| 摘要 |
At drilling in earth layers and simultaneous forcing in of casing tubes it is desirable to use casing tubes of plastic material, such as PEH plastic. This is made possible through a special forming of a casing shoe which gives a firm connection between the casing shoe and the casing tube. The casing shoe comprises an outer annular part (3) and an inner annular part (8) with against each other corresponding conical sections (6, 11) between which the casing tube can be clamped.
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