Continuous rolling tube (hereinafter referred to as MPM) process is a mandrel refers to wear long capillary column continuously through a series arrangement rack, rolling and rolling method conforms to become rolling mother pipe size requirements. Its distinguishing feature is the large capacity, high efficiency, good rolling blank pipe length and product quality, large size range; but its large investment and related technology and automatic control more demanding.


MPM rack for the two-roll type, structure substantially similar to common double rolling mill. Depending on the movement of the mandrel MPM can be divided into full-floating and semi stopper stopper mandrel mill three types.


1970s before MPM use a full-floating mandrel operation. From punch to penetrate capillary after the mandrel into the pipe rolling machine rolling, rolling when the rolling out of the mill is the background to pull back to the mandrel rollers, there are bar off the machine from rolling mandrel member is withdrawn, rolling into the next step, and returned to the mandrel mill reception after cooling, re-enter the next cycle of work.


1970s France and Italy have appeared in the mandrel half stopper and stopper of MPM. In essence, these two methods of operation on the mandrel tube rolling machine, are borrowed from the mandrel method of operation of the three-roll rolling machine.
Half retained mandrel method of operation, is in the process of rolling, the mandrel movement speed is limited, the card holder mandrel is clamped to less than rolled forward speed of the workpiece. Retained mandrel method of operation, except during rolling, the mandrel movement speed is limited, the tie finished after rolling, the mandrel by the card holder towed back to work starting position.


In recent years, the Y-shaped three-roll MPM characterized PQF mill, followed the tension-reducing technology from the second roller to three roller changes, so rolling process rolling deformation conditions of stress and deformation distribution, machinery, electrical appliances load distribution, rolling wall thickness and wall thickness tolerances and so has a two-roll mill unmatched advantages. Its stable rolling process can be improved pipe cross-sectional dimension, lower flange area or crack Lin Wen phenomenon in the field of thin-walled pipes and rolling high alloy pipe more adaptable and economy.