, which concerns the process, and the actuator, which handles its automation.

Total production and control of technical specifications

Specialists in valves and actuators since 1981, we at OMAL design and manufacture both components in the same facility.

This allows us to keep their technical characteristics under control and to supply a valve-actuator package that is already coupled and sized. The actuator is selected based on the torque required by each valve, and the assembly is delivered ready for installation.

Simpler selection, automation and management

Relying on a single partner also means reducing the number of suppliers involved in the plant, which simplifies three stages of the work: selection, automation and management.

Selection takes place within a single range of valves, actuators and accessories. Automation is simplified because OMAL supplies the valve and actuator already matched. Finally, the management of components in operation is handled by a single point of contact.

The SWRO plant phases covered by OMAL

Reverse osmosis, including industrial reverse osmosis, does not end with water passing through the membranes. In reverse osmosis desalination plants that treat seawater, the desalination process comprises six main phases, all covered by OMAL solutions:

●      Seawater intake: water is drawn in through submerged pipes or coastal wells.

●      Pretreatment: an initial filtration removes suspended solids, sand, algae and other materials.

●      High-pressure pumping: the pretreated water is brought to the pressure required to pass through the membranes.

●      Reverse osmosis: the membranes retain dissolved salts, bacteria and impurities, separating fresh water from brine.

●      Energy recovery: the hydraulic energy of the brine, which leaves the membranes at high pressure, is reused to reduce energy consumption.

●      Post-treatment: the water is remineralized, disinfected and subjected to quality controls before distribution.

Our range of valves and actuators for desalination plants

The OMAL desalination series brings together industrial ball valves of several types and the KRAVEN butterfly valve. All of them can be automated with our pneumatic valve actuators and dedicated accessories.

KRAVEN, the wafer and lug butterfly valve

KRAVEN is our butterfly valve, available in wafer and lug versions with both PN and ANSI flanges. It covers the range from DN40 to DN300 (1"1/2 to 12"), with a cast iron body, a cast iron or CF8M disc and EPDM, NBR and FKM seals.

When combined with an AGO pneumatic actuator, it becomes an automated butterfly valve.

MAGNUM Split Wafer, the wafer ball valve with flanged connections

MAGNUM Split Wafer is a wafer ball valve with full bore, floating ball and connection flanges according to EN 1092-1 and ASME B16.5. The body is made of carbon steel A105 or A350 LF2, or of stainless steel 316.

Sizes range from DN15 to DN200 (1/2" to 8") in the PN 16-40 and ANSI 150-300 classes, while up to DN100 the valve also reaches PN 63-100 and ANSI 600. DN150 and DN200 are also available in cast stainless steel CF8M and come standard with a manual gearbox.

THOR Split Body, the flanged ball valve for the highest pressures

THOR Split Body valves are split body ball valves for demanding industrial applications, with floating ball and full bore, also available with reduced bore. They cover sizes from DN15 to DN200 (1/2" to 8"), in carbon steel, stainless steel 316 or cast stainless steel CF8M.

Every THOR is a flanged ball valve and operates from PN 16-100 and ANSI 150-600 up to ANSI 900-1500 in sizes from DN15 to DN25. These higher classes make it the high pressure ball valve of our desalination range.

ITEM 424, the 3-piece stainless steel ball valve

ITEM 424 is an investment-cast, three-piece stainless steel ball valve, two-way and full bore. Its three-section construction makes servicing easier on desalination plants that require frequent maintenance.

It covers the range from DN8 to DN100 (1/4" to 4"), with pressure up to PN 63. The body is made of stainless steel 316 (1.4408), the ends are threaded or welded (butt weld or socket weld), and the ball seals are made of PTFE, also available in RPTFE, CTFE and TFM1600. It operates from -20 °C to +180 °C and features an actuator mounting flange compliant with ISO 5211.

AGO, automation for quarter-turn valves

AGO is our quarter-turn rotary pneumatic actuator in aluminum, a scotch yoke actuator available in double acting versions from 8 to 8,000 Nm and spring return versions from 15 to 4,000 Nm. Coupled with our ball valves, it forms a pneumatic actuated ball valve ready for installation.

The series is also available in two special versions. The first, AGO Handwheel, features an integrated manual handwheel that acts on the actuator transmission: once the compressed air supply is disconnected, it allows the valve to be operated with a torque equal to the nominal torque. The second is AGO with epoxy coating, which can be requested in both double-acting and spring-return versions.

Heavy Duty, for the highest torques

Heavy Duty actuators are scotch yoke pneumatic actuators in carbon steel, available in double acting and spring return versions, with nominal torque from 2,000 to 32,000 Nm.

Limit switch boxes, positioners and manual gearboxes

Automation accessories complete the range.

Our Limit Switch Box units feature a visual indicator, are made of aluminum or technopolymer and are available in versions for potentially explosive atmospheres.

OMAL positioners are available in three versions: pneumatic, electro pneumatic and smart. The electro pneumatic positioner works with a 4-20 mA signal, while the smart version communicates via the HART protocol.

The manual handwheel gearboxes, in aluminum or cast iron, are declutchable.

Certifications for valves, actuators and accessories

Depending on the product, the OMAL range is available with Ex CE/UKCA, Pressure Equipment CE/UKCA, SIL up to SIL3, TA Luft & Fugitive Emission, Fire Safe and IECEx certifications.

These are product certifications, not process certifications: they depend on the individual component and the selected version, not on the desalination application.

FAQ: frequently asked questions about valves and actuators for desalination

What is desalination?

It is the process that removes dissolved salts from water, particularly from brackish water and seawater, to obtain fresh water. The main technologies are thermal processes and reverse osmosis: SWRO plants are based on the latter.

What does SWRO mean? How does a reverse osmosis desalination plant work?

SWRO stands for Seawater Reverse Osmosis, that is, reverse osmosis applied to seawater.

Seawater is drawn in and pretreated to remove suspended solids, sand and algae. It is then forced at high pressure through membranes that retain salts, bacteria and impurities. The energy of the outgoing brine is recovered, while the fresh water obtained is remineralized and disinfected before distribution.

Which OMAL valves and actuators are available for reverse osmosis desalination plants?

The OMAL range includes the KRAVEN butterfly valve, the MAGNUM Split Wafer, THOR Split Body and ITEM 424 ball valves, AGO pneumatic actuators (also in the AGO Handwheel and epoxy-coated versions) and Heavy Duty actuators. Limit switch boxes, positioners and manual gearboxes complete the automation.

Why rely on a single supplier for an SWRO plant?

Because it reduces the number of suppliers and simplifies the selection, automation and management of components. OMAL can cover the main phases of the process, from seawater intake to post-treatment, with valves, actuators and accessories, ensuring total production and precise control of technical specifications across multiple components.