06.04.2015

Difference berween stainless steel grades in distillation stills

Sometimes beautiful, shining stainless steel items that please our eyes suddenly get rusty when even a couple of months hasn't passed. How can it happen?

Different stainless (supposed to be) steel grades used for distillation stills

Sometimes beautiful, shining stainless steel items that please our eyes suddenly get rusty when even a couple of months hasn't passed. How can it happen? The point is that stainless steel has several grades which are virtually indistinguishable visually while their operation reveals this difference rather quickly.

Today stainless steel is marked not according to the Soviet GOSTs but according to the international classification AISI (The American Iron and Steel Institute) which regulates nickel and other additions contents in the alloy. The higher a nickel share, the higher are steel anti-corrosion properties. The most wide-spread are the following steel grades: AISI 304, AISI 201, AISI 430.

AISI 304 is the key grade in the stainless steel group containing at least 18 % of chrome and 8 % of nickel, the equivalent of the marking according to the Russian GOST is 08Х18Н10. Such nickel contents provides for formation of the oxide layer which makes steel resistant towards the influence of various chemical materials. Besides, such proportion of elements inside the alloy endows it with anti-ferromagnetic properties. Such properties make AISI 304 suitable for street fences ad rails as well as for swimming pools and food industry units. This is the most high-quality stainless steel grade and this is exactly the grade used in the CHZBT products, namely, in household distillation units "MAGARICH".

Recently, to lower the net cost, some manufactures have been looking for the opportunities to use the AISI 430 grade which is low carbon chrome and ferrous stainless steel not containing any nickel at all. Despite the manufacturers' promises, items made of this steel grade are exposed to corrosion even being operated indoors with oxidizing reactions on the item surfaces happening in 2-3 weeks already. The specialists from our plant conducted a simple test placing the still made of the 430 grade into a slightly salted solution and left it for a week. Here is what they saw afterwards:

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That is why we recommend to request a certificate confirming the steel grade the distillation stills you're going to purchase are made of.

The distillation stills "MAGARICH" produced by CHZBT are made of the high-quality steel grade AISI 304 ONLY and proved to be excellent products over a long period of time.

Beware of imitation products!