Dielve from Italy

By James Mulvey; posted September 17, 2012

View Original (500 x 491) 38KB


It's been a long road full of twists and turns and disapointments, but I finally added a seven inch fog type glass suspension to my display. Over the last few years I have found several for sale in Italy. I have purchased items from many overseas countries over the last 15 years and I can't recall any diffuculties or disapointments. Italy is the exception. Well, not exactly an exception but the exact opposite. I can't recall a single transaction from Italy that I was satisfied with. The first Italian ebayer I purchased an insulator from, XXXXX, switched it for one with a 3 inch crack and illegilable embossing.( His antics on eBay since then have confirmed that this was not an accidental mixup) Between that deal and this last purchase there were several sellers who seem to think that sea-mail postage for a single 6 inch glass disc should be - are you ready for this, the cheapest quote was 160 and the highest was 200 euro ($200 - 250 USD). These rates were from different sellers. Before I knew better, I directed one seller to XXXXX who was regularly shipping insulators to USA for $10-12. The insulator I was after was listed on eBay for 5 euro + 160 euro postage. I suggested he contact XXXXX to find out what service he used. Later, the reply I got was that he could ship me the insulator for 65 euro but now wanted 60 euro for the insulator ! That was a couple years ago. Recently I came across his recent relisting for that very disc, still listed but now reduced to 40 euro.............. I do wonder what conspiracy transpired between them, but only for a moment. A second seller wanted 185 euro to send a similar disc to me. By this time I had checked with a couple Iconers who were buying insulators from Italy, as well I asked Nora, and all believed that 20 euro was more than enough. This ebayer had listed her insulator for 1 euro. I offered her 25 euro for the insulator including the shipping. I received an immediate reply, all in caps. It did not translate well but I believe she was directing me to do something physically impossible. After that another seller quoted 200 euro - so I gave up all attempts to buy from Italy. Since then postage rates have undoubtly increased .

It had bugged me since I had assembled the display that that disc was missing. It was as they say the proverbial missing link in a string I was working on. A couple years have gone by. It was quite by chance that I happened to find this Dielve disc listed. Since I had not even heard of or owned one, in a weak moment I inquired about shipping. Even with the increased rates, the cost of the insulator and a $ bonus to the seller. 27 euro got it here.

Dielve has an informative website. Some of their info. I have added below. In their manufacturing lineup they have a 17 inch open profile, aerodynamic glass plate suspension. Hmm, I wonder what the minimum order is. http://www.dielve.com/Dielve/enprod.html

Dielve is a leading manufacturer of Toughened Glass Insulators for high voltage transmission lines. We established Dielve as a Limited Company in 1986 and built a completely new production factory at Nusco ( approximately 120 km east of Naples, in southern Italy ). The factory started production in 1989 and naturally our first client was ENEL, the Italian National Electrical Company. In the first ten years of operation, Dielve sold more than 14 million insulators to more than 80 different countries worldwide, including, besides Italy, France, Vietnam, United Kingdom, Spain, Mexico, Thailand, New Zealand, South Africa, Iran, Lebanon, Turkey, Chile, Malaysia, Peru, Finland, Ireland, Norway, Brazil and many more. We only manufacture high voltage insulators, of which at least 80% represent the cap and pin type suspension insulators. The remainder are rigid pin type distribution insulators and lightning arrestors. The rated tensile strengths of our insulators range from 40 kN to 300 kN in both plain and fog types. They are used in all parts of the world, from temperate England to tropical Brazil, from glacial Iceland and Norway to hot desert lands such as Algeria. Although the vast majority of our insulators is designed and manufactured to the relevant IEC standard, we also supply in accordance with standards such as ANSI and other National Standards. At present, approximately 80% of our annual sales are exported. Speaking only of first­class toughened glass insulators, our market share is approximately 17% of the worldwide market. In 1993 we were the first glass insulator manufacturer to receive certification to ISO 9001. We carry out our own research and development as well as the conception and engineering of new products and new process equipment. The technology we use in our factory is entirely our own, not having made recourse to any licensing agreement. We have been responsible for the design, development, testing and commissioning of all the insulators included in our range. In addition, all key manufacturing equipment is Dielveís own conception and design, and has been built under Dielveís direct control. Our laboratory is equipped to perform all the tests on single units required by international standards. Almost all the type tests relevant to our insulators have been performed in prestigious international independent laboratories. Among these are CESI in Italy, KEMA in The Netherlands, the Ontario Hydro Laboratory in Toronto, Canada and the EDF Laboratory in France. All the production of the Dielve insulators is carried out in our Nusco factory. The glass shells are made there and are assembled with metal parts purchased from the leading specialized manufacturers in the world. The whole glass shell manufacture is completely automated and computer controlled. There is no direct human intervention from the stockpiling of the raw materials up to the visual inspection before assembling the insulators. All our work is to the requirements of ISO 9001. All the manufacturing operations are in accordance with our Quality Manual which also defines the requirements for product identification and traceability.

