Workpiece cleaning plant

A plant, for cleaning workpieces with organic solvent, has piping (60,32,62,66,76,70,70a,74,80) connected such that reduced pressure, produced by a vacuum pump (30) and applied across a solvent vapour condenser (28), can effect two or more of the following operations: (a) drying of cleaned workpieces by creation of reduced pressure in the cleaning chamber (10) and extn. of solvent vapour; (b) distn. of solvent in a storage vessel (12) at reduced b.pt. by reduced pressure creation in the storage vessel, the latter having a solvent heating device (22) and being connected to the condenser (28); (c) solvent filling of the cleaning chamber (10) and/or the storage vessel (12) from a transport container (36) by suction transfer through a filling line (70,70a); (d) solvent transfer from the cleaning chamber (10) and/or storage vessel (12) to the transport container (36) via a drain line (70,70a) by means of reduced pressure applied by a vacuum line (74) connecting the transport container (36) to the vacuum pump (30); (e) solvent transfer from the storage vessel (12) to the cleaning chamber (10) and vice-versa via a connection line (80,80a) by creating reduced pressure in the vessel or chamber; (f) degassing of the solvent for ultrasonically assisted cleaning in the cleaning chamber (10); (g) securing the cleaning chamber lid (10b) on the charging opening by creating reduced pressure within the cleaning chamber (10); (h) reduced operating pressure creation in at least part of the plant components as an explosion protection measure and/or for preventing solvent leakage; (i) back-suction of gases transported by the vacuum pump (30), from a suction line (32) location downstream of the vacuum pump into a reduced pressure plant component (e.g. 12); and (j) pumping a solvent vapour-laden gas vol. from one plant component to another (e.g. 10,12).