The SLIPSIL® Sealing Plug system is the quick, reliable choice for permanently sealing unused or spare ducts, sleeves, and conduits. Designed for straightforward installation without special tools or frames, SLIPSIL® Sealing Plugs provide certified protection against fire, water and gas ingress, ensuring every opening in your infrastructure is safe and compliant.

Seal smarter with SLIPSIL®
Premium protection in every environment. Seal out risk. Seal in confidence. From power plants and substations to telecoms and transport hubs, SLIPSIL® Sealing Plugs are trusted worldwide for their ease of use and long-term durability. Their flexible rubber construction ensures a tight, reliable seal that adjusts to variations in duct size, while their maintenance-free design makes them a cost-effective solution for decades to come.


SLIPSIL® Sealing Plugs
Key Benefits
- Up to 2 hours fire resistance – tested and certified.
- Watertight and gastight – pressure-tested for long-term reliability.
- Fast installation – no frames or special tools required.
- Versatile sizing – wide range of plug diameters for any duct size.
- Maintenance-free – 50+ year service life, age-tested performance.
Designed For
- Power generation and utility networks
- Industrial and civil infrastructure
- Telecoms and fibre optic rollouts
- Transportation hubs
- Commercial construction
Useful Information
The installation advantage
With no frame or mastic required, SLIPSIL Sealing Plugs can be installed in minutes. Their tapered, elastic design allows for simple hand-fitting into ducts, instantly delivering a secure, certified seal. This makes them the ideal solution for fast-paced projects where reliability and efficiency cannot be compromised.

“CSD Technical Services delivered the water, and gastight sealing works to a high standard across our control room and DNO substation. Their support contributed effectively to our wider climate action plan, including the installation of a new solar farm and battery storage system. We were very satisfied with the work and will be considering CSD for future projects.”
CSD client
Morrison Data Services