can have additional piping and valving members in its configuration such as valves branching pipes by pass pipes and drain pipes and members for process control or maintenance such as a pressure gauge a pressure transducer a pressure controller a vacuum controller a residual amount measuring instrument a leak sensor an ejector a mass flow controller mfc or a mass flow meter mfm a filter and a flow controller for a gas purifier the fluid feed apparatus may further have a heater and a heat controller for heating the system partly or wholly to increase the inside cleanness the heater can be installed to heat for example the s w line the connecting pipe c w or the valves 6 7 8 9 10 11 15 16 20 and 22 the heating temperature is set freely according to the material of the apparatus and the fluid to be heated but usually ranges from 30 u00b0 to 300 u00b0 c preferably 50 u00b0 to 150 u00b0 c each of the containers may have an auxiliary port serving for the maintenance of the container such as a fill port or an exhaust port and may be equipped with a pressure gauge a level meter a residual amount measuring instrument etc in order to protect a vacuum pump vacuum source at the downstream end of the evacuation pipe it is advisable to put in an absorbent or adsorbent for trapping the source material or the cleaning and or diluting liquid e g a solvent upstream the vacuum pump useful absorbents or adsorbents include activated clay active alumina natural or synthetic zeolite molecular sieves and activated carbon the members making up the apparatus such as the containers valves joints and pipes should be.