Saudi Offshore Support: Delivered 120 m³/day SWRO System with Duty and Standby Trains

Saudi Arabia · Equipment delivered · Customer and vessel identity withheld

Does a package with two 5 m³/h seawater RO trains produce 120 or 240 m³/day? In this Saudi offshore-support delivery, one train is duty and the other is standby. The stated design production is 5 m³/h × 24 hours = 120 m³/day from one operating train. The two train ratings should not be added to advertise a 240 m³/day operating duty. KONCHE delivered the containerized equipment for a vessel serving an offshore oil platform; this case does not document its later installation or site performance.

Why did the project specify a shipboard SWRO package?

The project required freshwater for domestic and general industrial uses in an offshore oil operation. Its technical brief addressed ship motion, vibration, salt spray, restricted installation space and the vessel’s electrical interfaces. The project's intake design draws seawater from the middle or lower water layers to avoid the expected surface oil layer. On that design basis, the supplied SWRO scheme does not include a dedicated oil-removal unit. This intake choice is not a published measurement showing zero oil at the RO feed.

What does one duty train and one standby train mean here?

The project specification called for two 5 m³/h SWRO trains in one container. One train was intended to provide the design output; the second was intended as standby. KONCHE reports that the equipment was delivered. The project documents available for this case do not establish automatic changeover, actual uptime or simultaneous two-train production. Those functions should be checked in the approved controls and acceptance records before they are claimed.

Which seawater, power and vessel interfaces needed definition?

The specification called for seawater pretreatment followed by single-pass SWRO. It identified separate connections for seawater feed, filter backwash, concentrate, acceptable product water, off-spec product water and electrical power. It also specified 380 V, three-phase, 50 Hz supply, subject to the actual vessel electrical standard. The design brief required the seawater analysis and shipboard interfaces to be confirmed. The middle/lower-layer intake concept is known; its as-built depth and feed-water test results are not presented here.

The specified control functions included automatic membrane flushing at startup and shutdown; local pressure, flow, electrical and product-water conductivity readings; and alarms with shutdown on high pressure or insufficient feed pressure. These are specification requirements for the delivered package, not a published commissioning test result.

Why was no dedicated oil-removal unit included?

The base design takes seawater from below the surface layer where floating oil would be expected, so it omits a dedicated oil-removal unit. If actual intake conditions require extra protection, a coarse screen can be added for debris and dissolved air flotation (DAF) can be evaluated for oil removal. A screen alone is not an oil-removal unit. The US EPA's DAF guidance describes its use for oil and grease removal. These are optional additions, not part of this delivered base scheme.

Taking water below the surface reduces exposure to a surface slick but does not prove the intake can never encounter oil: ITOPF notes that oil droplets can disperse into the water column under some sea conditions. No oil measurement is available for publication in this case.

Was the delivered water verified as potable?

The technical specification named GB 5749-2022 as a drinking-water design target for domestic use. That reference is not a Saudi regulatory compliance statement. This case has no public product-water laboratory result or site acceptance record, so it does not claim verified potable-water performance. A comparable project should agree on the applicable local standard, sampling point and acceptance protocol before procurement.

What should an offshore buyer confirm before requesting a similar package?

Define the required net freshwater output and operating hours; whether standby means manual or automatic changeover; source-water analysis including any oil-risk assessment; vessel power and installation envelope; intended water uses and quality targets; intake, backwash, concentrate and product-water connections; and the factory and site acceptance evidence required. This keeps the duty rating, standby scope and delivered performance claims separate.

For related configurations, see KONCHE’s seawater desalination systems and containerized water treatment systems. To review a vessel-specific scope, request project support.