HIGH-VOLTAGE INSULATORS - · PDF fileLAPP Insulator - Your systems partner in high-voltage...
Transcript of HIGH-VOLTAGE INSULATORS - · PDF fileLAPP Insulator - Your systems partner in high-voltage...
LAPP Insulator - Your systems partner in high-voltage engineering
For over 100 years we have been supplying high-voltage insulators for electric power transmission and
distribution systems to customers world wide. Millions of ceramic and thousands of silicone
rubber insulators have been in service for decades without failure or problems. This performance has
won us the confidence of our global clientele. Products of uncompromising quality, backed by compre-
hensive expertise and the competence gathered through years of experience, have made us a preferred
supplier to the industry. Lapp Insulator insulators are among the safest and most dependable compo-
nents in high-voltage engineering anywhere.
Insulators in high-voltage systems are exposed to high and widely changing loads. Their electric insulating and mechanicalcapability must be ensured even under extremely adverse environmental conditions. An appropriate design of the insulatingmaterial to meet the specific requirement profile is an important prerequisite for achieving many years of reliable service.
Solutions through dialogue make the difference
When it comes to solving special high-performance insulating tasks, we not only bring to bear our entire application techno-logy expertise and long experience. From the outset of each project, we also make sure to obtain the appropriate input fromproduction, costing and logistics experts. This approach ensures that all success factors will be duly taken into account andthat the development of new insulator concepts will proceed quickly and efficiently. Simultaneous engineering saves timeand duplicate product trials, thereby cutting costs - a decisive benefit for the customer and ourselves in today`s competitiveenvironment. Even where special designs or models are involved, we will take into account volume production conditionsfrom the very start in order to enable an effective and cost-efficient manufacturing process.
Our high-voltage engineering components are producedunder a DIN ISO 9001: 2000 certified quality managementsystem. The aim of our production quality control is toachieve zero-defect performance at all manufacturing sta-ges. This goal can only be met through a complete under-standing, appropriate monitoring, and continuous improve-ment of all processes. By combining a set of process-specificmethods, we have created an all-inclusive system whichstarts with the inspection of incoming feedstock andextends throughout the production chain.
Additional detailed information on LAPP Insulator, our pro-ducts and services can be found in the Internet at www.lappinsulator.de
Harnessing all success factors
A ISO 9001: 2000 certified company
In shape for optimum performance
The exterior appearance of a high-voltage insulator depends on a combina-
tion of various factors determining its specific shape. Designing an insulator
for optimum performance requires an exact knowledge and description of
all application needs.
Environmental conditions at the installation site determine thedesign and number of insulator sheds. (See adjacent examples)
Environmental conditions
The mechanical forces such as bending moments, compression,tension, torsion, etc. acting on the insulator and its connectingsystem must be accurately specified.
Mechanical requirements
Data such as the lightning impulse flashover voltage, switchingimpulse flashover voltage and power-frequency flashover volta-ge define the necessary dielectric strength and insulator length.
Electrical characteristics
Creepage distances are defined in accordance with IEC 60815and with customers requirements.
Creepage distance requirements
International standards, codes and test specifications are observed in the manufacture of the product.
Applicable standards and testing codes
Special requirements (connecting dimensions, diameter, etc.)are considered during design.
Customer specifications and installation requirements
LAPP Insulator - provides leading edge solutions in electric power supply systems
A basic distinction is made between longrod insulators
exposed to tensile loading and line-post insulators subject
to compression and bending moments. Our product lines
includes both types, both made of technical ceramics or
composite synthetic materials.
LAPP Insulator insulators are puncture-proof and distinguis-
hed for their high mechanical resistance. Moreover, each
product is optimized for the individual ambient conditions.
Many years of continuous refinement have turned overhead
power line insulators into one of the safest components in
energy transmission engineering.
Insulators for high-voltage overhead transmission and traction lines
Single-part long-rod insulators made of technical ceramics are supplied in lengths of up to 1400 mm, with some specialdesigns availale up to 1900 mm. Greater lengths are achieved by combining several longrods into string configurations.
An alternative particularly for very long insulators is our system, which comprises single-part insulators foroverhead power lines in length up to 6 meters. 5-meter long insulators of this type, rated for SML = 450 kN, were suppliedto Canada for a 765 kV system already in 1978. In Los Angeles, insulators have been giving dependable servi-ce in a 500 kV d.c. system since 1984.
Given their lightweight design, our insulators are also suitable for phase spacing applications, thereby open-ing up new design options in the construction of compact overhead power transmission lines and traditional designs.
Pin-type line-post insulators may likewise be made of technical ceramics or synthetic composite material. One important fieldof application for medium-voltage insulators are traction wire systems. The use of our insulators in electric railroad tractionsystems, even on high-speed German Railway lines, testifies to our customers` confidence in the dependability on these components.
In switchgear systems our products are used as solid-type postinsulators and for disconnect switch rotary columns. Units up toa height of 2600 mm are of single-part design, with multi-partunits being employed for higher voltage levels.
For outdoor circuit breakers we manufacture hollow insulatorswith cylindrical or curved bores up to an overall height of 2600mm. These insulator types are required to exhibit a particularlyhigh mechanical resistance in addition to their electric stength - an easy task for LAPP Insulator insulators.
