A tube in which combustion gases from a combustion appliance are vented out of the appliance to the outdoors.
A tube in which combustion gases from a combustion appliance are vented out of the appliance to the outdoors.
An uninterrupted safety pipe which allows air or expansion of water within a hot water system to escape to atmosphere - normally positioned over a tank/cistern so that any water is discharged into it.
A vertical pipe of relatively small dimensions which protrudes through a roof to provide for the ventilation of gasses. 
An uninterrupted safety pipe which allows air or expansion of water within a hot water system to escape to atmosphere.
A tube in which combustion gases from a combustion appliance are vented out of the appliance to the outdoors.