Type ARK

Non-return damper, variant ARK

Non-return damper with linkage

Non-return dampers prevent unwanted airflows against the intended airflow direction when the system is not in operation

Air leakage with back pressure to EN 1751, class 4
Maximum differential pressure: 5000 Pa
Blades made of aluminium, casing made of galvanised steel
Available in standard sizes and many intermediate sizes
Variant ARK (with linked blades) for variable volume flows
Variant ARK-1 (with adjustable blade restrictors) for constant volume flows
Installation in horizontal or vertical ducts

Optional equipment and accessories

Installation subframe
Powder coating (RAL or DB)
Stainless steel construction with stainless steel casing; blades made of aluminium
Temperature resistant up to 200 °C with Viton seal

General information

Application

Non-return dampers for the fresh air and exhaust air ducts of ventilation and air conditioning systems
Prevention of unwanted airflows against the intended airflow direction when the system is not in operation
Blades close automatically when the system is shut down
Maximum differential pressure: 5000 Pa

Special features

Robust, maintenance-free construction
Maximum differential pressure: 5000 Pa
Closed blade air leakage with back pressure, in closing direction, to EN 1751, class 4
Damper for negative or positive pressure (air extract or discharge)
Operating temperature 0 to 80 °C
Optional temperature resistant construction for up to 200 °C, with Viton seal
Installation in horizontal or vertical ducts
Maintenance-free DU bearings with Teflon coating, bearing shafts made of stainless steel

Nominal sizes

B: 200, 400, 600, 800, 1000, 1200 mm (intermediate sizes: 201 – 1199 mm, in increments of 1 mm)
H: 345, 675, 1005, 1335, 1665, 1995 mm (intermediate sizes 355 – 505, 685 – 835, 1015 – 1165, 1345 – 1495, 1675 – 1825 mm in increments of 1 mm)
Any combination of B × H

Variants

ARK: Non-return damper with linked blades, preferably for variable volume flows
ARK-1: Non-return damper with adjustable blade restrictors, preferably for constant volume flows

Construction

Galvanised sheet steel, duct connection without flange holes
A2: Stainless steel
G: Duct connection with flange holes

Accessories

Installation subframe for the fast and simple installation of mechanical self-powered dampers

Standards and guidelines

Closed blade air leakage (against the intended airflow direction) to EN 1751, class 4
Casing air leakage to EN 1751, class C

Maintenance

Maintenance-free as construction and materials are not subject to wear
Contamination should be removed as it may lead to corrosion and to increased closed blade air leakage

Description

Variants

ARK: Non-return damper with linked blades, preferably for variable volume flows
ARK-1: Non-return damper with adjustable blade restrictors, preferably for constant volume flows

Accessories

Installation subframe for the fast and simple installation of mechanical self-powered dampers

Standards and guidelines

Closed blade air leakage (against the intended airflow direction) to EN 1751, class 4
Casing air leakage to EN 1751, class C

Nominal sizes

B: 200, 400, 600, 800, 1000, 1200 mm (intermediate sizes: 201 – 1199 mm, in increments of 1 mm)
H: 345, 675, 1005, 1335, 1665, 1995 mm (intermediate sizes 355 – 505, 685 – 835, 1015 – 1165, 1345 – 1495, 1675 – 1825 mm in increments of 1 mm)
Any combination of B × H

Technical information

Function, Technical data, Quick sizing, Specification text, Order code, Related products

Schematic illustration of ARK

① Casing
② Blade
③ Seal
④ Linkage
⑤ Travel stop (angle section)

Non-return dampers open and close automatically. When the system is in operation, the blades open when air flows. The blade opening angle depends on the differential pressure and the volume flow rate; for variant ARK-1 the opening angle is limited by adjustable blade restrictors. When the system is shut down, the blades close due to their weight. They safely prevent air from flowing against the intended airflow direction.

Nominal sizes	200 × 345 – 1200 × 1995 mm
Volume flow rate range	690 – 23,950 l/s or 2484 – 86,220 m³/h at 10 m/s
Total differential pressure (horizontal airflow)	115 Pa at 10 m/s
Total differential pressure (vertical airflow)	45 Pa at 10 m/s
Maximum permissible differential pressure in closing direction	5000 Pa
Operating temperature	0 to 80 °C

ARK, free cross-sectional area [m²]

H	B
H	200	400	600	800	1000	1200
345	0.043	0.097	0.152	0.206	0.26	0.314
675	0.088	0.198	0.309	0.419	0.529	0.639
1005	0.133	0.299	0.466	0.632	0.798	0.964
1335	0.178	0.4	0.622	0.845	1.067	1.289
1665	0.223	0.501	0.779	1.058	1.336	1.614
1995	0.268	0.602	0.936	1.271	1.605	1.94

Intermediate sizes: Interpolate values between widths.

