MD3 Duct Sealing System

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Duct sealing systems MD3 have been developed to an provide effective and simple solution for Gas and Watertight sealing of cables / pipes in ducts or bore holes.

This duct sealing system is extremely flexible and can be installed in ducts vertically and horizontaly.

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Filoform expanding resin 2234

Filoform duct sealing systems have been developed to provide an effective gas and watertight seal of underground cable penetrations. When installing our duct sealing system MD3, you will protect valuables from damage which is caused by gas and water leaks.

Filoform duct seals type MD are based on a specially formulated two-component expanding polyurethane resin. The polyurethane sealant is packed in a transparent plastic bag with a screw ring. In this plastic bag, the two components are separated by a clamping profile. After removal of the clamping profile, the two components are simply mixed together for 30 seconds. The package is now ready for use and can be easily opened with the use of the screw nipple.

After pouring the resin in the duct, the resin starts expanding by forming CO². During the expansion the polyurethane filling material penetrates all areas inside the duct, thus sealing all openings regardless of the shape of the duct or borehole. After this the hardening process starts. The Filoform two component filler provides not only a 100% gas and watertight seal but also offers excellent mechanical strength.

The MD3 system is suitable in situations where more than one cable or pipe is in the duct. The opening of the duct does not need to be completely round.


  • Gas- and watertight 1,0 bar
  • Radon proof
  • After mixing the polyurethane sealant it will expand and cures/hardens with a high density and a closed cell structure
  • Can be used in any shaped or sized duct up to 200mm
  • Easy and quick installation
  • One complete kit for sealing of one duct
  • Seals all known materials: PVC & PE sheeted cables, PILC cables, (HD)PE pipes, PE drink water conduits
  • High mechanical strength, resists ground movement, shocks and vibrations
  • Also suitable for renovation works
  • No architectural measures necessary
  • Used by various utility companies as well as contractors
  • Over 25 years of operational experience
Properties Unit Value
Start time expansion seconds > 95
End time expansion minutes 15
Compressive strength N / cm² > 60
Gas and water tightness 1,0bar 30 days no leakage
Density 10m water column 30 days no leakage
Volume consistency cube 10 x 10cm no change
temperature Cycles, -20°C tot +40°C 10 consecutive cycles no leakage
Vibration test 10 Hz/amplitude 3mm 240 hours no leakage
axial tensile force diameter x 10 N no leakage
Resistance to bending cables 45° in 2 directions >250mm no leakage
Expansion polyurethane foam in pipe cm < 40
Temperature resistance °C +120
Chemical resistance    
0,1N Na₂SO₄ 30 days no degradation
0,1N NaCl 30 days no degradation
0,1N H₂SO₄ 30 days no degradation
0,1N NaOH 30 days no degradation
Diesel 30 days no degradation
Gasonline 30 days no degradation
Molds   good
Radon gas   no transit
Rodents   good
Shelf life months minimal 30
More Information
More information

Download: Material Safety Data Sheet (MSDS)

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Grouped product items
Sku Product Name Duct diameter min.-max. (mm) Maximum cable or pipe diameter in the duct (mm)

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Order unit
82525 MD3 25mm duct sealing set for protection sleeves Ø 25 max. Ø 8 max. Order unit per piece
82550 MD3 50mm duct sealing set for protection sleeves Ø 50 max. Ø 20 max. Order unit per piece
82575 MD3 75mm duct sealing set for protection sleeves Ø 75 max. Ø 40 max. Order unit per piece
80295 MD3 110mm duct sealing set for protection sleeves Ø 110 max. Ø 80 max. Order unit per piece
80296 MD3 160mm duct sealing set for protection sleeves Ø 160 max. Ø 130 max. Order unit per piece
802973 MD3 200mm duct sealing set for protection sleeves Ø 200 max. Ø 160 max. Order unit per piece
802978 MD3 250mm duct sealing set for protection sleeves Ø 250 max. Ø 220 max. Order unit per piece