Grade Finder

Normalised structural plate with guaranteed 27 J impact energy at -20 C. The J2+N condition gives consistent toughness and flatness through thick sections, which is why it is specified for welded structures, crane and bridge work and heavy fabrication in the Gulf.

The default seawater alloy. 90% copper with 10% nickel and a controlled iron addition builds a protective cuprous oxide film in seawater, and the inherent copper toxicity stops macrofouling — barnacles and mussels do not settle, so cooling lines stay clean without chlorination. Specified for ship and platform seawater systems, firewater ring mains and condenser tubing where the velocity stays below about 3.5 m/s.

The higher-duty cupro nickel. Tripling the nickel to 30% raises strength, erosion-corrosion resistance and the allowable seawater velocity to around 4.5 m/s, and lifts the service temperature well above 90/10. It is the grade for pump and valve-adjacent piping, hot brine and MSF desalination heat recovery, and any line where turbulence or sand loading would strip the film off 90/10.

The desalination variant of 70/30. Raising iron and manganese to about 2% each stabilises the protective film under high velocity, sand-laden and partly deaerated brine, which is exactly the duty inside MSF evaporator heat recovery and reject sections. Where 70/30 tubes thin at the inlet ends, C71640 holds.

The most widely used duplex grade. Roughly double the yield strength of 316L, allowing thinner and lighter sections while delivering far better chloride stress corrosion cracking resistance.

Nickel-copper alloy with outstanding resistance to flowing seawater, hydrofluoric acid and alkalis, and total immunity to chloride stress corrosion cracking.

The workhorse offshore and high-pressure grade. The higher yield allows a thinner wall at the same design pressure, cutting pipe weight on risers and long tie-backs, and X65 is the grade most often specified with sour service and HIC testing.

Molybdenum-bearing austenitic stainless steel. The 2-3% Mo addition transforms pitting resistance in chloride-bearing media, making 316L the baseline grade for marine and chemical service in the Gulf.

Commercially pure titanium, the industry workhorse. Fully resistant to seawater and oxidising chlorides with excellent formability and weldability.