Technology

 
METU-FORM Technology

METU-FORM is an optimized duct system that meets the growing demands of our industry as well as today's environmental protection requirements.
 

  • Laser-welded ducts, welded fittings
  • Formed-on "Parallel" flange (patented) with SRX joining clips
  • Exceeds the air-tightness class D according to DIN EN 12237, class ATC 1 (DIN EN 16798-3)
  • Liquid and oil tight ducts, fittings and connections
  • Smooth, dirt-retardant and easy to clean inner surfaces
  • Parts made from thin sheet metal, easy to transport
  • Easy installation: Allen keys are the only tools you need.
  • The parts have a discrete appearance
  • Available in galvanized steel from 80 to 1000 mm Ø
  • Available in stainless steel V2A  (1.4301 / ASTM 304) from 200 to 1000 mm Ø
  • No ATEX / Ex certifications
  • Many applications
METU-FORM : Three Possible Executions Depending on the Diameters

For the oil-tight applications it is recommended to use the "parallel" system.

d1: from 80 to 200 mm (plain)
d3: from 80 to 200 mm (plain)

Plain System (no flanges), assembly with MUX Overcollars

d1: from 80 to 1000 mm (with Parallel Flanges)
d3: from 80 to 1000 mm (with Parallel Flanges)

Parallel System (without formed-on flanges), assembly with SRX Joining Clips

d1: from 80 to 1000 mm (with parallel flanges)
d3: from 80 to 200 mm (plain, without flanges)

A combination of both systems: plain and parallel.
Assembly of the "plain" system with MUX Overcollars
Assembly of the "parallel" system with SRX Joining Clips

The Parallel System (80 to 1000 mm Ø)

The "parallel" flange is formed directly from the duct itself.
The shape of the formed-on flange is very precise.
The flange is sturdier than a turned-out edge or Vanstone flange.
Its manufacture is relatively complicated and protected through international patents.

Patented Technique

The new patented METU-FORM ® formed-on flange technique, along with laser-welded ducts, make possible the efficient manufacture of straight ducts and fittings with unmatched quality and performances. 

Tightness

Thanks to the formed-on flanges, the number of welded or brazed (MIG) joints is drastically reduced. The assembly through an SRX joining clip fitted with an NBR gasket provides an oil-tight connection. That automatically implies that the duct system is water-tight and a practically zero air-leakage is achieved, thus outperforming the highest tightness class D (DIN EN 12237). Tightness class ATC1. When dismantling the SRX joining clips, we recommend to always replace the gasket.

Easy, Timesaving Assembly

The precisely formed-on parallel flanges, the NBR gasket fitted into the patented SRX joining clips, as well as their innovative one-bolt tightening system, allow an efficient and quick assembly. The parts align themselves automatically.

Continuous Smooth Inner duct Surface

All straight ducts, bends and welded fittings have a smooth, protrusion-free inner surface. This feature translates into energy savings, noise reductions and less dust accumulation. Furthermore, duct-cleaning operations are facilitated.

Stability

The precisely formed-on and sturdy flanges increase the duct’s resistance by positive and negative pressures drastically.

Equipotential Bonding (ESP)

The SRX Joining Clip allows a metal-to-metal connection between the various duct components, and therefore guarantees the equipotential bonding of the system without having to take any additional measures (must always to be verified).

Execution

Since the parallel flange is formed from the duct itself, the longitudinal laser-weld is the unique duct joint. Fittings also have a laser welded joint. The additional radial and other necessary joints for the manufacture of curved fittings are MIG-brazed.

Ø 80 to 160 mm : Height of the formed-on Parallel-Flange ≈ 6 mm
Ø 200 to 450 mm : Height of the formed-on Parallel-Flange ≈ 10 mm
Ø 500 to 1000 mm : Height of the formed-on Parallel-Flange ≈ 15 mm

Pressure Resistances

Positive Pressure: max. +10.000 Pa.
Negative Pressure: max. - 4.000 Pa
A pre-requisite, especially with negative pressures, are undamaged ducts free of any distortions. For higher resistance requirements the ducts are also available, upon request, with aerodynamic strengthening ribs.

Limitations

The parallel flange cannot be created on the building site. If ducts must be shortened on site, telescope fittings must be used.
Ø 180 mm not available
Ø 80 up to 180 mm in V2A not available
CAUTION: The METU-FORM system is not explosion proof (no ATEX / Ex certificates)..

The Plain System (80 to 200 mm Ø)

Ducts and fittings without flanges or turned-out edges.
The ends of the ducts or fittings are plain.
The ducts can be shortened on site and then simply
connected together with the MUX Overcollars.
Available lengths: 0.5 m, 1.0 m, 1.5 m, 2.0 m.