Description of the Glass Manufacturing Process

All of the batch preparation is controlled and operated by computer. According to the specified formula for preparation of the batch, the weighing of the mix of the raw materials with a predetermined quantity of cullet is automatically done on electronic scales under computer control. The cullet is the only raw material we do not buy. We produce all our cullet requirements, either as recovery of insulator shells rejected by quality control, or as surplus production of the smaller insulators. When the stock of cullet is not sufficient, we may even purposely produce cullet only. We never buy cullet from external sources because we want to maintain total control on the quality of the materials we charge into the oven. The batch melting takes place in an electrical oven. With such an oven, having no exhaust from a chimney, we control the oxide inclusions in the glass with a far higher precision than is possible with combustion ovens. The characteristics of an electrical oven ensure a high level of glass consistency and homogeneity. Moreover, an electrical oven provides for the lowest environmental impact because there is no polluting smoke discharge from the chimney into the atmosphere. Molybdenum electrodes are completely immersed in the bath of molten glass. The raw material is poured onto the surface of the bath in such a way as to form a layer approximately 300 mm thick, that floats on the molten liquid glass and therefore acts as an insulating screen, thus keeping the oven vault temperature at approximately 100°C. This categorically rules out any fragments from the vault falling into the glass. Fragments from the vault would seriously pollute the glass, and are a possible extremely dangerous phenomenon which may occur in combustion ovens due to the high vault temperature ( 1500°C ). After the molten glass leaves the oven it is conveyed to the production machines through conditioning channels. The thermal conditioning is necessary so that the glass arrives at the molding or pressing machine at the desired temperature. The conditioning channels are divided into zones, each one subject to an individual automatic temperature control, so to optimize the conditions in which the liquid glass drop is formed. This system allows a very close control of the drop weight. The printing press has been completely conceived and built by Dielve using the most modern electronics available. These allow a complete control of each phase of the glass pressing. All the system is computer operated and is equipped with internal and external diagnostics to detect any malfunctioning, which is recorded and printed for statistical purposes. A particular feature of the system is the ability to change the molds, in case of need, without stopping the machine ( and thus without losing the thermal regime ). The production line can manufacture insulators up to an external diameter above 450 mm. The toughening process is carried out mechanically by blowing compressed air in a rotary machine. The air pressure is separately controlled both in the upper and lower blowing outlets. This ensures a uniform consistency of the toughening level throughout all the production. After toughening all the toughened shells pass through a thermal shock line, in accordance with the international standards. This eliminates all the shells that might not have been satisfactorily toughened. The thermal shock temperature is prudentially kept higher than that specified by the international standards, and is maintained at the desired value by an automatic control system. The thermal shock line consists of a 35 m long conveyor running from the exit of the toughening press to the visual inspection station at the end. At the end of the thermal shock section, specialized operators make a visual inspection of all the shells.

Description of the Insulator Assembly Process

The assembly lines for cap and pin insulators each have a maximum production capacity of up to 12,000 insulators per day depending on the insulator size. One of them is entirely operated by a central computer, controlling the following operations:

Automatic pin insertion into each shell. Automatic loading onto the conveyor of the caps arriving from the automatic flocking machine. Automatic cement dosing into the cap and into the glass shell. Automatic positioning of the glass shell with its cap and pin and transfer to the vibrating assembly machine. After the cement curing in water, automatic routine mechanical tensile test and 100% automatic spacing measurement and recording. If the spacing dimension is correct, this same machine automatically inserts and opens the security clip. Automatic transfer from the tensile test machine onto the washing machine belt and then to the packing station