Silvacore is created on a German-made machine imported to the UK. Only two brands are made on the machine and one of the two brands is Silvacore. I have Silvacore in my chimney (Julian Patrick, author of The Stovefitter's Manual).
A flue liner is not a product you want to fail within just a few years. Silvacore is designed for professional trade-fitters desiring a premium product for chimney lining.
Silvacore chimney liner is created from TWO compressed stainless-steel layers and this unique laminate stays smooth when the product is passed around chimney bends (with a lesser-quality liner the laminate usually comes apart when dragged through bends - allowing acids from soot deposits to enter and later cause corrosion).
904 and 316 are grades of stainless steel. If you are a heavy user of coal/smokeless fuel then one would be advised to ensure that, as a minimum, the inside layer of your liner is 904 grade.
Silvacore is available in three levels of quality:
316 (15-year guarantee): suitable for non-eco-design stoves, wood-only fuel use, light use. This liner has an inner core of 316 stainless.
904 (30-year guarantee): suitable for all stoves and all fuels (including eco-design stoves), light to medium use. This liner has an inner core of 904 grade stainless.
W3G* (Lifetime Guarantee): suitable for all stoves and all fuels (including eco-design stoves), heavy use and for those who really do not wish to replace a chimney liner for as long a period as possible. This revolutionary product has a treated double-layer of 904 grade stainless.
Unlike most other brands (where the layers separate on bends) Silvacore can be fitted any way up in the chimney.
TOP TIP: Slumbering a stove or "banking it up" overnight can shorten the life of the liner. This is because the bad stuff in the gases is not burned off and condenses within the liner. Slumbering is bad for liner, cowl and the environment. Don't do it. Do not mix wood with coal or smokeless fuel (moisture in wood reacts and creates Sulphuric acid). If you insist on slumbering you must choose W3G.
*As is the norm with chimney-liner manufacturers, chimney liner CANNOT be returned as this is a customised cut-to-length item direct from manufacturer on your behalf. So please measure and choose carefully.