Production of Hi-precision,Small-sized and Light-wall Pipes with Φ114 mm CPE Pipe Rolling Plant

Described in the paper are the process scheme and control measures for production of the Φ89 mm× 3.2 mm and Φ108 mm×3.5 mm hi-precision，small-sized and light-wall pipes with D/S>27 with the Φ114 mm CPE hot-rolling pipe mill.Also analyzed are the control difficulties and key points concerning the production activities. Result of the trial production demonstrates that the preconditions for guaranteeing the finished product dimensions are to get the pierced shell WT deviation within 7%，and properly control the longitudinal WT fluctuation during the push bench process，and that it is practical to use the hot-rolling process to produce the hi-precision，small-sized and light-wall pipe with D/S>27，allowable OD tolerance D as（-0.5%～+0.5%）and allowable WT tolerance S as（-9%～+9%）.