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Hard paste porcelain is also known as true porcelain. Out of all the wide varieties of ceramics, true porcelain is the hardest and the most durable—which is one of the reasons porcelain insulators largely replaced glass insulators, beginning in the nineteenth century.

True porcelain was first created in China, and to this day that country is the source of most superior porcelain products, such as electrical porcelain insulators. In fact, the world’s largest manufacturer of electrical porcelain insulators is located in Dalian, China.

During the Tang Dynasty (618-907) hard paste porcelain was created from the ceramic known as stoneware. Stoneware is material made when clay is fired at high heat—1,200 degrees C to 1,315 degrees C (2192 F to 2399 F.) Stoneware is non-porous and impervious to liquids even when not glazed. Sometime during the Tang Dynasty, the Chinese mixed kaolin—a pure white clay—with petuntse, a type of feldspar found only in China, and began to make porcelain products. Since kaolin is extremely resistant to high temperatures, they could fire the mixture of kaolin and petuntse at heats between 1,250 degrees C to 1,450 degrees C (2280 F to 2640F.) At those extreme temperatures, the petuntse melts into a non-porous natural glass and fuses with the kaolin. The body and glaze become one solid material. When you break apart a piece of true porcelain products, it’s impossible to differentiate between the two materials used.

In addition to its amazing hardness and strength, true porcelain is well known for resisting electrical conductivity, which makes it the ideal material with which to manufacture insulators and transformer bushings.

Porcelain insulators were first used in the 1850’s for telegraph insulators. Although at that time they were not in common use. Glass insulators were still preferred. For one reason, they were cheaper than porcelain insulators. In addition, people thought the clear glass insulators would discourage insects from building nests in or around them.

However, the need for electrical power distribution in the 1880’s demanded insulators that were much larger and stronger than the glass insulators currently in use. Insulators had to be manufactured that could resist conductivity for lines carrying tens of thousands of volts.

As the demand for porcelain insulators rose, some companies produced them using dry press porcelain. Dry press is easier to manufacture than wet press porcelain. It’s made by pressing mostly dry, granular porcelain into molds. However this method of producing porcelain insulators leaves tiny cracks and holes in the clay, rendering such insulators risky for distributing high voltages of electricity. In the late 19th Century, manufacturers increasingly turned to wet press porcelain for use in electrical porcelain insulators. Wet press porcelain, as the name suggests, is made while the porcelain is wet, making sure to remove all air from the clay before shaping it in molds and firing. It lacks the tiny holes found in dry press porcelain and is therefore the best material to use in porcelain insulators.

This was dramatically demonstrated in 1896 when electrical porcelain insulators were chosen for use on the first line to distribute power from Niagara Falls. Various companies submitted samples of their electrical porcelain insulators in a competition to win the contract to supply porcelain insulators for the Niagara-Buffalo transmission line. All the insulators submitted were made from dry process porcelain, except one—the electrical porcelain insulator made by the Imperial Porcelain company. All the insulators were tested in brine at 40,000 volts, and only the one made by Imperial—the wet process electrical porcelain insulator—passed the test.

From that day on, it has been widely recognized that the strongest, most durable type of porcelain available provides the greatest range of benefits in the manufacture of electrical porcelain insulators.

With over 25 years experience in the global electric power industry, Meister International has been distributing porcelain insulators and porcelain bushings for more than 7 years, successfully meeting the demands of our customers with unparalleled quality and service. We serve industries around the world, and our satisfied customers include large utilities, bus-duct packagers, high-voltage switchgear and transformer manufacturers, repair shops and others.

Meister International is a full-line supplier of:

• Porcelain line post insulators
• Station post insulators
• Porcelain standoff insulators
• A-20 bus insulators
• A-30 bus insulators
• Porcelain transformer bushings
• Circuit-breaker and custom manufactured bushings
• Porcelain Capacitor Bushings
• Porcelain spool insulators

The Meister Advantage:

Avoid the frustration of long lead times and high prices for porcelain insulators and bushings by taking advantage of our stocking agreements that lower your on-hand inventory, guarantee supply chain continuity, and shorten lead times of finished goods.

We distribute products manufactured by leading porcelain manufacturers. These high quality porcelain insulators are designed, manufactured and tested per ANSI standards. A-20 and A-30 insulators are assembled using Portland cement to prevent loose inserts. Indoor standoff insulators are constructed of the highest quality wet porcelain to provide reliable, long life. Our station post insulators offer maximum economy as well as trouble-free service, and are rated 95kV BIL through 2050kV BIL for operating voltages from 7.5kV to 1100kV. Station post insulators meet or exceed all ANSI standards in electrical or mechanical ratings for their voltage class.

Among the exceptional features of Meister porcelain insulators are resistance-graded porcelain, improved contamination performance, improved RIV performance, solid-core construction, puncture proof bodies, consistent mechanical strength, radio / TV interference-free, choice of semi-conductor glazes, and above all, durability.

Porcelain Insulator Applications

Porcelain insulators are used for a wide variety of applications due to their high resistance to the passage of electricity (also known as conductivity). Also known as electrical ceramics or ceramic insulators, porcelain insulators provide insulation in situations where high temperature or high voltage is present.

