NOMINAL PIPE SIZE PRESSURE CLASSES
API 6BX
2000# 3000# 5000# 10000# 15000# 20000#
1 11/16" - - - BX-150 BX-150 -
1 13/16" - - - BX-151 BX-151 BX-151
2 1/16" - - - BX-152 BX-152 BX-152
2 9/16" - - - BX-153 BX-153 BX-153
3 1/16" - - - BX-154 BX-154 BX-154
4 1/16" - - - BX-155 BX-155 BX-155
5 1/8" - - - BX-169 - -
6 5/8" - - - BX-170 BX-170 -
7 1/16" - - - BX-156 BX-156 BX-156
8 9/16" - - - BX-171 BX-171 -
9" - - - BX-157 BX-157 BX-157
11" - - - BX-158 BX-158 BX-158
11 5/32" - - - BX-172 BX-172 -
13 5/8" - - BX-160 BX-159 BX-159 BX-159
16 3/4" - - BX-161       BX-162  BX-162 BX-162 -
18 3/4" - - BX-163 BX-164 BX-164 -
21 1/4" - - BX-165 BX-166 - -
26 3/4" BX-167 BX-168 - - - -
30" BX-303 BX-303 - - - -