1. Electric diaphragm pump start-stop load operation: the diaphragm pump is driven by a frequency conversion motor. If the start-stop load is too large or too small, in order to avoid the above situation as much as possible, the rigid adjustment of the start-stop load is controlled at about 30%, and the installation of the instrument for increasing or decreasing the load must be completed within a period of time. The effective maintenance of the frequency converter is technically realized.

2. Diaphragm pump instrument air and lubricating oil pressure system operation: diaphragm pump instrument air and lubricating oil pressure interlock with the main motor. The fuel injection and drain valves of the propellant fluid are gas-closed valves. They should always maintain a certain air pressure. The minimum working pressure of the two valves is not less than 0.4 MPa, so even after stopping the pump, the instrument air pressure is generally maintained above 015 MPa. To avoid insufficient or too much liquid in the push chamber, the air supplied to the valve is filtered and the oil is atomized. When the diaphragm pump is running, the lubricating oil pressure should not be lower than the pressure interlock value (0115MPa), the pressure difference of the lubricating oil outlet filter should not be too large, the steel ball in the lubricating oil flow peeper should be in the upper limit position, and the adjustment range E should not be too large when adjusting the flow, so as not to cause the chain jump because the instantaneous flow is too fast. Through the above process improvement, proficient in the operation points, diaphragm pump always has a stable process environment during operation. In the past year, it has only jumped once for electrical reasons, resulting in long-term, safe and efficient operation.

3. The flow characteristics of diaphragm pumps refer to the relationship between the relative flow of the medium through the valve and the displacement (the relative opening of the valve). There are four main ideal flow characteristics: straight line, equal percentage (logarithmic), parabolic and fast open. The characteristic curve and shape of the valve core, commonly used ideal flow characteristics are straight line, equal percentage (logarithm) and fast opening.

4. The selection of flow characteristics of diaphragm pump can be calculated theoretically, but the methods and equations used are very complicated. Adopt empirical guidelines to consider the following aspects: 1) analysis and selection of regulatory quality in the regulatory system; 2) consideration of process piping; 3) Load change analysis.

5. Select the flow characteristics of the diaphragm pump, and determine the shape and structure of the valve core according to its flow characteristics. However, for diaphragm valves and butterfly valves, due to their structural characteristics it is impossible to achieve the required flow characteristics by changing the surface shape of the spool. At this point, this can be achieved by changing the feedback cam shape of the valve positioner.