Insulators for high-voltage switchgear and substation equipment
Continuously enhanced - the productionprocess of high-performance ceramicinsulators
Over the decades we have refined the manufacture
of ceramic insulators to perfection. Highly sophistica-
ted monitored processes form the basis of a produc-
tion system in which small customized product runs
are implemented with the same precision and reliabi-
lity as standard volume parts. Our improvement
management system ensures an ongoing refinement
of all processes and continuous advancement in cost
efficiency.
Kaolin
Clay
Alumina
Felspar
Mixing and grinding
Filter pressing
Extrusion
Pre-drying
Machining
Drying
Glazing
Sintering (Firing)
Mounting of metal parts
Selected ingredients of high purity and homogeneous
properties are weighed, mixed to formula specifica-
tions, and subjected to a grinding process. Vacuum
extrusion presses form the plastic filter cake into
cylindrical blanks (“body”) which are subjected to a
closely controlled drying process to condition them
for the following shaping steps.
Vertical lathes are used to machine the blank to its
desired contour. After a further precision drying stage
the unfinished insulator already possesses a high
strength due to the clay bond and is ready for the
application of the glazing by an immersion process.
The subsequent firing stage creates the very hard
ceramic structure.
The insulating body is now equipped with its metal
hardware to complete the production process. It is
then tested to international standards or customer
specifications. For this purpose we maintain a high-
voltage testing laboratory in which voltages up to 3
million volts can be generated.
The insulator blank has sufficient strength to beglazed by immersion.
A cylindrical blank is obtained by vacuum extrusion.
A precision-controlled drying process conditions the blank for thesubsequent produktion stages.
Blanks are machined to their specified contours in avertical lathe.
Insulators are fired at approx. 1350°C.
The high-voltageinsulator System - advanced technology
As an alternative and complement to our range of proven ceramic insulators we have
continued the development of composite insulators made of high-grade synthetic
materials. These products have been noted for their reliable performance in the field
since 1967. Our system insulators consist of two components, i.e., a rod
or tube made of glassfiber reinforced plastics
(FRP) and a silicone elastomer housing covering
the FRP rod. This design allows a separate impro-
vement of the system`s mechanical properties
(determined by the FRP component) and electrical
performance (determined largely by the silicone
rubber sheath). As a result, our
insulators exhibit outstanding mechanical and
electrical characteristics exceeding all overhead line and switchgear engineering require-
ments.
Modern composites - the key to success
• Outstanding resistance against environmental fac-tors such as UV light, ozone, acid, contamination and moisture
• Interior tensile strength higher than steel, despite approx. 75% less weight
• High resistance against discharges and leakagecurrents
• Drastically reduced leakage currents due to hydro-phobic properties (see illustration)
• High explosion resistance of hollow insulators in case of internal pressure build-up
silicon rubberinsulators are particularlysuitable for
• high contamination applications
• vandalism hazards
• high creepage on a shortlength
• compact line applications
Key features of compositeinsulators
Used in major utility networks of the worldTestimony to confidence through experience
Complete reference list available on request
With decades of unsurpassed service reliability silliconerubber insulators have and still provide the best solution world wide inall climatic and pollution conditions.
All voltage levels since 1964
All voltage levels since 1975
All voltage levels since 1975
All voltage levels since 1976
All voltage levels since 1978
All voltage levels since 1984
All voltage levels since 1985
All voltage levels since 1985
All voltage levels since 1985
All voltage levels since 1990
All voltage levels since 1993
All voltage levels since 1991
EUROPE
SOUTH AFRICA
U.S.A.
AUSTRALIA
SOUTH AMERICA
NEW ZEALAND
EMIRATES
SAUDI ARABIA
NORTH AFRICA
SPAIN
INDIA
CHINA
Patented manufacturing expertise for Isolators
The first manufacturing stage is the continuous pul-
trusion process yielding the FRP rod. The combination
of a hydrolysis resistant epoxy resin with acid resistant
glass fibers (ECR glass) is a safe assurance against
brittle fracture. Rods are cut to length and visually
inspected before being coated with a seamless sheath
of high-temperature vulcanized (HTV) silicone rubber
ensuring optimum adhesion. Prefabricated sheds are
mounted on to the rod to complete the insulator.
A subsequent vulcanizing stage creates a durable
high-strength bond between the sheds and the rod
sheath. The metal hardware is mounted by a cold-for-
ming process and all insulators are subjected to
mechanical inspection, after which the joints between
the FRP rod and the metal components are sealed
with a special silicone elastomer. This metastable
compound creates a perfect seal which prevents the
ingress of moisture for an unlimited period of time.
A modular system comprising FRP rods of different
diameters and any desired length up to 6 meters,
various shed configurations ( shapes, numbers, spa-
cings) and a wide range of assorted end fittings
allows the longrod insulator to be
optimized for any specific application.
Pultrusion of the FRP rod
Application of HTV silicon sheathing
Shed mounting and vulcanization
Mounting of metal end fitting and sealing
A modular system of variable lengths, different shed shapes and sizes and a matching range of metal end fittingsallow insulators to be customized for any conceivable application.
The sheds and rod sheath are joined by vulcanization.
FRP rods are seamlessly coated with HTV silicon.
Safe and durable sealing is achieved by a speci-al process.