Butter fly Non-Return Damper
Typical Application
Ordering
A range of high integrity dampers has been designed
Quantities, surface finish and other special require-
to meet the requirements of the nuclear industry,
ments to be stated separately.
where low case leakage, corrosion resistance and
mechanical integrity are of prime importance. They
Duct Dia 300Dia
Type BNRD
are used to prevent backflow whilst allowing airflow
through mixed flow or axial fan outlets. They are not
Case Depth Variable
Material 316L
intended for isolation purposes.
Case Thickness 3.0
The following design features have been included:
Type Wozair:
Butterfly Non Return Damper
Gravity operation
Continuously welded construction
Dual blade pivotal around central axis
Case Material:
Low casing leakage
Stainless Steel
1.4301
= 304
(SS304)
Low airflow resistance
(SS304L) = 304L
Low Carbon
1.4307
Excellent corrosion resistance
Low Carbon
1.4404
(SS316L) = 316L
Casing
Mild Steel Sheet
Rolled casing manufactured from 2mm minimum
Galvanised after Manufacture = GAM
thick material, with welded seam, length over
flanges minimum 100mm. Welded flanges 25 x
Case Thickness: 2.0mm upwards
3mm thick drilled to standard nuclear spec. pattern.
Note: The damper depth is a function of the case
Nominal
Clear inside duct dimensions
diameter and therefore a variable.
Duct Size:
Ranging from 300 to
1000mmDia
Blades
Order Code Example:
A pair of semi-circular blades pivot on an individual
BNRD/316L/3.0/300Dia
shaft to form a 2mm thick circular butterfly blade.
Galvanised material option available.
Control and Operation
Blades open under fan air pressure and close by
gravity or backflow through the duct system
Air Flow
Front Elevation
Side Elevation