At ChemiPetro, we have high performance pipe flanges in a range of superior alloys such as ferrite-molybdenum and super duplex, specially manufactured for use in the gas, oil and petrochemical industries. To understand why pipe fittings made from these alloys are superior to standard stainless steel, you must first understand what stainless steel is.

Basic stainless steel is itself a ferrite (iron) and chromium alloy, containing a minimum of 10% chromium which makes it resistant to corrosion and oxidation. If this percentage is increased, or other materials introduced (for example nickel or carbon) the physical characteristics of the alloy will be altered.

It is important this is taken into account when choosing products for industrial use. For this reason, stainless steel pipe flanges and other fittings are graded according to the mineral composition of the alloy (i.e. its crystalline structure) Set within narrow, clearly defined limits, this ensures the appropriate product is chosen for each application, and sets quality control standards.

The most common stainless steels are the austenitic or 300 series (also classified under the UNS system). These ferrite-chromium-nickel alloys make up over 70% of stainless steel products made. The most common austenitic grade is type 304 stainless steel (UNS 30400). This is not widely used in submerged or highly corrosive environments, as it has a higher risk of weld decay than, for example, type 321 – which has added titanium to reduce the risk.

Type 316 has added molybdenum for greater corrosion resistance. It is used in undersea pipelines and volatile chemical plants. Type 347 is made with added niobium, which desensitises pipelines during welding.

We at ChemiPetro manufacture a large range of pipe fittings in grades from 304 to 347H, to cover every industrial application.