Problems with double-diaphragm metering pumps
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1. How many diaphragms does a diaphragm metering pump have? 2. Is there atmospheric pressure between the two diaphragms? If so, how is the hydraulic oil pressure transmitted to the cylinder? I don’t know much about the structure of metering pumps
A dual diaphragm can be considered as a double-layer diaphragm, with a pressure sensor or gauge connected in between; it remains pressed together during normal operation
In a double-diaphragm system, the space in the middle is evacuated; if there is gas present, due to the compressibility of gas, the material-side mechanism will not function. There is a piston-like element on the hydraulic side that pushes the oil to increase or decrease pressure, and the oil then acts on the diaphragm.
In a diaphragm metering pump, the two diaphragms are in contact with each other. During operation, the piston pushes the hydraulic fluid, which in turn pushes the diaphragms; these diaphragms then push the medium, thereby enabling its transfer. Two diaphragms are designed to enable timely detection of whether a diaphragm has ruptured; as long as one of the two diaphragms is damaged, the pressure sensing device located between them can detect it.