Vancouver, British Columbia, Canada
At this year’s ASME Pressure Vessels & Piping Conference, in Vancouver British Columbia, Canada, Valley Forge’s Rusty Flocken presented results from testing performed in collaboration between Valley Forge and Shell Oil Company. FEA/FFS Specialist Dr. Gong Jung with Shell directed test efforts and offered for Mr. Flocken to co-publish and present the results as part of the annual conference.
The project goal was to significantly reduce man-hours required to complete bolt-up of a flanged piping connection while at the same time, maintaining or improving the joint’s capacity for sealing. This was accomplished by selecting a tightening pattern with the fewest moves, a torque tool capable of faster, continuous tightening, along with the use of Valley Forge’s patented SPC4™ load indicating fasteners for control and monitoring of bolt load scatter.
When tightening a flanged piping connection, it is common practice to use the Legacy tightening pattern along with a cassette-type hydraulic torque wrench. This combination is one of the longest used and most widely used methods available, and therefore was used as a bench mark against which to measure improvement. To provide the greatest improvements in time-savings and bolt load scatter, a tightening system was selected using a modification of the Legacy pattern known as the Alternative #3, along with a pneumatic torque multiplier.
Results from testing show a 15% reduction in scatter, however the time taken to perform the task was reduced by approximately 63%. In addition to the direct benefits shown, if fastener load can be monitored directly and reliably on in-service joints, using load indicating fasteners or similar tension measurement method; studies similar to this one could be conducted using option 1 presented in ASME PCC-1 for developing new alternative procedures. This would allow practical, meaningful data to be collected while reducing the risk inherent with testing new assembly procedures in the field.