Long-Distance Weld Purge Monitoring

GTA/TIG welding long pipelines made of stainless steel can be found in many different industries including oil and gas, nuclear, and liquified natural gas (LNG). The use of stainless steel can offer many advantages including corrosion-resistance and cost-effectiveness of the alloy.

With stainless steel being a reactive material, the oxygen in the protective gas must be purged down to under 100 ppm before, during, and after welding, which can cause some difficulties in long pipelines.

With a stainless steel sensing head that can be fitted onto any pipe weld purging system or left in the welding zone, the PurgEye 1000 from Huntingdon Fusion Techniques HFT (West Melbourne, FL) measures 1 parts per million (ppm) to 1,000 ppm of oxygen from a distance of 1 kilometer.

The PurgEye 1000 is one of five HFT purge monitors with PurgeNet, a networking device that communicates the oxygen reading from the monitor to another piece of equipment, such as the PurgeAlarm visual warning accessory or a dew point monitor with additional interpass temperature monitoring.

“If exhaust gas from a normal weld purge system is piped down a hose to a distant measuring instrument, it may take many minutes or even hours to reach the sensor,” says HFT Technical Sales Manager Luke Keane. “The exhaust gas may be contaminated on the way by outgassing from the walls of the hose material or from air drawn in through a leaky connection.

“The PurgEye 1000 is designed to overcome such difficulties and has a sensor placed immediately next to the weld purge site with electrical connection to monitoring equipment. Welders can be certain the reading is correct and that the joint won’t be adversely affected by oxidation, allowing them to achieve that sought-after zero-color weld without losing corrosion-resistance.”

The PurgEye 1000 measures oxygen levels, ideal for welding metals such as stainless steels, duplex steels, titanium and zirconium where oxide free, zero colour welds are required time after time.

HFT COB USA, 6909 Vickie Circle, West Melbourne, FL 32904, 321-723-3200, Fax: 321-984-8455, [email protected], www.huntingdonfusion.us.