The chimney is one of the most important parts of the heating system of a private house and must initially be done correctly from high-quality materials. At the moment, the best-selling chimney systems are stainless steel systems, both single-wall, embedded in the walls of the house, and sandwich chimneys.
When the question of purchasing such components arises, it is really difficult for the consumer to figure it out, because the market is oversaturated with rubbish in the literal sense of the word! Each manufacturer praises his product, there are a lot of paid positive reviews on the Internet, everyone has no shortcomings or not so serious, but there are a lot of advantages... how to be
In my hands are two stainless steel pipes, one of which is dazzlingly shiny, and the other is almost matte and no matter how polished it will never acquire such a gloss...
I explain ...
The one that glitters is made of general purpose ferritic-chromium steel, here it is:
Excellent steel, but not for chimneys! AISI 430 is one of the cheapest "stainless steel" materials, corrodes quickly even when installed indoors. Despite the fact that the steel thickness of this pipe is 0.8 mm, its service life is completely short even when used gas boiler will be about 5-7 years, and if the boiler is on solid fuel, the service life will be reduced to 3-5 years old.
This steel has low resistance to heat and does not work well in aggressive environments, because combustion products have a chemical effect on the walls. But what, then, is the second pipe?
The second pipe has a steel thickness of only 0.5 mm, but will last 7-10 times longer than a shiny one ...
Why is that? After all, from childhood we are accustomed to the fact that the thicker, the more reliable. For a chimney, the main parameter is not the thickness of the steel, but its composition and chemical properties!
The second pipe is made of AISI 304 steel, a Russian analogue of 08X18H10.The operating temperature is + 600 ° C, it easily removes condensate and is resistant to all acids even in high concentrations that are released during the combustion of fuel (even firewood, even coal, even gas).
And this steel grade is not the only good steel with a long service life!
The basic rule when choosing a chimney is as follows: if you need a chimney that will not have to be redone after 5 years, then purchase steel of the three hundred AISI series, it provides excellent temperature performance operation and acid resistance, because the steel of this series is a heat-resistant austenitic stainless steel, and not the ferritic type AISI 430 and 439, sold in every super-hyper-mega building market :-)
Austenitic stainless steel of the three hundredth series for chimneys always has a matte shade (not so shiny) and starts with a three: AISI 321, AISI 316, AISI 310, AISI 304.
Steel AISI 3xx:
AISI 310 - refractory steel with a working temperature up to + 1100 ° C. It has excellent oxidation resistance and is used in fireplaces and solid fuel stoves.
AISI 304 - working temperature up to + 600 ° С, practically not subject to corrosion, acid-resistant. It is used in chimneys for gas boilers.
AISI 316 - modified AISI 304. does not corrode at all, operating temperature is + 700 ° С. Suitable for both gas boilers and solid fuel boilers.
AISI 321 - widespread high-alloy steel with operating temperatures up to+ 800 ° C, used in fireplaces and stoves for solid fuels.
On my own I recommend paying attention to these steels. Yes, they are not sold everywhere, but it is better to spend time and overpay, for this you will get quality and avoid altering the chimney for the next 30-50 years!
Thanks!