Session: CT-01-02 Design and Analysis of Bolted Flange Joints-2

Paper Number: 154072

154072 - Calibration and Verification of Common Tooling 

Abstract: 

Proper torque application by tools is critical for achieving target axial loads in bolted flange joint applications. This study builds on previously published papers by investigating the accuracy and repeatability of three types of torque wrenches (manual click-type, hydraulic low-profile, and battery-powered pistol grip) commonly used in bolted flange joint assemblies. The authors conducted comprehensive testing on over 400 studs across five distinct flange configurations, utilizing Ultrasonic Bolt Measurement for precise evaluations.

Our findings reveal that hydraulic torque wrenches exhibit the highest accuracy, consistently achieving target torque values within ±3%, followed closely by manual torque wrenches, which maintained an accuracy within ±5%. In contrast, battery-powered wrenches displayed significant variability, with inaccuracies averaging ±5.5%.

The study also highlights the significant role of operator skill in the performance of manual tools, suggesting that effective training is essential for maximizing accuracy. While hydraulic wrenches proved superior in repeatability, the faster torque application of battery-powered tools led to greater scatter in results.

Overall, this research underscores the importance of proper tool verification and selection in achieving reliable bolted joint assembly outcomes. It demonstrates that tooling can contribute to an accuracy variance of up to ±38% under field conditions. The data presented offers valuable insights for industry practitioners in choosing effective torque application methods.

Presenting Author: Scott Hamilton VSP Technologies

Presenting Author Biography: Scott Hamilton has been in the industry for the last 20 years researching, training, and consulting on bolted flange joint reliability. He has been the chair of PCC-1 and is currently a voting member.

Authors:

Barrett Meigs VSP Technologies
Scott Hamilton VSP Technologies
James Province Houston Fastener
Brad Tinney Houston Fastener