Nordfab Europe: Ducting General Specifications

Manufacturing and Product Specifications


Nordfab’s laser welded seam Quick-Fit® Ducting System has been used in many different industrial applications, and under various negative static pressures. 

Structural Integrity & Leakage

All fit-together ducting systems allow for some degree of leakage where they are joined. QF® ducting is no exception and is not sold as an airtight system. 

In comparison to other ducting typically used in fit-together / clip-together systems, Nordfab’s QF duct pipe has fully welded, leak-tight laser or plasma welded seams. Spiral and other ducting with lockform seams are not fully welded at the pipe seams and can be expected to have higher leakage rates than QF.
Application of sealants to the individual rolled ends can also enhance the tightness of the system. However, the QF system is sold as a quick way of installing and modifying ductwork while at the same time retaining the usability of each component. In short, QF is designed with the capability to be taken apart, re-assembled, stored or moved. Completely eliminating the possibility for leakage jeopardizes the inherent benefits of the duct.
Our pipe comes in 1,5m lengths with a rolled lip on each end, thus providing reinforcement every 1,5m, which presents a sound structural design that should be as strong or stronger than any pipe in its class according to SMACNA guidelines and regulations.

Manufacturing Profile

Nordfab Europe manufactures Quick-Fit Ducting in Assens Mariager, Denmark. Nordfab QF duct is a clip-together design using a rolled edge design with a single lever clip. The ducting and clips are constructed from similar materials. 

All clips contain a standard gasket made of Nitrile which is suitable for most applications, including oil mist, as long as high temperatures are not an issue. Silicone and ePTFE gasket options are available for higher temperature applications. 

Nordfab Quick-Fit Ducting is available in sizes from 80mmto 710mm diameter.

Engineering Specification

Ducting shall consist of the following:

a. Galvanised steel: DX51D with Z275 Coating

i. Recommended max. service temperature is 200° C. At temperatures ranging between 200° C and 250° C, the zinc-iron alloy layers in galvanised steel will continue to provide a high level of protection from corrosion. However, there may be some peeling, changes in mechanical properties, and reduction in the corrosion protection. 

b. 304SS: Finish meets EN 1.4307 Austenitic

i. Temp rating is 550° C

Ducting manufacturing techniques:

a. Diameters 80mm- 400mm QF Duct, Slip Duct, and collars attached to other components will have one or both ends die formed-rolled to provide a uniform edge around the circumference of the rolled end. The duct and sleeves shall have the longitudinal seam laser welded to allow for a tighter slip joint and reduce system pressure losses. Pipe lengths using laser welded seams will not exceed a nominal 1,5m length. 
The rolled end is used for clamping components together as well as offering reinforcement. Rolled edges provide structural support at 1,5m intervals or less and can be interpreted as a stiffener. 
A Slip Duct is used for adjustment during the install process. Duct is cut to appropriate length and the Slip Duct secures the Duct for install.

b. QF Duct and other QF components larger than 710mm shall utilize a flat flange attached loosely and retained in place using a vanstone lip. The flanged pipe shall have a solid welded seam and not exceed nominal 1,5m length. The flanges provide structural support at 1,5m intervals or less and are considered as stiffeners.

c. Components which will be air direction sensitive will have an arrow label attached showing the proper flow direction.

Clamping rolled edged duct:

a. QF Clips shall be constructed with an over-center, spring-lever action for quick connecting of two pieces of ducting. A retaining pin shall be inserted in the handle and an eyelet on the clip as a safety feature to ensure the handle does not prematurely come undone.

b. When closing the clip, the internal seal shall be compressed in such a manner as to cover both rolled beads for optimum sealing capacity in a full 360° pattern.

For individual product specifications, see our Products pages - search for the product of interest and click on the pdf under the Resources section on that product page - or download the technical data sheet  here.
NOTE: Manufacturing specifications are subject to change as we update our equipment and processes. Please contact Nordfab for additional information.


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Kontakta Nordfab Europe

+45 86 47 11 00 - [email protected]

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