OSR is currently providing on-site stress relieving services to several major manufacturers of down-hole pipe. These orders consist of large quantities of pipe-joints, each up to twenty feet long, with box and pin welds and often centralizers. Because of the special material type and extremely corrosive operating conditions, these welds must be stress relieved. In order to provide the customer with the most effective and economical production, OSR has contract services that include using numerous 6-zone or 12-zone heat treating machines capable of stress relieving up to 24 welds at one time. Weld sizes can range from 2” to 12”. Outside diameter.

The two photographs show pipe joints with welds being set-up and for stress relieving. Each weld is prepared by spot-welding thermocouples in the HAZ. Specialty ceramic pad heaters are then installed over the weld are. To minimize heat loss, these heaters are then over-wrapped with high density ceramic fiber insulation. Each heater and its controlling thermocouple are then wired back to one of the OSR specialty heat treat machines via cable sets. These machines monitor, control and produce an accurate strip chart record for each set of heated welds. Ramping and holding limits of +/- 25° Fahrenheit or better are standard.