1. SYLGARD®
High Voltage Insulator
Coating
Proven protection against pollution
The same formulation for more than 25 years
To deliver products and services which safely
solve today’s problems and prevent tomorrow’s

2. SYLGARD High Voltage Insulator Coating
The reliable, cost-effective, long term solution to pollution induced
flashovers of high voltage insulators.
Insulator contamination has been a problem since the birth of SYLGARD HVIC, high reliability,
electrical power distribution. Salt spray, industrial pollutants, low lifetime running costs
and even desert sand can lead to costly power interruptions due
To deliver the performance required by demanding maintenance
to arcing and flashover. While numerous attempts with other
engineers, SYLGARD HVIC was formulated and put to the test
protective methods have had their limitations, there is a solution
globally by several major electrical utilities and many high voltage
that utility maintenance engineers can rely on: SYLGARD High
laboratories. It was found to resist corona, ultraviolet light, water
Voltage Insulator Coating (HVIC).
erosion and the accumulation of airborne particle contamination.
Researched and developed by Dow Corning Corporation in the
During the last 25 years SYLGARD HVIC has demonstrated its
early1970’s in response to utility engineers requirements for
superiority in providing long term, virtually maintenance free,
longterm protection against pollution, the SYLGARD HVIC
flashover protection of high voltage insulators in polluted
formulation has remained unchanged for more than 25 years.
environments.
A long history of successful performance in highly contaminated
areas has proven that SYLGARD HVIC provides superior arcing The high performance of SYLGARD HVIC is a direct result of
and flashover protection in the most hostile environments. It lasts its weather resistance and electrical characteristics. These special
longer than other coatings and greases, providing significant features include:
savings in maintenance and replacement costs. One application
of SYLGARD HVIC generally leaves insulators virtually
• Long-term water repellency/hydrophobicity. This is invaluable
to high voltage applications because without it, contaminants
maintenance free for many years.
on the surface of the insulators become wet and produce a
conductive layer of ionisable material. This contributes to
an increase in leakage current and probable flashover.
The problem with other “solutions”
Previous methods to protect insulators from flashover caused by
• Resistance to atmospheric and chemical degradation. The
coated insulators remain unaffected by salt air, airborne
pollution have included changes in insulator design to provide
pollutants, rain or humidity.
longer leakage paths and installation of conductive glazed
insulators to ensure continuous surface-drying currents. • Resistance to arcing and corona. SYLGARD HVIC does not
degrade to conductive by-products when exposed to electrical
Changing insulator specifications to provide longer leakage paths
discharge.
results in increased weight and higher initial costs. Although an
improvement, these installations still require frequent washing
or greasing in polluted areas.
Conductive glazes often lose stability and increase losses through
their consumption of electricity. The result is lower reliability,
higher running costs and frequent insulator changes 132kV substation at Anglesey
Aluminium Metals, UK. Les Ankers,
the substation maintenance
Frequent water washing or repeated applications of hydrophobic
engineer, commented “before we
greases are also methods used to combat pollution. applied SYLGARD HVIC we were
always on a knife edge when
frequent flashovers almost stopped
Water washing requires expensive equipment and has to be the smelting process, however
repeated frequently. The hydrophobic grease technique is labour since the application of SYLGARD
HVIC 10 years ago we have not
intensive, messy and disliked by linemen. Neither of these experienced a single flashover. In
addition we have eliminated the
methods provides the long-term protection expected by the need for insulator cleaning and
modern utility maintenance engineer. greasing”.
© 1998, 2001 Dow Corning Corporation. All rights reserved.

