What piping material is used in Desalination plants?
Desalination service typically specifies Super duplex F53 and F55 for high-pressure reverse osmosis circuits, duplex F51 on lower-chloride duty, Cu-Ni 90/10 and 70/30 for seawater intake and cooling, titanium Grade 2 for thermal plant heat e. Kalp Alloys manufactures these grades in Ahmedabad, India, with EN 10204 3.1 or 3.2 mill test certificates issued in its own name.
Key Takeaways
- Grades this sector specifies: Super duplex F53 and F55 for high-pressure reverse osmosis circuits, duplex F51 on lower-chloride duty, Cu-Ni 90/10 and 70/30 for seawater intake and cooling, titanium Grade 2 for thermal plant heat exchange, and Inconel 625 on the most severe positions.
- Standards applied: ASME B16.5 and EN 1092-1, ASTM A182 for duplex and super duplex forgings, ASTM B171 and B466 for copper-nickel, ASTM B381 for titanium, and ASTM A790 for duplex pipe.
- Documentation demanded: EN 10204 3.1 or 3.2, ferrite content measurement on duplex and super duplex, pitting resistance testing to ASTM G48 where the specification requires it, and impact testing on super duplex forgings.
- Kalp Alloys manufactures all of the above at its own plant in Ahmedabad, with certificates issued in its own name.
- Third-party inspection by SGS, BV, TUV or Lloyds can be witnessed before dispatch.
- Size range NPS 1/2 inch to 48 inch, Class 150 to 2500 and PN6 to PN64.
What makes Desalination service demanding
Desalination combines seawater, elevated chloride concentration, oxygenated flow and in thermal plants heat as well. Pitting, crevice corrosion and chloride stress-corrosion cracking are the governing failure modes.
Grades specified in Desalination plants
Super duplex F53 and F55 for high-pressure reverse osmosis circuits, duplex F51 on lower-chloride duty, Cu-Ni 90/10 and 70/30 for seawater intake and cooling, titanium Grade 2 for thermal plant heat exchange, and Inconel 625 on the most severe positions.
Selection is made circuit by circuit rather than plant-wide. The table below maps the common positions in a desalination plant to the material normally specified for each.
| Application | Material normally specified |
|---|---|
| Seawater intake and screening | Cu-Ni 90/10 and coated carbon steel for biofouling resistance |
| High-pressure RO feed | Super duplex F53 and F55 for chloride and pressure combined |
| Permeate and product water | A182 F316L where chloride has been removed |
| Brine rejection | Super duplex F55 and Inconel 625 on the most concentrated streams |
| Thermal plant heat exchange | Titanium Grade 2 tube and Cu-Ni 70/30 tubesheets |
| Chemical dosing circuits | F316L, Hastelloy C276 and titanium depending on the dosed chemical |
Standards this sector works to
ASME B16.5 and EN 1092-1, ASTM A182 for duplex and super duplex forgings, ASTM B171 and B466 for copper-nickel, ASTM B381 for titanium, and ASTM A790 for duplex pipe.
Both the dimensional standard and the material specification appear on a correct purchase order, because they govern different things. A line item reading “weld neck flange, 6 inch, Class 300, RF, ASTM A182 F316L, ASME B16.5” is unambiguous; one reading “6 inch stainless flange” is not.
Documentation Desalination buyers require
EN 10204 3.1 or 3.2, ferrite content measurement on duplex and super duplex, pitting resistance testing to ASTM G48 where the specification requires it, and impact testing on super duplex forgings.
Super duplex is specified for pitting resistance, and that resistance depends on ferrite balance and on the absence of intermetallic precipitation. Both are set during forging and heat treatment, not during melting, which is why ferrite measurement and G48 testing on the finished component are worth insisting on rather than accepting a mill certificate for the billet alone.
The full document pack, and how to read each block of the certificate, is set out on our EN 10204 mill test certificate page.
Supplying Desalination projects from Ahmedabad
Kalp Alloys is a manufacturer, not a stockist. Forging, machining and inspection run at our own facility at 5, Jay Vijay Industrial Estate, B/h. Akash Vikas Estate, Keval Kanta Road, Rakhial, Ahmedabad, so the heat number traces to our own record and the mill test certificate carries our name.
For a sector where the certificate forms part of an approval file, a validation record or a class submission, that difference is the whole argument. A certificate passed down a trading chain names a mill the buyer cannot query and did not choose.
Stock sizes dispatch in three to seven days. Made-to-drawing items carry a firm lead time quoted at order confirmation, and there is no minimum order on stock sizes.
Frequently Asked Questions
Super duplex F53 and F55 for high-pressure reverse osmosis circuits, duplex F51 on lower-chloride duty, Cu-Ni 90/10 and 70/30 for seawater intake and cooling, titanium Grade 2 for thermal plant heat exchange, and Inconel 625 on the most severe positions.
ASME B16.5 and EN 1092-1, ASTM A182 for duplex and super duplex forgings, ASTM B171 and B466 for copper-nickel, ASTM B381 for titanium, and ASTM A790 for duplex pipe.
EN 10204 3.1 or 3.2, ferrite content measurement on duplex and super duplex, pitting resistance testing to ASTM G48 where the specification requires it, and impact testing on super duplex forgings.
Yes. Inspection by SGS, BV, TUV or Lloyds can be witnessed at our Ahmedabad plant before dispatch, and the release note is issued with the EN 10204 3.2 certificate.
Yes. Non-standard bores, thicknesses, drilling patterns and facing finishes are produced to customer drawing. Send the drawing by email or WhatsApp at +91 81608 73937 and the technical team responds with grade and forging options.
No. There is no minimum order on stock sizes and trial quantities are accepted, so a buyer can verify material and documentation before committing to a project quantity.