CSD NOFIRNO Duct Seals – Multi Cable & Pipe Transit Sealing

CSD NOFIRNO Duct Seals - Multi Cable & Pipe Transit Sealing

CSD NOFIRNO Duct Seals – Multi Cable & Pipe Transit Sealing

CSD NOFIRNO Duct Seal System

Watertight, Gastight & Fire Protection & Sealing for Cables & Duct Entries

CSD NOFIRNO duct seals is a multi-cable and pipe transit sealing system designed specifically for cable duct seals and building entries providing an effective and simple solution protecting against flood water and gas ingress.

NOFIRNO duct seals consist of rubber multi sleeves which are in bonded strips of 10 sleeves and a high quality silicone based sealant which are quicker and easier to install than the CSD standard RISE duct seals.

The bonded sleeves can be easily torn off for filling smaller gaps and using cutting tool sleeves can be quickly slit to allow fitting around cables ensuring cable separation – NOFIRNO duct seals are also used to pack the free space, providing a backing for the application of the cable sealant.

Completing the seal with a 20mm layer of NOFIRNO sealant will provide a technically advanced and high performance duct seal. View the complete range of CSD Sealing Systems to protect against damage caused by water ingress, gas spread or fire/flame to cables and ducts.

Thorne & Derrick provide competitive prices and fast delivery from stock for the complete range of CSD duct seals – this includes CSD RISE, RISE RAPID, NOFIRNO, ACTIFOAM and SLIPSIL products.


Features & Benefits 

  • DSEAR compliant duct seals – congested cable ducts sealed from risk of fire spread and gas explosion
  • Hazardous area cable sealing – ATEX compliant duct seals for Zone 1 & Zone 2 potentially explosive atmospheres
  • Compatible with XLPE, EPR and most cable sheaths common to LV 11kV 33kV 66kV 132kV power cable
  • WIMES approved – Water Industry Mechanical & Electrical Specification accepted
  • 2 component sealing  – i) FIWA sealant ii) rubber insert sleeves
  • Age testing documents no deterioration in cable duct sealing performance for more than 50 years
  • Trefoil cable sealing of single core LV 11kV 33kV power cables into substations
  • Resistant to corrosive gas including methane, hydrogen sulphide and chlorine
  • No transit frame required – accommodates all cable configurations and opening (round/rectangle)
  • Re-enterable duct seal for adding, removing and replacing LV, MV & HV cables during cable upgrades
  • Quick and easy to install duct sealing system
  • Substation flood protection and protects against harmful gas ingress through unsealed ducts
  • Cost effective protection of cable ducts against water, gas and fire
  • Resistant to submersion in petrol, diesel and synthetic transmission oils
  • Substation flood protection – the NOFIRNO duct seal is tested from the front and back of the cable seal
  • NOFIRNO can be used to seal ducts in running water conditions when using CSD SLIPSIL Waterstop or Aquastop
  • Prevents rodent attack

Gas and Watertight Duct Seals

The elasticity and high bonding strength of NOFIRNO sealant offers a flexible seal, which resists movement, shock and vibration, as well as high pressure, preventing the migration of dangerous gases and provide flood protection for more than 50 years. The system has been independently tested and proven to provide a pressure resistant seal up to 2.5 bar.

NOFIRNO duct seals are available as standard for a broad range of duct sizes from 50mm up to 300mm and can also be used to suit any sized opening upon request.

Standard CSD NOFIRNO Duct Seal Sizes

Nofirno Duct Seal Certification & Testing

RequirementTest DetailCable Sealing Certification
Water and gas-tight protection. Pressure tested from front and back of seal. Provides flood protection and ensures compliance with DSEAR and ATEX regulationsProvides 2.5 bar pressure rating from front of seal and 2 bar from the back of the seal. Nofirno system is tested and certified up to 7 bar.ABS witnessed test, Report Number: RO-2497866-A
Tested to prove no deterioration in performance for more than 50 yearsAge tested to 50 yearsTNO Institute of Industrial Technology
Resistant to Hydrogen Sulphide, Chlorine and Methane and many other gases and liquidsTested to ensure no breakdown of sealant layer following exposure to dangerous and potentially corrosive gases.TNO Institute of Industrial Technology
Prevents rodent ingressProven to show no deterioration in performance of seal following exposure to rodents. Comparison test with mineral wool (50% deterioration during test period) and expanding foam (70% deterioration during test period).HC Electric Laboratory. Test Report 022/15
Resistant to submersion in fuel oils including petrol, diesel and synthetic transmission oilsTested to ensure no breakdown of sealant layer following contact or submersion in fuel oils to ensure suitability for petrol forecourts, bund walls and petrochemical plants.TNO Institute of Industrial Technology
Allows movement of cables and pipes without damaging services or penetration sealDynamic cycling through 100,000 cycles without deterioration. Stretch factor 140% continuous 195% maximum. Tested to prove continued protection following short circuit event.TNO Institute of Industrial Technology
Suitable for outside use even in harsh weather or when exposed to direct sunlightTested to show no deterioration in performance in temperatures -40°C to +120°C. Tested to ISO4892 to prove no deterioration in performance when exposed to UV radiation.TNO Institute of Industrial Technology


Tools Required

  • High Ratio Sealant Gun
  • Long Nose Pliers
  • Approved Degreasing Wipes
  • Cellulose Sponges
  • Wooden Depth Gauge (Marked at 20mm)
  • Longer Cartridge Nozzles & Angle Connectors
  • Disposable Nitrile Gloves
  • Water Spray
  • Head Torch
  • Cartridge Cutter
  • Duct Seal Installation Kits Available


Installation Instructions

CSD NOFIRNO Duct Seals - Installation Instructions 1

Step 1 – Ensure the duct opening is clear, remove any debris which may interfere with the installation of the NOFIRNO Duct Seal. Carefully cutting off any cable ties will help separate the cables. The duct should also be dry. For running water applications contact CSD.

