07837880027 Commercial Pipe Fusion Welding EN11 Cockfosters EN6 Cheshunt EN2 Broxbourne EN10 Gas Pipe Welders EN4 Ponders End EN3
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- Category: Gas Pipe Plumbing Pipe Welders
Types of fusion welding include :
Arc welding is a type of welding that uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct (DC) or alternating (AC) current, and consumable or non-consumable electrodes. The welding region is usually protected by some type of shielding gas, vapor, and/or slag.
Oxy-fuel welding (commonly called oxyacetylene welding, oxy welding, or gas welding and oxy-fuel cutting are processes that use fuel gases and oxygen to weld and cut metals, respectively. Oxy-fuel is one of the oldest welding processes. Still used in industry, in recent decades it has been less widely utilized in industrial applications as other specifically devised technologies have been adopted. It is still widely used for welding pipes and tubes, as well as repair work. It is also frequently well-suited, and favored, for fabricating some types of metal-based artwork.
In oxy-fuel welding, a welding torch is used to weld metals. Welding metal results when two pieces are heated to a temperature that produces a shared pool of molten metal. The molten pool is generally supplied with additional metal called filler. Filler material depends upon the metals to be welded.
In oxy-fuel cutting, a torch is used to heat metal to its kindling temperature. A stream of oxygen is then trained on the metal, burning it into a metal oxide that flows out of the kerf as slag.
Torches that do not mix fuel with oxygen (combining, instead, atmospheric air) are not considered oxy-fuel torches and can typically be identified by a single tank (Oxy-fuel cutting requires two isolated supplies, fuel and oxygen). Most metals cannot be melted with a single-tank torch. As such, single-tank torches are typically used only for soldering and brazing, rather than welding.
Electric resistance welding (ERW) refers to a group of welding processes such as spot and seam welding that produce coalescence of faying surfaces where heat to form the weld is generated by the electrical resistance of material vs the time and the force used to hold the materials together during welding. Some factors influencing heat or welding temperatures are the proportions of the workpieces, the coating or the lack of coating, the electrode materials, electrode geometry, electrode pressing force, weld current and weld time. Small pools of molten metal are formed at the point of most electrical resistance (the connecting surfaces) as a high current (100–100,000 A) is passed through the metal. In general, resistance welding methods are efficient and cause little pollution, but their applications are limited to relatively thin materials and the equipment cost can be high (although in production situations the cost per weld may be as low as $0.04 USD per weld depending on application and manufacturing rate).
Laser beam welding (LBW) is a welding technique used to join multiple pieces of metal through the use of a laser. The beam provides a concentrated heat source, allowing for narrow, deep welds and high welding rates. The process is frequently used in high volume applications, such as in the automotive industry.
Like electron beam welding (EBW), laser beam welding has high power density (on the order of 1 MW/cm2) resulting in small heat-affected zones and high heating and cooling rates. The spot size of the laser can vary between 0.2 mm and 13 mm, though only smaller sizes are used for welding. The depth of penetration is proportional to the amount of power supplied, but is also dependent on the location of the focal point: penetration is maximized when the focal point is slightly below the surface of the workpiece.
A continuous or pulsed laser beam may be used depending upon the application. Milliseconds long pulses are used to weld thin materials such as razor blades while continuous laser systems are employed for deep welds.
LBW is a versatile process, capable of welding carbon steels, HSLA steels, stainless steel, aluminum, and titanium. Due to high cooling rates, cracking is a concern when welding high-carbon steels. The weld quality is high, similar to that of electron beam welding. The speed of welding is proportional to the amount of power supplied but also depends on the type and thickness of the workpieces. The high power capability of gas lasers make them especially suitable for high volume applications. LBW is particularly dominant in the automotive industry.
Electron beam welding (EBW) is a fusion welding process in which a beam of high-velocity electrons is applied to the materials being joined. The workpieces melt as the kinetic energy of the electrons is transformed into heat upon impact, and the filler metal, if used, also melts to form part of the weld. The welding is often done in conditions of a vacuum to prevent dissipation of the electron beam. German physicist Karl-Heinz Steigerwald, who was at the time working on various electron beam applications, perceived and developed the first practical electron beam welding machine which began operation in 1958.
