Abstract: The paper covers an introduction about the NEL system mounted on the Assel pipe mill located at the φ170 mm Seamless Steel Tube Mill Plant,Daye Steel Works,including mainly the structure and features of the system,pointing out that with the NEL system the chronic problem of “rear triangle” bothering light wall pipe rolling with three-high mill has been almost completely solved thanks to pre-rolling.Also presented in the paper is an discussion with respect to certain parameters concerning the pre-rolling pass such as roll number and the decline angle,etc.