Having been manufacturing Weld Purging Systems since 1975 Huntingdon Fusion Techniques HFT® has evolved the science of Weld Purging for critical aerospace joints to new levels.

Along with other recently announced scientific developments in its Weld Purge Monitor® series, the Company has now reached the Fifth version of its Tube Weld Purge System designs by launching the new PurgElite® range suitable for diameters from 1” to 24” (20 mm – 610 mm) inclusive.

PurgElite® systems are particularly suitable for aerospace quality welding of tubes, pipes and cylindrical pieces where the inside of the weld is critical and must be kept free from porosity and oxidation.

This new range of weld purging systems comprises 15 models for diameters from 20 mm (0.0800”) up to 610 mm ( 24”) diameter each one overlapping the range of the other so that all internal diameters are catered for.

The system has a number of major advantages over previous weld purging systems and has taken into account the evolving technology where much higher specifications of materials and work finish are available and expected.

A. The groundbreaking key feature is the development of an in line device that issues purge gas to the inflatable dams and then releases it to purge the interspace much more quickly than ever before. This device, designated PurgeGateTM allows the operator to simply plug in the gas supply and turn on the pressure/flow.

There is no need to monitor pressure as PurgeGateTM delivers the right pressure to avoid the dams from over inflating and bursting. The operator can adjust gas flow as much as is possible without worrying about the pressure affecting the system.

PurgElite® is a simple plug and play device !Other advantages are:

1.0 The ability to manufacture a 1” system 2.0 Absence of protruding metal parts that scratch the insides of polished tubes 3.0 Elimination of the burst bladder problems that occur with other systems 4.0 Greater flexibility because the high profile valves still used by others, have been

eliminated. 5.0 Faster purging using less of the expensive inert purging gas 6.0 No complicated valve to set and to mis-function and no loss of time at the start up

of jobs.

Other features of the PurgElite® system include:

B. High Tech, high temperature resistant, synthetic gas hose C. RootGlo® Glow strip positioning band to light up the inside of dark cavities D. Selection of Low Vapour Pressure Materials

Low Profile Valve:

1” diameter tube and pipe weld purging:

For the first time it is possible to locally purge 1” diameter tube welds with an inflatable tube weld purging system, instead of having to fill up tubing assemblies with expensive inert weld purging gas.

The 1” PurgElite® Tube Weld Purging System will be a valuable welding accessory to manufacturers of many Titanium, stainless steel and Nickel Alloy tubular systems.

Absence of protruding Metal Parts:

No scratching and cross contamination:

Weld purging in the aerospace industry is mostly carried out on Titanium however, these systems are suitable when welding stainless, duplex and chrome steels as well as nickel alloys.

When internal tube and pipe surfaces are scratched by metal parts as used by old fashioned weld purging systems, there may be a loss of corrosion resistance that cannot readily be repaired and a risk of cross contamination.

Scratches cause interruptions to the flow of the gases or liquids inside and leave resting places where bacteria can multiply.

High Temperature resistant hose:

The heat build up in the welding cavity is such that the gas hose connecting the two dams has to have a high temperature resistance.

The special synthetic high temperature resistant, weld purge hose protection material is heat resistant up to 700oC (1292oF). In the event of hot liquid metal droplets falling on the hose protection, it's intumescent properties make a heat barrier to prevent damage to the purge hose, thus avoiding the risks of losing purge quality possible a weld joint.

RootGlo® Replaceable Glow Strip band:

Once PurgElite® systems are inside a tube system, they can be pulled around from joint to joint and positioned correctly and easily. This has been made possible by RootGlo® the fluorescent glow strip fitted to the centre of the purging system.

RootGlo® absorbs light while it is outside the pipe and then emits a strong glow for up to 12 hours, allowing Welders to see the centre of the purging system clearly inside dark cavities, so that they can be centered correctly.

Welders can see through a joint into the internal dark area and view the purge system as it comes into place, with the replaceable strip of RootGlo® immediately below the weld.

Low Vapour Pressure Materials:

Employing latest material developments HFT® has selected lower vapour pressure materials to ensure that the outgassing rate into the weld zone will be reduced to the barest minimum during welding to protect the molten weld pool from oxidation and the attendant problems arising.