It is well known that electrons are elementary particles possessing the mass m = 9.1E10-31 kg and negative electrical charge e = 1.6E10-19 C. They exist either bound to an atomic nucleus, as conduction electrons in the atomic lattice of metals, or free electrons in vacuum.
The free electrons in vacuum can be accelerated and their orbits controlled by electric and magnetic fields. In this way we can form narrow beams of electrons carrying high kinetic energy, which at collisions with atoms in solids transform their kinetic energy into heat. Thanks to some specific conditions, this way of heating gives us exceptional possibilities.
Exothermic welding, also known as exothermic bonding, thermite welding (TW), and thermit welding, is a welding process for joining two electrical conductors, that employs superheated copper alloy to permanently join the conductors. The process employs an exothermic reaction of a copper thermite composition to heat the copper, and requires no external source of heat or current. The chemical reaction that produces the heat is an aluminothermic reaction between aluminium powder and a metal oxide.
The reaction reaches very high temperatures, depending on the metal oxide used. The reactants are usually supplied in the form of powders, with the reaction triggered using a spark from a flint lighter. The activation energy for this reaction is very high however, and initiation requires either the use of a "booster" material such as powdered magnesium metal or a very hot flame source. The aluminium oxide slag that it produces is discarded.
When welding copper conductors, the process employs a semi-permanent graphite crucible mould, in which the molten copper, produced by the reaction, flows through the mould and over and around the conductors to be welded, forming an electrically conductive weld between them. When the copper cools, the mould is either broken off or left in place.Alternatively, hand-held graphite crucibles can be used. The advantages of these crucibles include portability, lower cost (because they can be reused), and flexibility, especially in field applications.
The weld formed has higher mechanical strength than other forms of weld, and excellent corrosion resistance. It is also highly stable when subject to repeated short-circuit pulses, and does not suffer from increased electrical resistance over the lifetime of the installation. However, the process is costly relative to other welding processes, requires a supply of replaceable moulds, suffers from a lack of repeatability, and can be impeded by wet conditions or bad weather (when performed outdoors).
Exothermic welding is usually used for welding copper conductors but is suitable for welding a wide range of metals, including stainless steel, cast iron, common steel, brass, bronze, and Monel. It is especially useful for joining dissimilar metals.
North West London : NW1 covers the Camden Town, Regent's Park, Chalk Farm North, Chalk Farm Road north Marylebone area, Euston NW1 Euston Square , Regents Park NW1 Somers Town , St. Pancras NW1 Lisson Grove, NW2 Cricklewood, Neasden (also covers Dollis Hill), NW2 Dollis Hill ,NW2 Willesden Green , NW2 Neasden , Fortune Green NW3 Primrose Hill , NW3 Hampstead , Hampstead Heath, Finchley Road ,NW3 Fenton Ho. NW3 Hampstead, Swiss Cottage , Kenwood House, Belsize Park), NW4 Hendon, Brent Cross,NW4 Brent Cross , NW4 Hendon NW4 Holders Hill , NW4 Great North Way , Kentish Town NW5 Gospel Oak , NW6 South Hampstead , North Acton , NW5 Kentish Town, NW6 Kilburn, NW6 North End , Kilburn Park ,NW6 Brondesbury , NW6 Queen's Park , NW6 West Hampstead , Kilburn, Queens Park (also covers South & West Hampstead, Brondesbury Park, NW7 Mill Hill, NW7 Copthall ,NW7 Mill Hill East , Mill Hill NW7 Highwood Hill , NW7 Abbey Road ,NW8 St.John's Wood, NW9 The Hyde, NW9 West Hendon , NW9 Colindale NW9 Edgware Road ,NW9 , Kingsbury NW10 NW8 St John's Wood, NW9 The Hyde , Kingsbury & Colindale, NW10 Willesden , NW11 Harlesden , NW10 Kensal Green, Kensal Rise NW10 Lower Place, Old Oak Common NW10 Park Royal , Stonebridge NW10 Stonebridge Park , NW10 Willesden Junction , Willesden NW11 Golders Hill Park , NW11 Golders Green , NW11 Friern Barnet , NW11 Hampstead Garden Suburb ,Harlesden & Kensal Green, NW11 Golders Green , western part of Hampstead Garden Suburb,Enfield : EN1 Bush Hill Park; eastern parts of Bulls Cross, Enfield Town, Forty Hill, outskirts of Lower Edmonton, EN2 Botany Bay, Clay Hill, Crews Hill; western parts of Bulls Cross, Enfield Chase, EN2 Enfield Town, Forty Hill , EN3 Enfield Highway, Enfield Island Village, Enfield Lock, Enfield Wash, Ponders End , EN4 Barnet, Hadley Wood, Cockfosters, East Barnet, New Barnet Enfield, Barnet , EN5 High Barnet, Arkley Barnet , EN6 Potters Bar, South Mimms, Cuffley, Northaw Hertsmere, Welwyn Hatfield , EN7 Waltham Cross Broxbourne , EN8 Waltham Cross, Cheshunt Broxbourne, Enfield , EN9 Waltham Abbey Epping Forest , EN10 Broxbourne , EN10 Broxbourne , EN11 Hoddesdon, Harrow : HA0 Wembley , Alperton, Sudbury, Sudbury Hill, Wembley Central and North Wembley Brent, Harrow , HA1 Harrow, Harrow on the Hill, North Harrow, Northwick Park Harrow , HA2 North Harrow, South Harrow, Rayners Lane , HA3 Harrow Weald, Kenton, Wealdstone, Belmont , Harrow, Brent , HA4 Ruislip Hillingdon , HA5 Pinner, Eastcote, Hatch End, Rayners Lane , Carpenders Park , Harrow, Hillingdon, Three Rivers , HA6 Northwood, Moor Park, Sandy Lodge Hillingdon, , HA7 Stanmore, Belmont , HA8 Edgware, Canons Park, Queensbury Barnet, Brent, Harrow , HA9 Wembley, Wembley Park, Wembley Central (East), Preston, Essex & East London Areas : RM1 Romford Havering , RM2 Romford , Gidea Park, Heath Park Havering,RM3 Romford, Harold Wood, Harold Hill, Noak Hill Havering , RM4 Romford, Havering-atte-Bower, Abridge, Stapleford Abbotts, Noak Hill, Navestock, Stapleford Tawney, Stapleford Aerodrome Havering, Epping Forest, Brentwood , RM5 Romford, Collier Row Havering, Redbridge , RM6 Romford Chadwell Heath, Marks Gate, Little Heath Barking and Dagenham, Redbridge, Havering , RM7 Romford Rush Green, Mawneys, Romford Havering , RM8 Dagenham, Becontree Heath Barking and Dagenham, Redbridge , RM9 Dagenham, Becontree Barking and Dagenham, Redbridge, Havering , RM10 Dagenham Barking and Dagenham , RM11 Hornchurch, Emerson Park, Ardleigh Green Havering , RM12 Hornchurch, Elm Park Havering , RM13 RAINHAM Rainham, South Hornchurch, Wennington Havering , RM14 Upminster, Cranham, North Ockendon, Bulphan Havering, Thurrock , RM15 South Ockendon, Aveley Thurrock, Havering , RM16 Grays Chafford Hundred, Chadwell St Mary, North Stifford, Orsett Thurrock , RM17 Grays, Badgers Dene Thurrock , RM18 Tilbury, East Tilbury, West Tilbury Thurrock , RM19 Purfleet Thurrock , RM20 GRAYS West Thurrock, South Stifford Thurrock, IG1 Ilford Redbridge , IG2 Ilford , Gants Hill, Newbury Park Redbridge , IG3 Ilford , Seven Kings, Goodmayes Redbridge , IG4 Ilford , Redbridge Redbridge , IG5 Ilford, Clayhall Redbridge , IG6 Ilford, Barkingside, Hainault Redbridge , IG7 Chigwell, Epping Forest, Redbridge , IG8 Woodford Green, Woodford Bridge Redbridge, Waltham Forest , IG9 Buckhurst Hill Epping Forest , IG10 Loughton, High Beach (part) Epping Forest , IG11 Barking Barking and Dagenham Central London, West End London, South West London, North London, North West London, South East London, East London, Essex, Enfield, Kent, Enfield, Richmond & Twickenham, Southend On Sea