The first electrical systems to make use of insulators were telegraph lines, because direct attachment of wires to wooden poles was found to give very poor results, especially during damp weather.

Porcelain holds its shape and size under pressure. This is important in switching applications where the insulator is used to open and close electrical contacts in a thermostat or pressure switch. Porcelain is very abrasion resistant and offers long life in applications where other materials would wear out quickly.

High voltage insulators are also able to resist heat, chemicals, weather and bacteria without allowing them to affect their properties or alter their structure, and also offer dimensional stability and rigidity.

Ceramic insulators also have many applications in the foundry and refractory industries because they can withstand thermal shock, even molten metal, and still maintain their rigidity. The aerospace, automotive, marine, medical and transportation industries often use ceramic insulators for various purposes as well.

Insulators used for high-voltage power transmission are made from glass, porcelain, or composite polymer materials. Although glass has a higher dielectric strength, it attracts condensation and the thick irregular shapes needed for insulators are difficult to cast without internal strains. Some insulator manufacturers stopped making glass insulators in the late 1960s, switching to porcelain materials instead. Composite insulators are less costly, lighter in weight, and have excellent hydrophobic capability; however, these materials do not yet have the long-term proven service life of porcelain.

By definition, an insulator is a material that resists the flow of electric current. An insulating material has atoms with tightly bonded valence electrons. These materials are used in parts of electrical equipment, also called insulators, intended to support or separate electrical conductors without passing current through themselves. The term is also used more specifically to refer to insulating supports that attach electric power transmission wires to utility poles.

An insulator is typically comprised of an insulating core that extends between two electrodes which are maintained at significantly different electrical potentials. Insulators have been made with various materials. High voltage electrical insulators for use at voltages in excess of about 1000 volts, and typically at 34.5kV, can be made from porcelain, glass fibre, or solid polymeric material.

Porcelain insulators have outstanding electrical properties and are the preferred insulator for utility substations. Porcelain insulators offer much higher load-bearing ratings over glass and polymer insulators. Porcelain insulators are made from clay, or alumina, and are covered with a smooth glaze (typically gray or brown) to shed water.

While glass has a higher dielectric strength than porcelain, it attracts condensation and the thick irregular shapes needed for insulators are difficult to cast and manufacture without internal strains. Some insulator manufacturers stopped making glass insulators in the late 1960s, switching to ceramic/porcelain materials.

Recently, some electric utilities have begun converting to polymer composite materials for some types of insulators. These are typically composed of a central rod made of fibre reinforced plastic and an outer weathershed made of silicone rubber or EPDM. Composite insulators are less costly, lighter in weight, and have good hydrophobic capability. This combination makes them ideal for service in polluted areas. However, these materials do not yet have the long-term proven service life of porcelain insulators.

Porcelain insulators were constructed as early as the 1850s, but glass was still more popular since it was more affordable, however electricity was not what it is today. About thirty years later, electricity was being distributed in higher voltages and porcelain proved to be better fit for the job. Many insulator manufacturers stopped making glass insulators in the late 1960s after switching to ceramic ones.

Porcelain can be used to create bushings; the hallow insulators that have a conductor inside of them. Some other electrical products include indoor porcelain bus insulators, indoor standoff insulators, and station post insulators. If your current glass insulators are doing the job, consider making the switch to the higher quality porcelain products to improve the efficiency of your business.

Such products are made from the highest quality of wet porcelain, which is a method used to prevent cracking in the insulator. These porcelain insulators provide strength and the long life for reliable substation operation as well as providing maximum economy. Making the switch from glass to porcelain has many advantages such as reducing electrical consumption and making efficient use of the energy already being consumed. This electrical switch would be considered a smart, green industrial upgrade for your company.

Other advantages to using porcelain electrical products include stability, material strength, low cost, and earthquake resistance. Since porcelain insulators have been in use for more than 100 years, they have proven to be resistant to environmental aging. Porcelain is stable in its structure and will not be damaged by environmental stresses such as humidity, UV light, or electrical activity. Although porcelain insulators are available in many shapes and sizes, its rigid nature provides great mechanical strength. The porcelain used for bushings on high-voltage transformers can stand alone, without the use of other materials.

For decades, glass was the predominate material used for manufacturing electric insulators, but today the porcelain insulator has become the standard for power substations due to its greater strength and surface resistance compared to glass and other non ceramic insulators (NCIs).

The advantages of porcelain insulators include superior electrical properties, good mechanical properties (especially tensile strength), good creep resistance at room temperature, high corrosion resistance, minimal leakage problems, and less adverse effects from changing temperatures.

While it is possible for a porcelain insulator to be damaged by rough handling, acts of vandalism, or from flashover, the glaze usually sustains only superficial damage. The electrical or mechanical strengths are usually not affected, so change-out is not required. In cases where vandal damage has occurred, the extent of damage can be spotted from the ground using binoculars, and the need for change-out is easily determined. Vandal-damaged porcelain insulators do not impose immediate operational risks, either mechanically or electrically.

