Exothermic Welding

Exothermic Welding

Exothermic Welding

Exothermic Welding Process, Also known as Thermite Welding -OMEWELD

an exothermic welding mould is manufactured from high-quality graphite, accurate production and expert engineering
Earnest design: Weld capvity, flow path.

Exothermic welding is a process that bonds conductors to conductor, or conductors to steel surface together, by molecular bonding with no porosity inside weld joint. This results in excellent electrical conductivity, and superior mechanical strength in every environmental condition. The welded joint can be buried directly in soil or concrete, making it ideal for underground Electrical systems in substations and power plants, Cathodic protection for pipelines, Railway systems, Lightning protection systems, Telecommunication networks, and any installation requiring long-term reliability. Unlike mechanical connections, exothermic welds do not loosen over time and provide a service in life itself.

“Exothermic” is a chemical term used to describe a reaction that produces heat.
INTRODUCTION
Exothermic welding, also known as “thermit welding” or “aluminothermic welding” is a welding process 
for permanently joining materials (usually copper conductors) that employs an exothermic reaction. The 
exothermic reaction requires no external heat or a power source. All that is required is a spark to initiate 
the reaction.

Introduction to exothermic welding
The exothermic reaction occurs between copper oxide and aluminium powder (contained within the weld 
metal) creating molten super-heated copper and an aluminium oxide slag. When an ignition spark comes into 
contact with the weld metal, it causes an exothermic reaction within the weld metal, melting and separating 
the metals. The aluminium rises to the top of the connection creating a slag leaving the molten copper to flow around the joint, creating the weld.
The KingsWeld exothermic connection is a permanent, maintenance-free weld that will not loosen overtime 
or deteriorate with age. The connections’ current carrying capability is equal to or greater than that of the 
conductors being joined. In other words, there is no increase in resistance in an exothermically welded 
connection, unlike in most pressure type (bolt/crimp) connections.
Throughout the world, exothermic welding has been shown to be the best choice where safety, reliability, 
current carrying capacity and longevity are critical.
The advantages of exothermic welding
1 The current carrying capacity of the connection is greater than or equal to that of the conductor
2 Has a lower electrical resistance than a mechanical connection
3 Does not deteriorate with age
4 Does not loosen over time
5 Can withstand repeated high current surges without deterioration
6 Does not require an external power source
7 Used to weld copper, copper alloys, copper bonded steel, various steel alloys, including stainless steel
8 Quick and easy to install
9 Exceptional corrosion resistance due a very high copper content (97%+)
10 Fusion temperature is in excess of 2000°C forming a molecular bond
This adds up to a superior connection when compared to mechanical or pressure type (crimp) connectors.
The KingsWeld exothermic connection is the best choice, especially in safety critical environments where 
reliability, longevity and current carrying capacity are paramount

The Exothermic Welding Process is a simple, efficient method or welding Copper to Copper of Copper to Steel. One advantage is that No outside power is required when using the Exothermic Process. The exothermic process uses high temperature reaction of powdered copper oxide and aluminium. The reaction takes place in a semi-permanent graphite mold. These molds should last approximately forty or more welds if proper care is given. The reaction takes place very rapidly; threfore the total amount of heat applied to the conductors or surfaces is considerably less than that of brazing or soldering. This is important to remember when welding to insulated cable thin wall pipe.

This system is very field friendly, since its is light and portable and requires no outside power source. It requires very little time or skill to obtain an efficient, maintence free connection when using this Exothermic Welding Process.
 

The Exothermic Process has been used to weld materials other than copper for electrical purpose. Materials welded include :

Stainless Steel Copperweld Nichrome V
Galvanized Steel Silicon Bornze Copper Clad Steel
Columbium Plain Steel Everdur
Kama Steel Rail Cor-Ten
Brass Bronze Niobium
Chromax Cast Iron Monel

When welding to galvanized steel it is recommended to resurface exposed bare steel. The Exothermic Welded Connection is a molecular weld. The weld has the same melting point as copper. This factor among with the increased cross sectional area of the connection and the following insure :

1.
The Exothermic Welded connection will not be affected by a high current surge. Tests have shown that the electrical conductor will melt before the exothermic connection when subjected to high short circuit current . Consult IEEE Standard 837.
   
2. The Exothermic Welded connections will not loosen or corrode at the point of weld. There are no contact surfaces or mechanical pressures involved. An Exothermic connection becomes an integral part of the conductor.
   
3. Exothermic connections have a current carrying capacity equal to or greater than that of the conductor.
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