These Pin Insulators are made by the wet process using high grade raw materials. The basic raw materials that go into the manufacture of these insulators of these insulators are naturally occuring clays and minerals like quartz and feldspar. The coarsely-powdered materials are ground to the required particle size in ball mills. The moisture content is reduced in filter process to obtain solid cakes. The cakes are fed into the pug mills. The void free pugs that are extruded from the pug mills are then pressed into shape and glazed after drying. These insulators which are thoroughly inspected before glazing are fired in the tunnel kilns.

The body composition developed over the years ensures excellent mechanical and electrical characteristics. These insulators are provided with Zinc thimbles suitable for Small and Large Steel Head Pins. Above Pin Insulators are subjected to a full series of type tests such as Impulse and Power Frequency Tests, Temperature Cycle Test, Mechanical (cantilever) test, Puncture Test & Porosity Test. Full quality control is exercised at all stages of manufacture. Some of the tests conducted on all insulators during manufacture are crack detection before firing, high frequency high voltage test besides routine electrical test at power frequency, in addition, porosity and temperature cycle tests are conducted for each batch of manufacture.


These pin insulators conforms to specifications, BS:137, IEC:383, IS:731 and other international specifications.

Standard Particulars
Product No. UT-P2212 UT-P3311 UT-P3312
Highest System Voltage kV 24 36 36
Total Creepage Distance (Nominal) mm 432 580 685
Protected Creepage Distance (Nominal) mm 210 300 335
Cantilever Strength kN 10 10 10
Flashover Voltage Power Frequency Dry kV 100 110 130
Wet kV 60 85 95
Impulse Positive kVp 160 205 210
Negative kVp 205 225 250
Withstand Voltage Power Frequency Dry kV 90 100 110
Wet kV 55 80 90
Impulse Positive kVp 140 180 200
Negative kVp 150 190 220
Power Frequency Puncture Voltage kV 145 200 210
Visible Discharge Voltage kV 18 27 27
Thimble Type : IS:2486 (Part-II)/ BS:3288 (Part-II) Large Large Large
Nett Weight (Approx.) kg 5 7.5 9.5
Contents of each package Nos 4 3 3

Applicable Specifications IS:731 BS:137 & IEC:383
Note : Insulators can also be supplied with Radio Free Glaze.


Export packing of insulators in pallets