| 摘要 |
The invention relates to a device for coating steel pipes with tubular films of thermoplastic, in particular polyethylene, the steel pipes being first guided through a subatmospheric chamber and then through an extruder head connected thereto and serving to produce the tubular films and, by means of the subatmospheric chamber, a subatmospheric pressure of between 450 and 550 mm water head being maintained in the interspace between the pipe surface and the tubular film emerging from the extruder head. To prevent undesired deformation of the tube or tearing thereof, this resulting from sudden changes in the subatmospheric pressure between the pipe surface and the extruded tube, it is proposed that the pipe inlet opening (11) of the subatmospheric chamber (2) have a diameter which is 0.5-1.5% greater than the nominal diameter of the pipes to be coated. Individual developments are given in the subclaims. <IMAGE>
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