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Seawater doesn't care
what the plant is called
The intake, outfall and pretreatment systems of a desalination plant handle the same fluid, at the same diameters, under the same design conditions as a power plant circulating water line. That is the work we have been building and installing.
DN600 to DN5000
Seawater and brine
AWWA C950 / BS 5480
Buried SN 2500 to 10000
Made in Vietnam
Scope of Experience
Delivered: Large bore seawater cooling water piping for power generation, fabricated and installed on site. Acid and chemical storage tanks and scrubbers.
Capability: Intake and outfall pipelines and pretreatment systems for seawater desalination plants, in GRP pipe and vessels.
How we supply: We work as a sub-supplier through EPC contractors, plant maintenance companies and equipment vendors. We do not approach end users directly, and we present references by industry, country and technical specification rather than by client name.
We have not yet delivered a desalination plant on its own. The fluid, the diameters and the design basis are the same as the seawater projects we have completed. Send us a specification and we will confirm in writing what we can cover.
Applications
Where GRP fits in an SWRO plant
Not the whole plant. The high pressure RO loop belongs to duplex stainless. GRP earns its place in the low pressure, large bore, corrosive sections either side of it.
GRP scope across an SWRO plant. Grey items sit outside our supply.
01
Intake and Outfall Pipelines
Seawater intake and brine outfall. Long buried runs at large diameter, which is where corrosion and cathodic protection cost the most, and where GRP shows the clearest advantage.
- DN600 to DN3000, filament wound
- Buried stiffness SN 2500 / 5000 / 10000
- Double bell coupling, lap joint or flange
- No cathodic protection, no marine growth on the bore
02
Pretreatment and Filtration Feed
Dual media filter vessels, UF feed headers and chemical dosing lines. Seawater plus oxidant and coagulant, which makes resin selection the whole question.
- DMF pressure vessels and cartridge filter housings
- Dosing lines for FeCl3, NaOCl, H2SO4 and SBS
- Backwash piping, reverse flow and vibration allowed for
- Vinyl ester with C-veil liner
Why We Can Do This
Conditions we have already worked in
We have no project labelled desalination. But every individual condition a desalination plant presents, we have built for.
CONDITION 01
Seawater, large bore, long runs
An intake or outfall line carries the same fluid at the same diameters as a power plant circulating water line, and is designed to the same basis.
Vung Ang 2 Thermal Power Plant Seawater cooling water line, GRP fabrication and site installation
CONDITION 02
Acid, chemicals, scrubbers
Pretreatment dosing lines handle hydrochloric acid, sulphuric acid and sodium hypochlorite. This is the work we have done longest.
Chemical plants, Japan and Korea HCl scrubbers, storage tanks and separators
CONDITION 03
Replacement in a running plant
Expanding an existing desalination facility or replacing aged pipework requires fabrication from field measurement, not from drawings.
Refinery and petrochemical complex, Vietnam Cooling water line replacement in a running plant
On the permeate side. Depending on the client, the product water system downstream of post-treatment may require potable contact certification such as NSF/ANSI 61. Where that applies it needs to be agreed in advance, so please tell us the requirement when you send the specification.
Why steel loses on the seawater side
A desalination plant handles nothing but seawater. Unlike plants where seawater appears in one system, here corrosion is not an exception, it is the baseline condition.
- 316L is not safe either pitting and crevice corrosion progress in chloride service
- Brine is worse concentrated salt passes through the outfall line continuously
- Buried cathodic protection an installation cost and then a permanent monitoring task
- Recoating there is no way to recoat an intake line without stopping intake
- Scale and flow loss a rougher steel bore means higher pumping power every year
GRP removes or sharply reduces all five. Comparing initial material price alone misses every one of them.
Standards
Applicable standards
AWWA C950
Fiberglass pressure pipe, water service
BS 5480
GRP pipes and fittings, water supply and drainage
ASTM D2996
Filament-wound FRP pipe
ASTM D3299
Filament-wound FRP tanks
ASTM D3262 / D3754
Buried GRP pipe, gravity and pressure service
ISO 9001 / 14001
Quality and environmental management systems
Where a project requires a standard not listed above, we will review the specification and confirm whether we can comply.
Start with capacity and the pipeline route
Tell us the daily output, the diameter and length of the intake and outfall runs, the burial depth and the pretreatment configuration. We will come back with which sections suit GRP and at what specification. Basic design stage is not too early.
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