Twin wall systems are the ideal solution for homes where there is no chimney, a flue system is needed for use with a multi-fuel, wood burning or gas appliances. Twin wall pipe is insulated double skinned flue with a double layer of 316 grade stainless steel with a 25 mm installation section of rockwool with a outer layer of 304 grade steel.
Twin wall outer layer
The Twin wall outer layer of the flue can pass within 50mm of any combustible materials, this makes it ideal to install in existing homes, it is also weatherproof and carries the structural load of the flue system.
Rockwall Insulation
High density 25mm rockwall between the layers of the twin wall flue pipe will keep the external flue pipe cool with thermal resistant properties, warm gases then rise up the flue with the reduction of tars on the internal flue that can often cause chimney fires.
Twin wall Inner layer
The 316 grade stainless steel inner layer will withstand coal and wood burning gases from stoves and real fires. When the inner steel flue pipe heats up a strong draft will ensure the waste gases are dispersed up the flue, as gas temperatures change the steel wil contract and expand throughout the stove or fire burn time.
Flue Pipe Advice
When installing twin wall flue systems there should be a limited amount offsets and horizontle turns. If a solid fuel appliance is installed the distance between two 45 degree bends should not be greater than 20% off the height. Manufactures often recomend a increase the flue diameter, a twin wall flue should not be reduced to less than the flue diameter on the stove.
Using a locking band system to connect twin wall lenghts prevents any leakage and seals the flue. For sweeping, inspection hatches are normally found in vitreous enamel pipes or in 135 degree twin wall tee & caps.
Support brackets are recomended every 2m on all flue systems they are available in both fixed and adjustable.
Adapters are used when when using virtreous enamel to twin wall insulated pipe sealing the joint and allowing you to increase the diameter of the flue. It is always recomended you increase the flue diameter, this applies to all types of flue liners, your stove should work more efficiently with thelp from the draw on the chimney flue.
All lengths and offsets connect together using a locking band system which seals the flue and prevents any leakage, no joints should be made in walls or going through floors. Access must be made for sweeping and inspection purposes these are generally found in Vitreous enamel pipes with sweeping hatches or in 135 degree twinwall insulated Tee & Caps.
Internal installation.

External through the wall installation.
