Downstream equipment of pipe production line is composed of three processes: 1) cooling/sizing with help of Vacuum Sizing Machine, 2) Pulling through tractor, 3) Cutting/coiling/takeoff. JINHU vacuum sizing machine is made by stainless steel fixed with vacuum system and water circulating system for shaping and cooling. The proper dimensions of pipe are maintained by the sizing operation when cooling of the molten material is being processed. Basic operations in vacuum sizing machine are:

• Molten extrudate from extruder drawn into the first vacuum chamber through calibration or sizing tool.
• After that, vacuum forces the plastic against the sizing or calibration tool while its surface is cooled enough to maintain proper dimensions. Cooling water enters the chamber through the spray bars.
• The sized and calibrated plastic is pulled through a second vacuum tank or series of spray or immersion cooling tanks, where it is cooled be water that fills the compartment or sprays from the bars. Vacuum may be applied to the chambers to help maintain the shape of the plastic product.
• Depending upon the pipe size, cooling system of vacuum sizing machine may use either spray cooling or total immersion. Usually, total immersion is required when diameter of pipe is small while spray cooling is suitable if pipe diameter is large.
• After cooling, the plastic product passes through last chamber. Rollers help guide the plastic through the vacuum sizing machine.