When it comes to pipe purging, it is not desirable, nor cost effective to simply pour inert gas into the pipe assembly in the hope that a good purge is achieved. A tough, leak tight purging barrier is required.
To keep purging costs down, Weld Purging Experts, Huntingdon Fusion Techniques HFT® have designed and developed Weld Purge Film®, a water-soluble polyvinyl acetate purging barrier for a variety of pipe sizes.
Luke Keane, Technical Sales Manager for Huntingdon Fusion Techniques HFT® said: “It is so easy to cut a circle of water-soluble film and place it a short distance away from the root gap before welding, pasting in place with the Argweld® Water Soluble Super Adhesive® to ensure a tough leak tight barrier, keeping the purging volume to the barest minimum. Argweld® Weld Purge Film® offers users the opportunity to make significant economies by minimising gas usage and cutting down dramatically on time taken to make a purge, whilst at the same time, achieving a desirably low oxygen level.”
Prior to welding of titanium, widely practiced in the aerospace Industry, the oxygen content of the purge gas must be reduced to a level below 50 ppm.
Engine components such as discs, blades, shafts and casings, from the front fan to the rear of the engine, and fasteners, airframe components and landing gear are all examples where titanium is used. Further examples are fuel tanks for satellites and military jets. Components such as wing spars have also been made recently out of titanium using the Wire Arc Additive Manufacturing (WAAM) process.
The innovative PurgEye® Desk, a new monitor designed and manufactured by weld purging experts Huntingdon Fusion Techniques HFT®, is leading the way in inert gas weld purging technology by reading oxygen levels from 1,000 ppm, right down to levels as low as 1ppm (highly accurate to 10 ppm), ensuring welders achieve perfect oxide free, zero colour welds time and time again.
The Pipestoppers® Division at Huntingdon Fusion Techniques HFT® provides a cost saving solution to carrying out repairs or modifications on pipes with liquid inside, which also includes valve replacement.
Replacing valves in pipework can be a challenge, especially when the pipelines have liquids running through them. One option is to completely drain the system to make the repairs, which can prove costly, time consuming and problematical as to where to drain the liquid.
Georgia Gascoyne, CEO for HFT® said: “Qwik-Freezer™ is the industry standard portable CO2 Pipe Freezing System, in use around the World, covering pipe diameters from 3/8” – 8” (9 – 200 mm). The quick and easy to use system requires very little set-up time and is the only CO2 Pipe Freezing System capable of freezing larger pipe diameters.”
With the ever-increasing activities in such industries as the Nuclear, Oil and Gas and Engineering, there is a large volume of stainless steel, zirconium and titanium pipework that will need to be welded to a very high standard.
An effective Weld Purge Monitor® present, in conjunction with weld purging equipment when making joints will ensure engineers have an accurate oxygen reading before, during and after the welding cycle.
Huntingdon Fusion Techniques HFT® manufacture a unique, stylish, all singing and dancing Weld Purge Monitor®, the PurgEye® 600, which reads from atmospheric level of oxygen (20.94%), down to one part per million (0.0001%).
Heavy-duty leak testing, sealing, pipe blocking and stopping is easy with Steel Plugs from the Pipestoppers®.
Steel Test Plugs can be used for low pressure testing and plugging pipes, pipelines and pipework fabrications and other orifices between 2 and 48” (50 to 1,200 mm) diameter.
Luke Keane, Technical Sales Manager for HFT®’s Pipestoppers® Division said: “Plugging challenges are a thing of the past with our Steel Plugs range. They provide a strong, leak-free seal with each plug having a long life span.”
“Where plugs might be required to work close to the top of their pressure range and to hold seals longer than would be the case with single plugs, we also manufacture Double Steel Plugs, which increases the capability of the plug.”
When it comes to TIG welding, Tungsten Electrodes are the most important part of the application. A properly ground Tungsten Electrode will help to improve arc starting and stability, giving an overall better performance.
Huntingdon Fusion Techniques HFT® manufactured the TEG-1000 Tungsten Electrode Grinder with a diamond wheel, resulting in clean and smooth finishes, with no splintering and eliminating arc jumping.
Ron Sewell, Chairman for HFT® said: “Grinding Tungsten Electrodes with a dedicated Tungsten Electrode Grinder will help produce a stable arc, which then provides greater tungsten life. Grinding Tungsten Electrodes incorrectly may result in the tip being dropped into the weld pool, which may lead to weld cut-out or rejection.”
Typically for closure welds, tight bends, T piece joints and dome end connections where a conventional Tandem Weld Purging System cannot be used, a range of low cost, single ended Inflatable Weld Purge Dams is available for pipe diameters from 6 to 88 inches (150 mm up to 2,235 mm).
Weld Purge Dams from Huntingdon Fusion Techniques HFT® offer a great, lightweight solution where access is difficult, are easy to inflate and heat resistant up to 80oC (176oF).
Ron Sewell, Chairman at Huntingdon Fusion Techniques HFT® said: “Even today, many companies are still allowing their technicians to spend many hours fabricating dams made of foam, cardboard, adhesive tape, wood and so on. Like paper, these materials contain a high percentage of water, which is very undesirable to have in the presence of a weld.
Ceramic Backing Tape is often used to help support weld roots. However, with a melting point of 1,800ºC, concerns grow during TIG welding, where temperatures can reach up to 6,000ºC.
Leaders in Weld Purging Technology, Huntingdon Fusion Techniques HFT® manufacture a range of Weld Backing Tape®, with no true melting point, helping to support weld roots and prevent ‘sugaring’ or ‘grapes’.
Luke Keane®, Technical Sales Manager for Huntingdon Fusion Techniques HFT® said: “Achieving clean welds is easy with Argweld® Weld Backing Tape® available up to 600 amps. Weld Backing Tape® with help protect and support the backside or under side of the joint during welding.”
Weld Purging is the act of removing oxygen from the vicinity of a weld, before, during and after welding reactive metals by displacing the oxygen with an inert gas (usually argon).
When welding stainless steel, the oxygen level must be reduced to a required minimum, which is less than 100 ppm.
The most effective way to know the oxygen level is to measure it with a Weld Purge Monitor®. Leading the way in Weld Purging Monitoring Technology, Huntingdon Fusion Techniques HFT®’s PurgEye® 100 is perfect for obtaining oxide free welds in stainless steel, reading accurately from atmospheric oxygen level (20.94%), right down to 100 ppm (0.01%).
Ron Sewell, Chairman for HFT® said: “It is important not to use alternative low cost oxygen analyzers or other oxygen safety monitors as they are calibrated under ambient conditions and therefore unsuitable for measuring purge levels down to 0.01% as our Award Winning PurgEye® 100 does.”
Inflatable Tube and Pipe Purging Systems simplify the process of inert gas purging by restricting weld purge volumes, making huge savings in time and inert gas.
Huntingdon Fusion Techniques HFT® design and manufacture PurgElite®, a range of low cost Tube and Pipe Purging Systems that help to achieve a clean, oxide free, zero colour weld in just minutes, available from 1” (25 mm).
Ron Sewell, Chairman for HFT® said: “Purging a pipe prior to welding is critical to the success of welding stainless steel, titanium, zirconium and other reactive alloys. PurgElite® systems are simply inserted in the pipe and positioned with the aid of the luminous RootGlo®. When the gas flow is started, the dams inflate, sealing inside the pipe and argon then purges the interspace automatically. A Weld Purge Monitor® connection is standard on each PurgElite®, so the welder can monitor the oxygen content of the purge volume throughout the entire welding process.”