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23 September 2021


Petrogas Piping has been a pioneer in sourcing and supplying special steel grade pipes, backed by deep market insights. We pay close attention to the market demand and required applications in the Oil & Gas, Petrochemical & Construction industries. These special steels entail intensive care in material handling; and Petrogas Piping is definitely experienced in managing such sensitive material shipment.

We have been supplying these special steels to various projects in the middle east and other parts of the world. Of note, this includes the Duplex steel, which essentially belongs to the family of stainless steel. They are referred to as duplex due to their metallurgical structure, which contains two phases in almost equal proportions (i.e. Austenite and Ferrite). This grade provides resistance towards chloride stress corrosion and chloride pitting corrosions along with higher mechanical strengths against normal 300 series stainless-steel grades, due to the higher chromium and moly contents.

Its application is mainly seen in the offshore oil and gas industry for pipework systems and in the petrochemical industry in the form of pipelines and pressure vessels. Depending on the resistance towards the pitting corrosions, the duplex steels are classified as Standard Duplex, Super Duplex and Lean Duplex grades.

  • While Lean-Duplex (22-27), is of lower side of the range of duplex grades with lower PREN as close as standard 300 series, yet it has typical application utility in construction industry due to its higher mechanical strengths.
  • Duplex Steel (28-38), on the other hand, is of the mid-range grade with intermediate PREN and is commonly available in the Oil & Gas and Petrochemical industry.
  • Lastly, Super Duplex (38-45) contains a higher corrosion resistance, higher PREN and strength, but is more difficult to process the steels due to the higher contents of CrNiMoNand even W. This also requires specialized manufacturers to control the steel chemistry to maintain a good balance and achieve the required PREN.

The commonly used are Duplex and Super Duplex grades in Oil and Gas & petrochemical industry and are specially designed considering the applications. For a better understanding of the Duplex grade pipes, we recommend our clients to connect with us.

 In case of the ‘Duplex and Super Duplex Pipeline’ products purchase and partnership please contact us’ for your requirements. We have new inventory ready to leave the shelves immediately.