Horizontal airflow

Quick sizing tables provide a good overview of the volume flow rates with an airflow velocity of 10 m/s. Values for intermediate widths can be interpolated.

ARK, maximum volume flow rate

H	B
	200		400		600		800		1000		1200
	l/s	m³/h	l/s	m³/h	l/s	m³/h	l/s	m³/h	l/s	m³/h	l/s	m³/h
345	690	2484	1380	4968	2070	7452	2760	9936	3450	12420	4140	14904
675	1350	4860	2700	9720	4050	14580	5400	19440	6760	24336	8100	29160
1005	2010	7236	4020	14472	6040	21744	8040	28944	10050	36180	12050	43380
1335	2670	9612	5340	19224	8020	28872	10700	38520	13350	48060	16000	57600
1665	3330	11988	6660	23976	10000	36000	13300	47880	16650	59940	20000	72000
1995	3990	14364	7980	28728	11950	43020	15950	57420	19950	71820	23950	86220

Differential pressure Δp_st[Pa]

v [m/s]	Airflow
v [m/s]	horizontal	vertical
2	50	135
4	75	125
6	95	105
8	110	65
10	115	45

Specification text

Rectangular non-return dampers to prevent air from flowing against the intended airflow direction through fresh air and exhaust air ducts of air conditioning systems.
Ready-to-install component which consists of a casing, blades with low-friction bearings, and travel stop and sealing parts.

Special features

Robust, maintenance-free construction
Maximum differential pressure: 5000 Pa
Closed blade air leakage with back pressure, in closing direction, to EN 1751, class 4
Damper for negative or positive pressure (air extract or discharge)
Operating temperature 0 to 80 °C
Optional temperature resistant construction for up to 200 °C, with Viton seal
Installation in horizontal or vertical ducts
Maintenance-free DU bearings with Teflon coating, bearing shafts made of stainless steel

Construction

Galvanised sheet steel, duct connection without flange holes
A2: Stainless steel
G: Duct connection with flange holes

Technical data

Nominal sizes: 200 × 345 to 1200 × 1995 mm
Volume flow rate range: 690 – 23,950 l/s or 2484 – 86,220 m³/h at 10 m/s
Total differential pressure (horizontal airflow): 115 Pa at 10 m/s
Total differential pressure (vertical airflow): 45 Pa at 10 m/s
Maximum differential pressure in closing direction: 5000 Pa
Operating temperature: 0 to 80 °C
Maximum pressure: 5000 Pa

Sizing data

qᵥ [m³/h]
Δp_st [Pa]

Air-regenerated noise

L_WA [dB(A)]

ARK

–

600 × 1005

P1 – RAL …

1 Type
ARK Non-return damper

2 Blade mechanism
No entry required: linked blades
1 Blades with adjustable restrictors

3 Material
No entry required: galvanised steel, with aluminium blades
A2 Stainless steel with aluminium blades

4 Construction
No entry required: duct connection without flange holes
G Duct connection with flange holes

5 Nominal size [mm]
B × H

6 Installation subframe
No entry required: None
ER With (only for construction G)

7 Surface
No entry required: standard construction
P1 powder-coated, specify RAL CLASSIC colour

Gloss level
RAL 9010 50 %
RAL 9006 30 %
All other RAL colours 70 %

Order example: ARK–1–A2/1000×1995/P1–RAL 7001

Blade mechanism	Blades with adjustable restrictors
Material	Stainless steel with aluminium blades
Construction	Without holes
Nominal size	1000 × 1995 mm
Installation subframe	Without
User interface	Powder-coated, RAL 7001, silver

Accessories

Type Installation subframe

Variants, Product details, Installation

Non-return damper, variant ARK

Non-return damper with linkage

ARK

Variant

Non-return damper with linked blades, preferably for variable volume flows

Nominal sizes

B: 200, 400, 600, 800, 1000, 1200 mm (intermediate sizes: 201 – 1199 mm, in increments of 1 mm)
H: 345, 675, 1005, 1335, 1665, 1995 mm (intermediate sizes 355 – 505, 685 – 835, 1015 – 1165, 1345 – 1495, 1675 – 1825 mm in increments of 1 mm)
Any combination of B × H

Parts and characteristics

Ready-to-install non-return damper
Blades with low-friction bearings
Seal
Travel stop (angle section)
Linkage

Construction features

Rectangular casing, material thickness 2 mm
Blades, material thickness 3 mm
Flanges on both sides, suitable for duct connection, with or without flange holes
Linkage for synchronous blade movement
Blades with perimeter seal, pressed against travel stop (angle section) when closed
Blade shafts with maintenance-free plastic bearings

