TY - GEN
T1 - Effects of scatter in axial bolt force on the sealing performance of pipe flange connections at elevated temperature
AU - Sawa, Toshiyuki
AU - Omiya, Yuya
AU - Takagi, Yoshio
AU - Torii, Hiroyasu
PY - 2010/6/8
Y1 - 2010/6/8
N2 - Since scatter in axial bolt force exists in assembling pipe flange connections, it is important to evaluate the effect of scatter in axial bolt force on the sealing performance of pipe flange connection. The FE and experimental analyses were done to evaluate the effect of scatter in axial bolt force on the sealing performance of pipe flange connections with 3″ (NPS 3″) and 20″ (NPS 20″) nominal diameters. The axial bolt force was measured with strain gauges mounted on the shank of each bolt. The two kinds of torque controlled assembly procedures, ASME PCC-1 procedure and JIS 2251 procedure, were evaluated as an assembling procedure and compared the scatter in axial bolt force with that of the uniform axial bolt force condition. The results revealed that the significant difference was not observed between ASME PCC-1 and JIS 2251 procedures. The scatter in axial bolt force were not changed at elevated temperature, however, the axial bolt force increased when increasing the temperature. Therefore, the tightness of the flanged connection is improved with increasing the temperature up to 200 °C. The assembly efficiency was evaluated with the experimental results of 20″ nominal diameter leakage tests and FE analyses. In addition to the scatter in the assembly axial bolt force, the flange rotation affected the axial bolt force when internally pressurized. As a result, the tightness parameter, Tp, was slightly lower than that evaluated with the assembly efficiency, η=0.85, defined in ASME PCC-1 procedure. The results are discussed and a modified assembly efficiency is proposed.
AB - Since scatter in axial bolt force exists in assembling pipe flange connections, it is important to evaluate the effect of scatter in axial bolt force on the sealing performance of pipe flange connection. The FE and experimental analyses were done to evaluate the effect of scatter in axial bolt force on the sealing performance of pipe flange connections with 3″ (NPS 3″) and 20″ (NPS 20″) nominal diameters. The axial bolt force was measured with strain gauges mounted on the shank of each bolt. The two kinds of torque controlled assembly procedures, ASME PCC-1 procedure and JIS 2251 procedure, were evaluated as an assembling procedure and compared the scatter in axial bolt force with that of the uniform axial bolt force condition. The results revealed that the significant difference was not observed between ASME PCC-1 and JIS 2251 procedures. The scatter in axial bolt force were not changed at elevated temperature, however, the axial bolt force increased when increasing the temperature. Therefore, the tightness of the flanged connection is improved with increasing the temperature up to 200 °C. The assembly efficiency was evaluated with the experimental results of 20″ nominal diameter leakage tests and FE analyses. In addition to the scatter in the assembly axial bolt force, the flange rotation affected the axial bolt force when internally pressurized. As a result, the tightness parameter, Tp, was slightly lower than that evaluated with the assembly efficiency, η=0.85, defined in ASME PCC-1 procedure. The results are discussed and a modified assembly efficiency is proposed.
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U2 - 10.1115/PVP2009-77493
DO - 10.1115/PVP2009-77493
M3 - Conference contribution
AN - SCOPUS:77953077406
SN - 9780791843659
T3 - American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
SP - 139
EP - 147
BT - Proceedings of the ASME Pressure Vessels and Piping Conference 2009
T2 - 2009 ASME Pressure Vessels and Piping Conference, PVP 2009
Y2 - 26 July 2009 through 30 July 2009
ER -