Generally, before tubes are threaded, a hot forge process is applied to each end to increase the wall thickness.
This upset process allows the pipe to maintain consistent strength throughout the tube and the added wall thickness is required for threading. Sim-Tex offers tubing with standard API upsets or selected premium upsets.
Pipe upsetting is a process that is applied to the ends of the tubing product to allow the pipe to be threaded. The pipe upsetting process is accomplished by heating the ends of the tubing in the upset furnace after which, the heated tube end is put into the upsetter. The tube is held in place by two dyes, and the upsetter forces the punch into end of the heated tube, creating the upset. The pipe is then air-cooled and any metal flashings on the upset are removed with a grinding machine. The upset end of the tube is visually inspected on the outside diameter (OD) and internal diameter (ID) to ensure there are no wrinkles or underfill. After passing visual inspection, the pipe is then hot drift inspected to ensure the ID of the pipe has not changed significantly during the upsetting process.
The upsetting process allows the pipe to maintain consistent strength throughout the tube and the added wall thickness is required for threading. Sim-Tex offers tubing with standard API upsetting or selected premium upsetting. Sim-Tex personnel monitor our upset processors to ensure API standards are maintained and require the processors to rework any pipe upsetting which fails to meet API standards.