Tightness

The MUX Overcollar, fitted with an NBR gasket and connects around the plain ends of the ducts, provides an oil-tight connection. Being oil-tight (*) also means water-tight and a practically zero air-leakage (ATC1). Such a connection outperforms the highest air-tightness class D (DIN EN 12237).

Easy, Timesaving Assembly

The ends of the ducts to be connected are simply inserted into the MUX Overcollar. The unique Allan screw is then tightened. One advantage of the MUX Overcollars is that slight angle deviations are possible without having to use fittings.  As plain ducts are not fitted with flanges, there is no need to purchase short ducts: standard ducts can simply be cut to the desired lengths and then connected together with the MUX Overcollars.

Continuous Smooth Inner-duct Surfaces

All straight ducts, bends and welded fittings have a smooth, protrusion-free inner surface. This feature translates to energy savings, noise reductions and less dust accumulation. Furthermore, duct-cleaning operations are facilitated.

Equipotential Bonding (ESP)

The thickness and hardness of the NBR gasket does not allow a metal-to-metal contact between the duct sections. A special MUX version fitted with a contact band is available for equipotential bonding purposes (must always to be verified).

Execution

Usually the longitudinal laser-weld is the only duct seam. Fittings also have laser-welded joints. The additional radial and other necessary joints for the manufacture of fittings are MIG-brazed. Ducts and fittings have plain ends. 

Pressure Resistance

Positive Pressure: max. +10.000 Pa.
Negative Pressure: max. - 3.000 Pa.
A pre-requisite, especially with negative pressures, is to have undamaged ducts free of distortions.

Plain version for diameters from 200 to 1000 mm

Larger diameters up to 1000 mm are also available. For such cases the METU-SYSTEM round duct connections must be used. These connections are not liquid- / oil-tight. Please refer to the METU-SYSTEM round duct connections.

Limitations

The alignment of the parts is more difficult to achieve than with the parallel system.
Ø 180 mm not available
Ø 80 up to 180 mm in V2A not available
CAUTION: There are no ATEX / Ex certificates. Not suitabke for ATEX / EX Applications.

Recommendations

For the oil-tight applications it is recommended to use the "parallel" system.

If the diameters d1, d2 and d3 are above 200 mm, only the "Parallel" system can be used.

If the diameters d1, d2 and d3 are below 200 mm, both systems can be used. We recommend sticking with only one system whenever possible.

If you need to install ducts over relatively long distances, the "Parallel" system is easier and faster to install. It also aligns itself automatically, am operation which is more difficult to achieve with the "Plain" system (assembly with MUX Overcollars).

On the other hand, if the diameters are below 200 mm, if the duct sections are short, and if it is difficult to determine the exact lengths beforehand, then the "Plain" system is probably better suited than the "Parallel" one.

Should you have the same situation as described above, but with diameters of 200 mm and above, then the "Parallel" system must be used. The only way to shorten the ducts on site would then be to use telescope fittings.

Should you have any questions or need advice, please do not hesitate to contact us.

Caution

(*) Gasket Useful Life Expectancy

Gasket suppliers cannot give any guarantees regarding their gaskets, and consequently neither can we. These are limitations which do not apply only to our products but to any products involving gaskets. Our METU-FORM duct system is tight as long as the gaskets keep their properties, and these do inevitably change over time. Replacing gaskets whenever necessary (i.e. when leakages appear) is a normal procedure and cannot be seen as a malfunction or a defect.

Suitability

The provided information do not discharge the user from conducting his own tests. Please make sure that the product is suitable for the intended use. As the properties of the gaskets change over time an adequate tightness cannot be guaranteed over the long term. It might be for that reason necessary to replace the gaskets from time to time. The intervals cannot be defined, as they depend on the installation, the operating temperatures, the products and chemicals present in the air-flow, and possibly other parameters.

Translation

In case of discrepancies the German version prevails.

Oil Tightness Tests

METU and the Norms

 

Properties of an ideal air-duct

Are round ducts better?

Diameters

SRX Equipotential Bonding

METU-FORM Welding Methods

Material Thicknesses and Tolerances

Ø: Unless otherwise specified the diameters always refer to the inner diameters of the ducts and fittings.

Sturdy formed-on "parallel" flange created from the duct itself

 

Smooth inner surfaces

 

Air and oil tight (ATC1)

 

The "Parallel" system is better suited for long sections. On this project (IMTECH) the METU-SYSTEM round duct connections (AF, SR) and the METU-FORM ducts (Class ATC1, oil-tight) have been installed next to each other.