GB1395403A - Diaphragm pump having a safety arrangement - Google Patents

Abstract

1395403 Diaphragm pumps; compressors; vacuum pumps E BECKER 18 July 1972 [15 Sept 1971] 33602/72 Headings F1A and FIN A diaphragm pump for gases or liquids comprises a working diaphragm 5 and a safety diaphragm 6 spaced apart to define a chamber 20 in which leakage collects to operate indicating means when the working diaphragm fails, the safety diaphragm 6 being more resilient than the working diaphragm, being reinforced or maintained at less severe temperatures or subjected to less severe flexing than the working diaphragm, to ensure that the working diaphragm fails before the safety diaphragm. As shown, chamber 20 communicates with an analyzer for detecting leakage and with a compensating chamber 51 with a diaphragm 52, which is connected to atmosphere or a controlled pressure through connection 53 and functions to absorb pressure variations in chamber 20 during normal operation. Contacts 56, 57 are closed on complete deflection of diaphragm 52 due to failure of diaphragm 5 (when acting as a vacuum pump). Chambers 20 and 51 may be filled with the fluid to be pumped to avoid contamination when diaphragm 5 fails. Diaphragm 5 may act to close the inlet port during the discharge stroke, Fig. 5 (not shown). In Fig. 2 (not shown), a pressure gauge is connected to chamber 20. In Fig. 3 (not shown), the safety diaphragm is cooled by a fluid circulating through a cooling coil (22).