CAV controllers Type RN-Ex
Circular, mechanical self-powered volume flow controllers for the control of supply air or extract air in constant air volume systems, approved and certified for potentially explosive atmospheres (ATEX)
Optional equipment and accessories
Application
Special features
Classification
According to type examination certificate TUEV 05 ATEX 7159 X
Nominal sizes
Variants
Construction
Parts and characteristics
Accessories
Useful additions
Construction features
Spigot with insert bead for lip seal; (except RN-Ex-P1/80 not possible with insert bead/lip seal)
Materials and surfaces
Galvanised sheet steel constructionStandards and guidelines
Maintenance
Functional description
The volume flow controller is a mechanical self-powered unit and works without external power supply. A damper blade with low-friction bearings is adjusted by aerodynamic forces such that the set volume flow rate is maintained within the differential pressure range.
The aerodynamic forces of the airflow create a closing torque on the damper blade. The bellows extends and increases this force while at the same time acting as an oscillation damper. The closing force is countered by a leaf spring that unrolls over a cam plate. The shape of the cam plate is such that a change in the differential pressure leads to an adjustment of the damper blade in a way that the volume flow rate is maintained almost exactly.
Efficient commissioning
The volume flow rate setpoint value can be set quickly and easily using the pointer on the external scale; no measurements are required.
The advantage over flow adjustment dampers is that there is no need for repeat measurements or adjustments by an air conditioning engineer. Should the system pressure change, e.g. by opening or closing of duct sections, the flow rates in the entire system will also change if flow adjustment dampers are used; however, this is not the case with mechanical self-powered volume flow controllers A mechanical self-powered controller reacts immediately and adjusts the damper blade such that the set constant volume flow rate is maintained.
Volume flow rate ranges
The minimum differential pressure of CAV controllers is an important factor in designing the ductwork and in rating the fan including speed control.
Sufficient duct pressure must be ensured for all operating conditions and for all control units. The measurement points for fan speed control must be selected accordingly.
Nominal sizes | 80 – 400 mm |
Volume flow rate range | 11 – 1400 l/s or 40 – 5040 m³/h |
Volume flow rate control range | Approx. 25 to 100 % of the nominal volume flow rate |
Scale accuracy | ± 4 % |
Minimum differential pressure | 50 Pa (nominal size 80: 100 Pa) |
Maximum differential pressure | 1000 Pa |
Operating temperature | 10 – 50 °C |
Circular volume flow controllers for constant air volume systems in potentially explosive atmospheres, mechanical self-powered, without external power supply, suitable for supply or extract air, available in 8 nominal sizes.
Ready-to-commission unit consists of the casing containing a damper blade with low-friction bearings, bellows, external cam plate with leaf spring, and parts for equipotential bonding and for protection in potentially explosive atmospheres.
Volume flow controllers are factory set to a reference volume flow rate (customers can set the required volume flow rate on site).
Spigot with groove for lip seal, suitable for connecting ducts according to EN 1506 or EN 13180.
Casing air leakage to EN 1751, class C.
Special features
Materials and surfaces
Galvanised sheet steel construction
Powder-coated construction (P1)
Stainless steel construction (A2)
Variant with acoustic cladding (-D)
Mineral wool
Construction
Technical data
Sizing data
Air-regenerated noise
Case-radiated noise
This specification text describes the general properties of the product. Texts for variants can be generated with our Easy Product Finder design programme.
5 Accessories
No entry: without accessories
D2 Double lip seal both ends
Order example: RN-Ex/160/D2
Nominal size | 160 |
Material | Galvanised sheet steel |
Accessories | Lip seals on both ends |
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Contact
We are here for you
Please specify your message and type of request
Tel.: +49 (0)2845 / 202-0 | Fax: +49 (0)2845/202-265
Contact
Thank you for your message!
Your message is send and will be processed shortly.
Our department for Service-Requests will contact you asap.
For general question regarding products or services you can also call:
Tel.: +49 (0)2845 / 202-0 | Fax: +49 (0)2845/202-265
