Technical Resources

AL-6XN® Distillation Trays

In 1989 AL-6XN® Alloy was selected to fabricate nine trays in the main atmospheric crude oil distillation tower of a major refinery, replacing the previous trays made of Alloy 400.

Following a thorough testing regime AL-6XN® was selected because of its greater resistance to corrosion when handling higher sulfur crude oil and its low costs. It’s also much stronger than other alloys tested including Monel.

A lighter gauge of AL-6XN® was used to create the replacement trays, providing additional cost savings for the refinery.

The distillation trays made of AL-6XN® were replaced after ten years of continuous service, prior to AL-6XN® being used trays had to be replaced every 2 years. The trays function at around 93.33°C and are most susceptible to corrosion when a range of acids condense on the trays. AL-6XN® was needed to fight H2SO4, which would form during the processing of high sulphur crude and HCI.

AL-6XN® – Easy To Fabricate

AL-6XN® was also used to manufacture trays in a smaller tower at the refinery. To aid assembly the trays were manufactured in narrow sections, measuring 17ft in diameter.

High strength AL-6XN® can be sheared, bent and punched without any difficulty.

With a minimum room temperature tensile strength of 100,000 psi AL-6XN® is extremely resistant to a variety of acids.

Suitable For Other Applications

AL-6XN® has been used for many other applications due to its excellent resistance to chloride pitting and crevice corrosion.

Unlike other stainless steels this 24% nickel, 20.5% chromium and 6.2% molybdenum alloy contains a nitrogen addition for increased strength, metallurgical stability and localized corrosion resistance.

For more information or to buy this incredibly effective alloy feel free to contact us today! 

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