| 摘要 |
1. An oilfield pipe (2) made from non-rust-resistant steel or an appropriate steel alloy, with an inner coating (9) of corrosion-resistant material and with connectors (3) made from corrosion-resistant metallic material disposed on both ends, which for instance are provided with weld phases or threads (5) and also with sealing and/or shoulder surfaces (6), the inner coating (9) running out on the connectors (3), characterised in that the inner coating (9) consists of PTFE which has been applied at a temperature of approximately 300 degrees C by means of an extruder head passed through the pipe (2), that the start (10) and end (10) of the coating (9) have a smoothed transition and that the coating (9) extends over at least two thirds up to a maximum of nine tenths of the length of the connector (3). |
