HIGH-VOLTAGE INSULATORS - · PDF fileLAPP Insulator - Your systems partner in high-voltage...

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HIGH-VOLTAGE INSULATORS

Transcript of HIGH-VOLTAGE INSULATORS - · PDF fileLAPP Insulator - Your systems partner in high-voltage...

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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.

LAPP Insulator GmbH & Co. KGBahnhofstrasse 5D-95632 WunsiedelGermany

Phone: +49 (0) 9232 / 50-192Fax: +49 (0) 9232 / 50-106www.lappinsulator.de