Long Distance Weld Purge Monitoring
Often when welding lengths of tubes and pipework fabrications of 20 metres or more, measuring the purge gas might not always easy. Under these conditions, there is a risk of contamination of the gas exiting the weld zone, leaving the welders uncertain about their welds and welding procedure.
Weld Purging Experts Huntingdon Fusion Techniques HFT® have designed and developed the PurgEye® 1000, a localised sensor with long distance cable that displays the oxygen level in the welding zone on a Weld Purge Monitor® screen that might be 10, 50 or even 1,000 metres away from the weld.
The PurgEye® 1000 comprises a stainless steel housing with a sensing head that can be fitted onto any Pipe Weld Purging System or simply left in the welding zone and have the oxygen levels transmitted electronically to a monitor up to 1 km away.
Luke Keane, Technical Sales Manager for HFT® said: “By using a remote sensing head, which can be fitted onto any Mechanical or Inflatable Tube and Pipe Weld Purging System from 1” (25 mm) diameter upwards, or even left in the welding zone, the oxygen level can then be measured directly at the weld location and the information will be electronically transferred to the monitor up to 1 km away. With this capability, the operator can be certain that the weld purge reading is correct and that the joint will not be adversely affected by oxidation.” will be welded at the correct time without any risk of contamination, oxidation or ultimate failure”
“The PurgEye® 1000 is one of our five Weld Purge Monitors® to now feature PurgeNet™, a networking device designed for communicating the current oxygen reading from the Monitor, to another piece of equipment, such as the visual warning accessory PurgeAlarm™ or a Dew Point Monitor with additional inter-pass temperature monitoring.”
The PurgEye® 1000 measures oxygen levels from 1,000 parts per million (ppm), right down to 1 ppm (accurate to 10 ppm), ideal for welding metals such as stainless steels, duplex steels, titanium and zirconium where oxide free, zero colour welds are required time after time.
Without this instrument, weld purge exhaust gas would be piped down a hose to a distant measuring instrument taking many minutes, or even hours to reach a stable reading. The exhaust gas may even be contaminated on the way, by outgassing from the walls of the hose material or from air drawn in through a leaky connection. This would cause uncertain delays in reaching correct oxygen readings that would make the process longer than necessary and could even fail to give timely changes in oxygen levels in the weld zone. In the event the oxygen level is too high, the weld would become oxidised at best and might even have nitrogen and hydrogen absorbed into the joint at worst, which could cause metallurgical defects.