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Hollow Insulator


Hollow Insulator

Hollow Insulators are used basically in the residential properties for protecting the internal components of the original equipment from different types of weather conditions. They also help in providing outer insulation to the property.

The hollow insulators are used in:

  • Circuit breakers- SF6/ Vacuum, etc.
  • Current Transformers
  • Potential Transformers
  • Capacitive Voltage Transformers
  • Surge (lighting) Arrestors
  • Power Transformers Brushings
  • Wall through Brushings
  • ESP Controlling Equipment

The hollow insulators are subject to internal pressure as well as mechanical load and thus needs some special expertise in terms of design, manufacture as well as testing of the insulators.

While the process of manufacture happens, the hollow insulators are subject to strict process and dimensional controls. The whole process of turning, drying as well as firing needs to be followed for making sure that proper verification of the shells which could be cut for meeting the specific dimensional needs. The surface finish is also maintained for preventing the oil or gas leakage. Then the insulator shells are assembled with metallic parts (wherever required) by using Portland cement on the assembly texture and then the water and air curing is done. Thereafter, the insulators are subjected to the required routine and acceptance tests in line with the requirements of the customers and the standards of the industry.

Insulators are basically the materials which inhibit flow of the electric current. The bang opposite of a conductor that permits electrical particles to freely flow, the insulators are intended in the household appliances as well as electric circuits for providing protection. Thermal insulation is also quite similar, but it mainly constricts heat flow as compared to electricity.


Insulators have a high resistance as well as low conductivity. They have atoms which have very tigh bound electrons which don’t move across the material. Since the electrons are always static as well as not roaming freely, the current is not able to pass so easily. Apart from protecting the current loss, the insulators also make the electric current efficient mainly by concentrating flow of energy.

Household insulation

In the residential buildings, insulation is a material which is used for preventing heat transfer. Well insulated property helps in making it energy efficient, which ultimately helps in saving money. The insulation material for residential buildings may range from the concrete block to mats of the synthetic fibers. The plastic film is used for covering the windows to preventing heat transfer any further. Insulation is usually put into walls as well as attic of the house.

1. Dimensional limits of hollow insulator

The hollow insulators made with porcelain materials C130, as single part component, dimensions according to the drawings. The possible fittings, hot dip galvanised or aluminium casting iron, connected to porcelain body with the help of Portland cementing. High resistance for bending as well as pressure loads.


For indoor as well as outdoor power equipment for being operated in the Air Conditioning system upto 100 Hz. For example disconnectpors, measuring transformers, switches, earthing switches, bushings, surge arrestors, capacitors as well as cable terminals.

1. Dimensional limits of glued hollow insulators

The hollow insulators which are made with ceramic materials C130 as multi section body well connected with gluing. Possible fittings including hot dip galvanised casting iron, aluminium, connected well with porcelain bodies with the help of sulphur or Portland cementing. High resistance to pressure loads and bending.


For indoor as well as outdoor power equipment for being operated in the air conditioning systems upto 100 Hz. For example, disconnectors, measuring transformers, earthing switches, capacitors, surge arresters, cable terminals, bushings, etc.

Hollow insulator types

The forms and types of hollow nsulators mainly depend on the requirements of the customers as well as the applications. Whether with sheds, or without sheds, the conical, cylindrical, or barrel shaped with the alternating or regular sheds, the assembling sections, gritted, flat, profiled or grooved, the surface with the needed roughness for the prupose of sealing without or with the end fittings.


For the indoor as well as outdoor power equipment for being operated in the air conditioning system, upto 100 Hz. For example, disconnectors, switches, measuring transformers, earthing switches, bushings, surge arresters, capacitors etc.

For the ceramic insulators, we make use of high strength and resistance porcelain as per the standards C130, ANSI as well as IEC. During the process of manufacturing these products are developed with the help of round bodied, cylindrical or conical inside the diameters upto the length of approximately 110.23 inch as one single unit. The benefit of hollow insulators lie in achieving a very high mechanic resistance alongwith electric insulation capabilities.

The design of a hollow insulator is affected by requirements of the customers and it mainly depends very strongly on the prevailing conditions of the future locations. On the basis of the experience as well as latest techniques of manufacturing, these insulators may even produce some unusual geometries for the ceramic hollow insulator.

  • The voltage level is 1 to 1100 KV
  • Max length of installation is 354.33 inch(with the help of adhesive technology, approximately 110.24 inches for a single unit)
  • Flexible leak path upto approximately 1.575” per kv
  • Conical design (most preferred for the process of insulation of bushings as well as dead tank circuits breaker porcelain)
  • Cylindrical design(most preferred for a live tank circuits breaker porcelain)

Method of production
  • Wet method
  • According to the standard C130, high strength aluminium porcelain
  • According to the standard C130 HS, extra high strength
  • Glaze color- brown RAL 8017 as well as Grey ANSI 70

Hollow insulators are used in the form of weather shields which help in protecting the internal components from getting exposed to vagaries of weather. They are mainly used in:

  • Voltage transformers
  • Current transformers
  • Circuit breakers – SF6 and Non-SF6
  • Capacitive voltage transformer
  • Power transformer bushing
  • Surge arresters
  • Wall through bushing

These type of insulators are of hollow construction and they are subject to the internal hoop pressure alongwith mechanical bending pressure. This signifies the importance of in design, manufacturing as well as testing of the insulators.