管径 20" 18" 16" 14" 12" 10" 8" 6" 5" 4" 3" 21/2" 2" 11/2" 1" 3/4" 1/2" 20" 18" 16" 14" 12" 10" 8" 6" 5" 4" 3" 21/2" 2" 11/2" 1" 3/4" 1/2" 20" 18" 16" 14" 12" 10" 8" 6" 5" 4" 3" 21/2" 2" 11/2" 1" 3/4" 1/2" 1/2" 505 470 440 400 380 355 310 275 265 235 205 195 180 175 160 160 145 3/4" 520 485 455 415 390 365 320 290 275 250 215 205 195 190 175 170 1" 520 485 455 415 395 370 325 290 280 250 220 210 195
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