NVS Limited

Twin Wall Stove Pipe, Gas B-Vent

Twin wall gas heating system designed for cost-effective venting of residential and small commercial atmospheric gas appliances with input up to 60kw. It is suitable for both internal and external use, either as a complete system or in combination with masonry, i.e. flue blocks or brick chimneys.

Note that BS 5440-1 requires the use of a stainless steel insulated flue on external runs exceeding 3 metres. K Vent fulfills this requirement and is fully interchangeable with the B Vent range.

Our Gas B-Vent components are available in the following circumference sizes: 100mm, 125mm and 150mm.

Click on the images below to view more on our Gas B-Vent components.

Gas appliances up to 60kW input; 75 - 150mm internal diameter; Flue boxes and chimney system to fit gas fires in rooms without a conventional chimney; Residential and small commercial applications. Twist-lock bayonet jointing system. No locking bands required. Aluminium inner liner and aluzink outer case which can be painted if required. 12.5 mm air gap between case and liner keep case temperature low. 0-90° adjustable bend. When joint is made, the liner covers the jointing collar, shielding it and permitting easy drain-down of any moisture in the flue. B Vent is available in 100, 125 and 150mm internal diameters. The flue size must be as recommended by the appliance manufacturer and must not be reduced, and never smaller than the appliance spigot. This information is provided as a guide only, and for exact flue sizing recommendations, refer to appliance manufacturer's installation instructions and design guide.

Gas B-Vent Installation Gas B-Vent Installation

Flue terminations for gas in domestic situations are governed by BS5440-1 Section 4.2. Adjacent taller structures may require increased height. The minimum flue projection through the roof is 600mm to the underside of the terminal.

Flue routing. Systems should be vertical as far as possible for most efficient evacuation and should not exceed 45° from the vertical,otherwise resistance to flue gas flow will result. Bends should be kept to a minimum and a vertical rise of 600mm minimum should be allowed for immediately above the appliance.

As a general rule, the vertical distance (A) between the appliance and the flue terminal should always be at least twice the horizontal distance (B) between the appliance and the terminal.

The B Vent range includes 0° - 90° fully adjustable bends which can be used where the flue system needs to be offset e.g. to avoid trusses and terminate to a ridge terminal. These bends can be rotated 360° after the angle has been set to achieve the correct direction of flue parts.

New Vent Solutions offers a massive range of chimney liners, chimney systems, stove pipes, chimney cowls, flashings and accessories. If you need to chat, please call the Chimney Flue Store on 0141 336 7742.

Read more about B-Vent Installation here.

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