"In more than 65 years of LDPE production in industrial scale, especially the first decades were characterized by machinery that was developed more or less on the job. Especially double acting hydraulic intensifiers for HP dosing applications were really something new. So it took very often some years to obtain a stable and reliable performance of the process. Therefore, changes in a good running plant are always kind of risky and not desired. But however, over the time (sub-) suppliers come and go as well as product lines. So pumps or parts of it getting obsolete due to lack of spares. Substitution by single produced parts is no solution on a long term since it increases the operation costs. Replacement by complete new pumps sometimes seems to be risky in terms of process compatibility, on the other hand such big investments could probably question the whole future of old plants. This presentation shows on the example of an obsolete hydraulic pump how those situations can be managed with comparable low costs. Recently realized by Uhde HPT in cooperation with a local partner and the end user. "