Materials and surfaces

Casing and travel stop (angle section) made of galvanised sheet steel, material no. EN 10346-DX51D+Z140-200
A2 construction: Casing and travel stop (angle section) made of stainless steel, material no. 1.4301
Blades and linkage made of aluminium, material no. AlMg3
Blade holders made of stainless steel, material no. 1.4301
Blade shafts made of stainless steel, material no. 1.4104
Plastic bearing made of PPS
Neoprene seals
P1: Powder-coated, RAL CLASSIC colour
PS: Powder-coated, DB colour

ARK-1

Variant

Non-return damper with adjustable blade restrictors, preferably for constant volume flows

Nominal sizes

B: 200, 400, 600, 800, 1000, 1200 mm (intermediate sizes: 201 – 1199 mm, in increments of 1 mm)
H: 345, 675, 1005, 1335, 1665, 1995 mm (intermediate sizes 355 – 505, 685 – 835, 1015 – 1165, 1345 – 1495, 1675 – 1825 mm in increments of 1 mm)
Any combination of B × H

Parts and characteristics

Ready-to-install non-return damper
Blades with low-friction bearings
Seal
Travel stop (angle section)
Two adjustable restrictors per blade

Construction features

Rectangular casing, material thickness 2 mm
Blades, material thickness 3 mm
Flanges on both sides, suitable for duct connection, with or without flange holes
Restrictors, adjustable from the outside, to limit the opening angle for each blade
Blades can be moved independently of one another
Blades with perimeter seal, pressed against travel stop (angle section) when closed
Blade shafts with maintenance-free plastic bearings

Materials and surfaces

Casing and travel stop (angle section) made of galvanised sheet steel, material no. EN 10346-DX51D+Z140-200
A2 construction: Casing and travel stop (angle section) made of stainless steel, material no. 1.4301
Blades made of aluminium, material no. AlMg3
Blade holders and restrictors made of stainless steel, material no. 1.4301
Blade shafts made of stainless steel, material no. 1.4104
Plastic bearing made of PPS
Neoprene seals
P1: Powder-coated, RAL CLASSIC colour
PS: Powder-coated, DB colour

ARK, standard sizes

B: 200 – 1200 mm, intermediate sizes 201 – 1199 in increments of 1 mm
H: 345 – 1995 mm, intermediate sizes 355 – 505, 685 – 835, 1015 – 1165, 1345 – 1495,
1675 – 1825 mm in increments of 1 mm
The weight for the next larger size applies

Flow cross section to calculate the airflow velocity

A = B × H

Unit of measure for B and H: m

ARK: Standard sizes, dimensions

H	No. of blades	No. of coupling rods
345	1
675	2	1
1005	3	1
1335	4	2
1665	5	2
1995	6	2

ARK: Intermediate sizes, dimensions

H	No. of blades	No. of coupling rods	Y
355 – 505	1	0	5 – 80
685 – 835	2	1	5 – 80
1015 – 1165	3	1	5 – 80
1345 – 1495	4	2	5 – 80
1675 – 1825	5	2	5 – 80

ARK-1: Standard sizes, dimensions

H	No. of blades
345	1
675	2
1005	3
1335	4
1665	5
1995	6

ARK-1: Intermediate sizes, dimensions

H	No. of blades	Y
355 – 505	1	5 – 80
685 – 835	2	5 – 80
1015 – 1165	3	5 – 80
1345 – 1495	4	5 – 80
1675 – 1825	5	5 – 80

ARK, ARK-1, weights [kg]

H	B
H	200	400	600	800	1000	1200
345	8	10	12	15	18	21
675	12	16	19	23	27	32
1005	17	22	26	31	36	41
1335	22	28	33	39	45	51
1665	27	34	40	47	54	61
1995	32	40	47	55	63	71

Flange holes, ARK

① Even number of holes (hole pitch = 250 mm)

② Uneven number of holes (hole pitch = 250 mm)

ARK, ARK-1, ARK2: width, no. of flange holes

H	Number of holes n
200 – 287	1
288 – 537	2
538 – 787	3
788 – 1037	4
1038 – 1200	5

ARK, ARK-1, ARK2: height, no. of flange holes

H	Number of holes n
345 – 461	2
462 – 711	3
712 – 961	4
962 – 1211	5
1212 – 1461	6
1462 – 1711	7
1712 – 1961	8
1962 – 1995	9

Installation into an internal wall, without installation subframe

① Blade movement area must be kept clear

Illustration shows ARK-1

Installation and commissioning

ARK

Installation orientation: Horizontal airflow, any airflow direction; or vertical airflow with airflow from bottom to top
Only for installation in internal spaces

ARK-1

Installation orientation: Horizontal airflow, any airflow direction; or vertical airflow with airflow from bottom to top
Only for installation in internal spaces
Adjusting the restrictors to limit the opening angle for each blade

ARK

ARK