Power & Desalination supply in Oman

The baseline transmission grade. X52 balances weldability against pressure rating, which is why it remains the default for gathering lines, utility piping and plant interconnects where wall thickness rather than yield strength drives the design.

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.

Weathering structural plate. Copper, chromium and nickel additions let a dense, adherent oxide patina form that seals the surface, so the structure can be left unpainted and the maintenance coating cycle disappears.

Titanium and niobium stabilised austenitic grades. The stabilising addition ties up carbon so the steel resists intergranular corrosion after prolonged exposure in the 425-815 C sensitisation range.

Carbon pressure vessel plate for moderate and lower temperature service. The lower carbon of Grade 60 gives better formability and weldability than Grade 70, which suits cold-formed heads, thin shells and plant where notch toughness matters more than tensile strength.

The default carbon pressure vessel plate. Grade 70 carries the highest tensile of the SA516 family, and for sour service it is supplied with controlled sulphur, calcium treatment and HIC / SSC testing so wet H2S equipment can be built from a qualified plate rather than an upgrade alloy.

The high-temperature austenitic. 25Cr-20Ni gives scaling resistance to around 1035 C in continuous service, so 310S is the grade for furnace internals, radiant tubes and anything that lives in flue gas rather than in water.

A molybdenum-up step on 316L. Raising Mo to 3 - 4% lifts PREN to around 30, which buys real margin against pitting and crevice attack in pulp, scrubber and chloride service where 316L is borderline but duplex is more than the duty needs.

Titanium-stabilised 316. The titanium ties up carbon so the steel keeps its intergranular corrosion resistance after long exposure in the 425 - 815 C sensitisation range, and it holds higher creep strength than 316L in hot service.

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

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.

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.

Nickel-chromium-molybdenum alloy strengthened by niobium. Exceptional strength and corrosion resistance from cryogenic temperatures to 980 C without heat treatment.

Super duplex with PREN above 40 for the most aggressive seawater and sour service. S32760 (Zeron 100) adds tungsten and copper for enhanced acid resistance.

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.

Solid solution nickel-chromium-iron alloy with high resistance to oxidation, carburisation and chloride ion stress corrosion cracking at elevated temperature.

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.

Nickel-molybdenum-chromium alloy with tungsten, regarded as the most universally corrosion resistant alloy available for both oxidising and reducing media.

1.25Cr-0.5Mo-Si pressure vessel plate. The silicon addition improves oxidation resistance, making Grade 11 the common choice for hot wall vessels and hydrogen service up to around 550 C where full 2.25Cr strength is not required.

Iron-nickel-chromium alloy for high temperature strength with oxidation and carburisation resistance. The 32Ni-21Cr balance resists chloride stress corrosion cracking that austenitic stainless suffers, which is why it is standard for process heater and reformer tubing.

1Cr-0.5Mo pressure vessel plate. The economical Cr-Mo grade for moderate temperature pressure parts, widely used for separator and drum shells where creep and hydrogen resistance are needed but the duty is below the 2.25Cr range.

The creep-optimised version of Alloy 800. Controlled carbon plus a combined aluminium and titanium window of 0.85 - 1.20% gives far better creep rupture strength above 600 C, so 800HT is the grade for the hottest reformer and pigtail service rather than plain 800.

2.25Cr-1Mo pressure vessel plate — the refinery standard for hydroprocessing. The higher chromium and molybdenum push the Nelson curve limit well above Grade 11, which is why reactors, separators and hot wall equipment in hydrogen service specify it.

5Cr-0.5Mo plate. The chromium level lifts resistance to sulphidic corrosion and high temperature oxidation, so Grade 5 is specified for crude and vacuum unit hot sections where naphthenic and sulphur attack dominate.