An article by Roxtec Ltd's managing director, Clive Sharp, looking at how cable and pipe seals can be used to protect electrical equipment.

1. Roxtec has developed a reputation for sealing
cables and pipes entering structures and its
products are now increasingly being used to
protect equipment. There are multiple hazards
to consider with cable entries including light-
ning, gas, fire, dust, flood, humidity, rodents,
electro-magnetic disturbances and the risk of
explosion. However, traditional sealing sys-
tems only tend to protect against one particu-
lar hazard. The effective protection of electrical
equipment in manufacturing, power, industrial
and hazardous environments has become
a major engineering challenge. In addition,
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Cable & wire
Sealing cables
over land and sea
Roxtec has specialised in the delivery of
sealing solutions for panel building and
system integration for more than two decades
with the firm’s seals being used within the most
demanding environments on land and at sea all
over the globe.
The effective protection of electrical equipment in
manufacturing, power, industrial and hazardous
environments has become a major engineering challenge.

2. industry is calling out for cable transit devices
which can significantly reduce the quantity,
size and weight of cable sealing systems.
Withstanding high
water pressure and
preventing ingress
A recent project within the wastewater sector
saw Roxtec involved in a £220m water
treatment upgrade project in London. This
involved the supply of multi-cable transit seals
to Thames Water for its Crossness Sewage
Treatment Works - the second largest in Eu-
rope. Roxtec’s seals were used throughout the
site to help protect one of Greater London’s
last remaining grazing marsh lands. The major
project enabled the site east of the capital to
treat 44pc more sewage than its previous ca-
pacity. The upgrade also significantly reduced
the amount of storm sewage that overflows
into the River Thames when the site becomes
overloaded due to rainfall. Renewable energy
sources on site include a wind turbine and
thermal hydrolysis plant (THP).
The THP works as an industrial-scale
‘pressure cooker’ to heat sludge, the leftover
solids from wastewater treatment, to around
160 °C. It produces up to 50pc more biogas
which is then burnt to create heat to gener-
ate renewable energy. Roxtec’s seals were
selected because of their durability and
flexibility - they can withstand extremely high
water pressure and prevent water ingress
which is vital in a project of this nature. They
are used specifically to seal power and control
cables in the water works, the THP and the
wind turbine. The gas tight seals also help to
protect local wildlife by preventing sewage
from entering the River Thames while guarding
against fumes. The IP67 rated seals further aid
Thames Water in protecting its assets against
other hazards such as fire and vermin.
Effective sealing for
multiple cables and
pipes
When building the Project Q Data Centre in
Queretaro, Mexico, the owner representative
Santander Global Facilities México faced
a real challenge sealing cable and pipe
penetrations. The project required multiple
cables and pipes to be routed through a
45-centimetre thick wall while maintaining
integrity. Construction coordinator DIINESA
specified Roxtec cable entry solutions. Due
to the sensitive equipment within the data
centre, the construction project required all
perimeter walls to be completely watertight
and weather resistant. The walls were also
to be fire resistant and capable of keeping
out rodents and insects. It was obvious that
the traditional cable sealing method, which
consisted of a portion of pipe cast into the
wall with intumescent mastics, would not
work. However, Roxtec’s seals are area
efficient and easy to adapt to cables and
pipes of different sizes.
The installers from Lebanc handled cables
ranging from 13mm to 34mm in diameter
and pipes from 29mm to 305mm. The seals
can be opened to provide spare capacity.
Due to the high safety demands, special
concrete mixtures and last generation water-
proofing were used to ensure the wall surface
was impermeable. Naturally, the cable and
pipe transits had to meet the same strict
requirements. However, the huge perimeter
wall was made of high strength concrete
making it difficult to open a passage for ad-
ditional installations in the future. That is why
the goal was to leave transit preparations for
easy upgrades. It was crucial to find a way
of holding together many pairs of sleeves
with a sealing system at a distance of 45cm.
DIINESA and Roxtec managed to solve the
problem – with custom made steel structures
that were cast between the sophisticated
grillage foundation allowing only small toler-
ances between walls. The steel structures
hold together seals and frames through a
pair of sleeves connected with paper casting
moulds.
Quick and easy cable
replacement
When designing the spreaders, extruders
and ovens for the global baking industry,
Haas-Meincke A/S was keen to incorporate
a cable sealing solution which could keep
dust out and prevent water from entering
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Due to the sensitive equipment within the data centre,
the construction project required all perimeter
walls to be completely watertight and weather resistant.

3. and damaging equipment during high pres-
sure hosing. Haas-Meincke A/S developed
the machines to ensure high reliability in
production and a high level of hygiene. How-
ever, its former cable sealing solution, using
cable glands, often gave rise to problems
due to the accumulation of debris. Roxtec
seals now ensure that cable failures are less
frequent, which helps avoid unnecessary
machine downtime. If a cable should fail,
replacement is quick and easy even if the
cables are of different sizes and pre-termi-
nated at both ends. Haas-Meincke A/S now
consciously designs its products to incorpo-
rate Roxtec seals right from the start. A key
advantage is that Roxtec can offer a 100pc
integrated solution for those machines with
stringent requirements for water-tightness
and ease of cleaning.
Customised bulk-
head and deck seals
Another area Roxtec is driving innovation
is the offshore windfarm sector. Roxtec
was recently involved in a project in the
North Sea. The firm delivered cable transit
systems - which are a key safety compo-
nent to safeguard workers, structures and
equipment. The systems are located on
a substation platform created as part of
the Dudgeon Offshore Windfarm, sitting
20 miles offshore near the seaside town
of Cromer in North Norfolk. It involved the
delivery of customised bulkhead and deck
seals designed to be flexible with easy
maintenance access and spare capacity
for upgrades. They are both easy to install
and inspect. The cable sealing systems
are further designed to meet the long-term
lifecycle of the 402MW wind farm whose
turbines will provide power to 410,000
UK homes and is set to be commissioned
during 2017.
Roxtec delivered A0/A60 bespoke seals for
HV and MV applications on the substation
platform. They also seal array cables to MV
switchgear and cables from MV switchgear
to transformer input. Additional products
have been used on the platform’s cables
linking its transformer to its Gas Insulated
Switchgear (GIS) and on export-to-shore
cables. Roxtec has now been involved in
cable sealing projects across more than 40
offshore wind farms in Europe. Seals are
used for different applications in windfarm
projects, from control cabinets to genera-
tors and converters. They offer protection
against fire, gas, water pressure and corro-
sion and provide cable retention.
Passing on
knowledge
Due to the knowledge acquired over many
years, Roxtec has devised a programme of
accredited technical CPD seminars covering
the importance of sealing cables and pipes
in a variety of industries. These are based
upon industry standards and Roxtec’s own
practical experience.
Clive Sharp, UK Managing Director at
Roxtec
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Seals are used for different applications in windfarm
projects, from control cabinets to generators
and converters.