| 摘要 |
The invention relates to a process for pretreating the coupling elements of a gas-tight sleeve-pipe coupling with a metallic sealing seat and an abutment shoulder for repeated screwing together of casing and tubing, made of high-alloy steel, for the petroleum industry and natural gas industry, in which the sealing and thread region of the sleeve is provided with a metallic coating and lubricant is applied, before screwing together, to the cleaned sealing and thread regions of the coupling elements. To provide a simple pretreatment of the coupling elements of a gas-tight sleeve-pipe coupling, by means of which repeated screwing together is reproducibly ensured for high-alloy, austenitic steels and nickel-based austenitic materials, it is proposed that, for coupling elements of austenitic steels with chromium and nickel contents greater than 20% by weight and molybdenum contents greater than 2.5% by weight, and of austenitic materials with nickel contents greater than 50% by weight and chromium and molybdenum contents greater than 10% by weight, a ceramic-based, metal-free paste known per se be applied, before screwing together, as lubricant to the sleeve and to the bright spigots of the pipes which are to be coupled. …<IMAGE>… |