3. High reliability, long service means lower lifetime costs.
With SYLGARD HVIC, one application does it all – for years, SYLGARD HVIC – the superior coating
eliminating the need for repeated water washing or greasing and
We at Dow Corning believe that SYLGARD HVIC is clearly
this results in significant savings in maintenance and replacement
superior. Only SYLGARD HVIC – with its unchanged formulation
costs. Time and again SYLGARD HVIC has proven the long
over the last 25 years and combined with an unparalleled field
lasting, reliable and most economical solution.
application history can provide true peace of mind, long term,
SYLGARD HVIC is supplied as a white, one part room uninterrupted reliability and lowest life time running costs.
temperature vulcanising (RTV) silicone elastomer dispersion in
a high flash point (40°C [104°F]) naphtha spirits solvent.
Prove it for yourself
The product provides un-primed adhesion to glass and porcelain
insulators and can be applied by spraying, brushing or dipping. We challenge you to complete an economic evaluation for your
Recommendations on proper application, dilution techniques own specific situation. You’ll discover that SYLGARD HVIC
and spraying equipment are covered in the SYLGARD HVIC delivers more than just superior performance and better long-term
application guide. SYLGARD economics. Why? Because SYLGARD HVIC delivers long-life
HVIC is normally applied in two performance without the need for costly repeated maintenance
to three coats depending on the procedures. We will provide you with a simple computer cost
type of spraying equipment being model which will allow you to compare the costs of installing
used. A 10 to 15 minute drying SYLGARD HVIC versus the application of greases or water
time between coats is required washing to generate a typical lifetime cost curve similar
dependant on the temperature to the example shown below.
and humidity.
Maximum protection and life
SYLGARD HVIC - the lowest cost in the
expectancy is achieved with
long-term
a cured thickness of 0.5 mm
(0.020 in). The white colour On a one-time basis in a typical installation, water washing is
Insulator coated with
SYLGARD HVIC and covered allows visual inspection for usually the least expensive protection against pollution-induced
with iron ore dust, 10 years on
uniform coating and the flashovers. However water washing needs to be repeated regularly
it still shows excellent
hydrophobicity. identification of thin spots. so to evaluate the long term costs of water washing vs. grease and
SYLGARD HVIC, a typical calculation as below should be
Porcelain and glass surfaces should be dry and clean before
untertaken:
application. If silicone (or other) grease has been previously used
on the insulators, this should be completely removed by wiping
and the surface cleaned with isopropyl alcohol before application Cost, $ Total costs for one 45kV insulator over 15 years
1000
of the SYLGARD HVIC.
900
800
Long field-testing proves quality 700
600
For more than 25 years Dow Corning customers have been using 500
SYLGARD HVIC throughout the world – from Argentina to 400
Alaska, from Saudi Arabia to Singapore, and test sites such as 300
these have proven that SYLGARD HVIC is the superior coating.
200
At many of the test sites, arcing and flashovers had been causing 100
frequent outages – up to once a month. In most cases, once 0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
SYLGARD HVIC was applied, arcing and flashover were Time, years
eliminated. Water washing Silicone grease SYLGARD HVIC
Total $900 Total $468 Total $67

4. Assumptions for this specific calculation:
• Material/labour costs to water wash one 45kV insulator one time: $15*
• Material and labour costs to coat one 45kV insulator with silicone grease one time: $55*
• Material and labour costs to coat one 45kV insulator with SYLGARD HVIC: $67*
• Water washing is repeated every three months
• Grease application repeated every two years
• SYLGARD HVIC anticipated life for this example: 15 years
* Costs vary; these are in the ranges given to Dow Corning by several utilities
In-use service conditions vary widely, so Dow Corning cannot warrant a 15-year life for each installation. The predicted lifetime will depend
on the pollution severity and the type of installation and how well it was designed. The cost model provided will allow you apply the specific
details which relate to your specific situation, the type and size and numbers of insulator(s), your own experience of water washing or the use
of grease, together with local costs of labour and materials. You can then work out the lifetime cost advantage of using SYLGARD HVIC for
yourself in your own specific situation
Your Global Connection
Asia North America
Dow Corning Asia Ltd. - Japan Dow Corning Corporation
Tel.: +81 3 3287 1151 World Headquarters
Tel.: +1 989 496 6000
Dow Corning Asia - Singapore
Tel.: +65 253 6611 South America
Dow Corning do Brasil
Australia & New Zealand Tel.: +55 11 3759 4300
Dow Corning Australia Pty. Ltd.
Tel.: +61 1300 360 732
Europe
Dow Corning Europe
Tel.: +32 (0) 64 880 000
LIMITED WARRANTY INFORMATION - PLEASE READ CAREFULLY
The information contained herein is offered in good faith and is believed to be accurate. However, because
conditions and methods of use of our products are beyond our control, this information should not be used
in substitution for customer's tests to ensure that Dow Corning's products are safe, effective, and fully
satisfactory for the intended end use. Suggestions of use shall not be taken as inducements to infringe any
patent. Dow Corning's sole warranty is that the product will meet the Dow Corning sales specifications
in effect at the time of shipment. Your exclusive remedy for breach of such warranty is limited to refund
of purchase price or replacement of any product shown to be other than as warranted.
DOW CORNING SPECIFICALLY DISCLAIMS ANY OTHER EXPRESS OR IMPLIED
WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE OR MERCHANTABILITY. DOW
CORNING DISCLAIMS LIABILITY FOR ANY INCIDENTAL OR CONSEQUENTIAL
DAMAGES.
WE HELP YOU INVENT Dow Corning and SYLGARD are registered trademarks of Dow Corning Corporation.
THE FUTURE.TM TM
WE HELP YOU INVENT THE FUTURE is a trademark of Dow Corning Corporation.
© 1998, 2001 Dow Corning Corporation. All rights reserved.
www.dowcorning.com
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