PF Instructions

 

To make sure the flange fits

Checking the duct inner diameter

To control the inner duct-Ø please refer to the MRF measuring band instructions.

The circumference / diameters of the PF circular flanges cannot be modified. For this reason, the PF circular flanges cannot always be installed around the ends of fittings. Should you wish to use the PF flanges on fittings, it is recommended that you conduct a few tests with PF samples first.

Tightness

Before inserting the flange into the duct apply an adequate sealant into the groove of the flange along its entire circumference.

Air-tightness class C
Air-tightness class C

Installed properly the air-tightness classes C and even D according to DIN EN 12237 can be reached.

Fitting the Flange

METU symbol of a duct with a longitudinal seam
Deformed longitudinal seam or fold

The seam on longitudinal seam ducts might deform when inserting the flange.

Spot-welded longitudinal air-duct seam
Secured fold

We therefore recommend to spot weld or rivet the seam in the vicinity of the duct ends before inserting the flange.    

The fold too high in relation to the flange
Grind down the spiro seam a little

If the seam is too high (A) preventing the flange from being inserted all the way in, grind it down (B).

Insert the flange into the duct. A rubber hammer might be necessary.

Fastening Methods

METU symbol of a rivet
Swaging

Fastening in the duct through blind-rivets and swaging (reduces the projections inside the duct).

METU symbol of the self drilling screws

Screws are less recommended, as they protrude inside the duct, hindering the air-flow and the cleaning operations, and could be the cause of leakages.

Symbol of spot welding

Spot welding only possible when the flange and duct are an exact fit (low tolerances).

PF made of Stainless Steel (V2A)

Cracks can appear on the stainless steel versions. They are unavoidable and consequently no reason for a claim.

For further instructions please refer to the SS Joining Clips section.