Interrupted Turning Operation Cuts Cost With 10-Sided Insert


MMS NOV image

The remanufactured blowout preventers (BOPs) are made of 4140 steel with Inconel welding seams. To machine the seams into spec, NOV used the TurnTen-Feed inserts in an interrupted turning operation.

Using a robust 10-sided insert from Tungaloy, this oil-industry remanufacturer was able to reduce the number of inserts used in interrupted turning operations.

In the wake of the Deepwater Horizon oil rig disaster in 2010, the United States imposed many new regulations on deep-ocean drilling that necessitated the regular replacement of blowout preventers (BOPs), which are designed to prevent future spills. To reduce the cost, oil companies turn to remanufacturers for getting used BOPs back up to specification. One such remanufacturer is National Oilwell Varco (NOV), an international manufacturing company dedicated to the oil industry.

To bring a BOP back up to spec, the company welds it with Inconel, then machines the seams back down. To machine off the excess material, the company performs an interrupted turning operation, slowly lowering the cutting tool to the workpiece and cutting away the irregular Inconel seam.

Unfortunately, as the cutting tool engages the seam, it undergoes tremendous strains from constantly disengaging and reengaging with the seam. The most strenuous part of a machining operation for a cutting tool is the moment it makes contact with a part, which makes interrupted turning especially damaging for cutting tools. What this meant in practical terms for NOV was a lot of damaged inserts.  READ MORE >>