Step 2 – Using an approved degreasing cleaner, thoroughly clean all surfaces where sealant will be applied. All dirt, cement, dust or oil must be removed from the inside edge of the duct or building entry and the outside of any cable or service pipe. Several wipes may be needed. The NOFIRNO sealant will not bond to any surface that is not clean and dry.

Step 3 – To ensure a cable separation for installations with smaller cables, use the sleeve cutting tool to slit a quantity of the NOFIRNO sleeves. This should be about equal to the quantity of cables in the duct.

Step 4 – Place a split sleeve around each of the cables in the duct and then push the multi sleeves into the duct. For larger or single cables, this is not necassary. Simply ensure the multi sleeves provide separation between cables and between the duct and cables.

CSD NOFIRNO Duct Seals - Installation Instructions 2

Step 5 – Fill the remaining free space with spare NOFIRNO multi sleeves.

Step 6 – Any small gaps should be filled with smaller sized 18/12 NOFIRNO multi sleeves. Multi sleeves can be easily separated in to smaller quantities. It is important to ensure multi sleeves are tightly packed into the duct to create a solid base for the application of the sealant.

Step 7 – Push all of the multi sleeves into the duct.

Step 8 – Push sleeves into the duct to depth of 20mm, allowing for the application of the NOFIRNO sealant layer.

CSD NOFIRNO Duct Seals - Installation Instructions 3

Step 9 – Adjustments can be made to the multi sleeves using a pair of long nosed pliers. Allowing the correct 20mm depth will ensure a suitable layer of sealant is applied and a good seal is maintained.

Step 10 – Attach the nozzle to the NOFIRNO sealant cartridge and snip the nozzle at an angle, this will help installation. For awkward applications longer nozzles and angled applicators are available. To ensure a good bond is made, before adding the NOFIRNO sealant, clean the duct and cables again using the approved degreaser.

Step 11 – Using a specialist high ratio caulking gun, apply the NOFIRNO sealant to the least accessible areas, (usually around cables). Apply sealant over sleeves, allowing to fill out to the required 20mm depth; a slight overfill is needed. Use a torch to check for gaps in sealant & apply more sealant if required.

Step 12 – When working with the NOFIRNO sealant we recommend the use of disposable nitrile gloves. Using the water spray dampen the cellulose sponge. This is done to stop the sealant from sticking to the sponge whilst working with it.

CSD NOFIRNO Duct Seals - Installation Instructions 4

Step 13 – Using a dabbing motion, firmly pat down the NOFIRNO sealant, ensuring the sealant makes good contact with both cable and the duct wall. For installation in vertical ducts the sealant should stand just proud of the duct; allowing any water to run off the surface without pooling.

Step 14 – Use the water spray to wet your gloves, this will ensure the sealant does not stick to the gloves.

Step 15 – The surface of the NOFIRNO sealant should then be finished off by hand. Ensure a good smooth finish is obtained by the use of a fast skimming motion. Make sure there is a good seal around all of the cables, paying particular attention between the cables.

Step 16 – Take a final check with a torch to ensure sufficient sealant has been applied and the duct is properly sealed. If there are any areas that do not seem sufficiently sealed add more NOFIRNO sealant in this area and smooth off as before. Clean any excess sealant from the edge of the duct and cables.

CSD NOFIRNO Duct Seals - Installation Instructions 5

Step 17 – The completed NOFIRNO Duct Seal will provide a 4 bar (58 psi) water tight and 1.0 bar (15 psi) gas tight rated seal. The NOFIRNO system is proven to provide maintenance free protection for a period in excess of 50 years.

CSD NOFIRNO Duct Seals - Multi Cable & Pipe Transit Sealing - Installation Layout

CSD NOFIRNO Duct Seals – Installation Layout

  • ABS – 2.5 bar pressue test front of seal
  • ABS – 2.5 bar pressure test back of seal
  • BV – 4 bar pressure test front of seal
  • TNO Efectis Laboratory – Age Tested to prove sealing performance for 50 years with no deterioration in performance
  • TNO Efectis Laboratory – Resistance to Hydrogen Sulphide, Chlorine and Methane
  • HC-Electric Laboratory – Resistance to rodent ingress
  • TNO Efectis Laboratory – Submersion test in petrol and diesel oils
  • TNO Efectis Laboratory – Resistance to salt laden atmospheres and solar radiation
  • Qinetiq – Test for resistance to shock and vibration
CSD NOFIRNO Duct Seals - Multi Cable & Pipe Transit Sealing

Sealing Cable Ducts (Water Tight & Gas Tight)

Data Sheets