Cooling in cooling bed has a chain of cooling bed, worm cooling conveyor and rack-type cooling bed. According to the performance requirements of large diameter welded pipe, can use different ways to cool.

Forced cooling. Large diameter welded pipe for metal has certain organization and physical properties, should take the control of cooling speed. Such as bearing tube, in order to prevent the precipitation of carbide network, cooling rate no less than 50-70 - c/min, and take the way of ventilation or water mist forced cooling.

Natural cooling. There is no special performance requirements of large diameter welded pipe, can be in natural cooling in the atmosphere.

, reducing the large diameter welded pipe after the temperature is in commonly 700 ~ 700 ℃, below must be cooled to 50 ℃, and then sent to the relevant finishing equipment processing, in order to improve working conditions, improve the quality of finishing.