NCIs are more easily damaged than porcelain insulators. Damage can occur during handling, shipping, and construction. Due to the fact that NCIs are smaller than porcelain insulators, close-range inspection is often required to determine the extent of vandal damage. To inspect the insulator, an outage may be necessary to safely assess the damage at close range. NCIs damaged by vandals may require change-out or monitoring.

During production, insulator manufacturers test porcelain products insulators to confirm both electrical and mechanical strengths. NCIs are only tested mechanically. Moreover, porcelain insulators can be installed live, while NCIs should not.
Various tests can determine the electrical integrity of a porcelain insulator, and mechanical integrity can be determined visually. A complete loss of the porcelain shell of an insulator will result in a reduced strength, but not low enough to jeopardize the insulator's ability to support the line.

Routine maintenance, such as water washing or dry cleaning, removes contamination and restores porcelain insulators to their original insulation strength, preventing flashover. Porcelain repairs and maintenance methods for porcelain electrical insulators are well developed, and various industry application guides are available.

Although NCIs' flashover performance is generally considered better than porcelain insulators, they cannot withstand the heat produced from leakage current and dry band arcing as well as porcelain. Therefore corrosion occurs, exposing the core to moisture and voltage, leading to tracking of the core and insulator failure.

The major drawback of glass is that moisture condenses easily on its surface, limiting its use to lower voltages. With the advent of electric power distribution in the 1880's, larger and more reliable electrical insulators were needed to carry the higher voltages of power lines, which reached into the tens of thousands of volts. Glass was simply not sufficient enough to handle that level of voltage.

A number of insulators manufacturers began producing porcelain insulators and, from around 1915 on, the porcelain insulator virtually replaced the glass insulator on all electrical distribution, even at low voltages, as porcelain's superiority was demonstrated in both insulation quality and strength.
Apart from acts of vandalism, and rare poor quality-control issues, porcelain insulators have served the industry well, and users have attained a significant level of confidence in their long-term reliability. Maintenance methods are well established, and porcelain insulators commonly outlive their 40- to 50-year life expectancy.

Glass and other non ceramic insulators, however, have not yet attained the same level of experience or standardization, and their weaknesses are still being discovered.

For nearly a decade, Meister International has been serving customers in the global electric power community. They distribute only the highest quality porcelain insulators and porcelain bushings to large utilities, bus duct packagers, high-voltage switchgear and transformer repair shops and more.

Meister supplies three line post insulators: Clamp Top Post Insulators, Tie Top Post Insulators and NE Post Insulator "F" Neck Type. All are rated with a strength ranging from 25-66kV and are manufactured and tested to the requirements of current ANSI standards.

Designed for both durability and longevity, line post insulators supplied by Meister outperform non-ceramic insulators – NCI’s. Plus, the glaze coating on the exterior of the insulator keeps dirt and pollutants from adhering, requiring little, if any, maintenance. They provide years of service in the most unforgiving environments, such as extreme cold and heat, seismically active areas and corrosive situations such as seaside and petrochemical facilities. Sourced from only the finest manufacturers, their high-quality porcelain ensures operation at the desired voltage often beyond the 40 to 50-year expected service life of the insulator.

Manufacturers, packagers, and distributors of switchgear, power transformers, gensets and bus-duct continue to use porcelain electrical insulators over epoxy, silicone, and psycloalaphatic designs. Because they are nearly indestructible, utility engineers and consultants continue to specify porcelain insulators for their key switchyard projects.
These factors result in less downtime, maintenance and expense – making Meister the quality source for porcelain insulators.

The manufacturing process of high-quality porcelain insulators does take time, and to directly address this problem, Meister maintains an inventory of industry-standard insulators from only the best suppliers. They also offer stocking agreements so your production process doesn’t incur outages or downtime.

To request a quote or for additional information on Meister International Line Post Insulators or any of their world-class porcelain insulators and bushings, visit their website at MeisterIntl.com or call 513.923.2712.

For nearly a decade, Meister International has been serving customers in the global electric power community – including large utilities, bus duct packagers, high-voltage switchgear and transformer repair shops and more.

Meister distributes pin type insulators for both low and high voltage applications. All three classes of porcelain pin type insulators supplied by Meister are manufactured and tested to the requirements of current ANSI Standards.

Designed and manufactured with both economy and the installer in mind, porcelain pin type insulators supplied by Meister can be installed quickly and conveniently. The high-quality glaze coating on the exterior of the insulator keeps dirt and pollutants from adhering, requiring little, if any, maintenance. Any metal used in the manufacture of the post will not corrode or deteriorate, even in extreme conditions and often beyond the 40 to 50-year expected service life of the insulator. These factors result in less downtime, maintenance and expense – making Meister the quality source for porcelain insulators.

The manufacturing process of high-quality porcelain insulators does take time, and to directly address this problem, Meister maintains an inventory of industry-standard insulators from only the best suppliers. They also offer stocking agreements so your production process doesn’t incur outages or downtime.

To request a quote or for additional information on Meister International easy-to-install Pin Type Insulators or any of the world-class porcelain insulators and bushings in their product line, visit their website at MeisterIntl.com or call 513.923.2712.