Filoform FiloSeal+HD Reenterable LV HV Power Cable Duct Seal System

By Chris Dodds on 14th July, 2016

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Cable Duct Seals

Expanding spray foam violates engineering "good practice" in the power utility industry and is banned by UK DNO's - foam degrades under water pressure and contact leading to flooded substations.  

New from Filoform is the FiloSeal+HD re-enterable duct sealing system which provides a strong support system using hexagonal tubes which build up like a honeycomb structure to prevent water ingress and gas migration through cable ducts - this includes sealing LV-HV (11kV-33kV) power cable ducts and Triplex cables entering high voltage substations.

The FiloSeal+HD is suitable for any cable configuration (single or multiple) contained within one duct and also allows for easy re-entry of the duct seal to add or remove cables or pipes as required. 

Filoform FiloSeal+HD Reenterable LV HV Power Cable Duct Seal System

Utility Applications

FiloSeal+HD duct seals are approved by both water and electrical utilities in the UK - accepted by UK DNO's for sealing substation ducts at LV-HV and with WIMES approval for use throughout the UK water utility network.

The FiloSeal+HD duct sealing system uses MD+ sealant which is easily applied using a skeleton gun. MD+ sealant is a high quality, flexible sealant which is based on a silicon compound which cures with air (humidity).

The unique hexagonal design of the FiloSeal+HD tubes makes positioning and separation of cables very simple whilst also providing a strong backing for the MD+ sealant to be applied on.

Duct Seal - 1

Duct Seal - 2

Duct Seal

Duct Seal - 3

Cable ducts seals are available for all sizes and configurations - contact T&D for specification, information and ordering details for duct seals not featured in the following table.

Cable Duct Seal Filoform FiloSeal+HD - Specification
FiloForm Part Number Description Maximum Duct Diameter (mm) Maximum Cable Diameter In The Duct (mm)
FiloSeal+HD 110 (280010) FiloSeal+HD 110mm Max Ø110mm Max Ø80mm 
FiloSeal+HD 160 (280020) FiloSeal+HD 160mm Max Ø160mm  Max Ø130mm 


Duct Seal Dangers 

Sub-standard cable sealing can lead to catastophic substation floods and power outages  - the installation of approved and reliable duct seals is an essential protection measure against flooded low, medium and high voltage substations.

Expanding foams, mastic seals and mechanical bungs are ineffective and certain to degrade and fail overtime.

Cable Duct Seals

Flooded Substations

Image: In December 2015 Storm Desmond caused electricity outages to 55,000 homes in the UK as relentless and rising rainwater flooded Mv-HV substations.

Filoform FiloSeal+HD Reenterable LV HV Power Cable Duct Seal System

Filoform provide cable duct seals to provide effective sealing to ducting against gas and water.

Filoform cable duct seal kits features a specially formulated expanding polyurethane which cures to a high density closed cell structure, ensuring a water and gas tight seal around cables entering service ducts with permanent and re-enterable cable ducts seals available.

Video: Multi-cable Sealing System FiloSeal+

UK DNO Distribution Network Operators

Filoform cable duct sealing systems are in widespread service on both DNO and private networks for sealing substations at 11kV, 33kV, 66kV and 132kV cable voltages.

Cable Duct Seals

Further Reading: 

Sealing Substation Cables - 33kV Single Core Trefoil & Multiple LV Power Using Filoform FiloSeal



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Filoform FiloSeal+HD Reenterable LV HV Power Cable Duct Seal System - Spec Sheet

Category:  Cable Transits & Duct Sealing

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