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PuK - Process Technology & Components 2023

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Pumps and Systems

Pumps and Systems Diaphragm metering pumps Table 2: Operating fluid Fluid Aqueous Operating temperature [°C] 20 Density [g/cm 3 ] 1.00 cases are standardized. This means In the metering application, the deterioration of the valve condition due to that the set point is represented by the value 1 and the deviations refer to this value. In the following, we could already be measured at time t 1 an increased structure-borne noise . will therefore speak of “standardized The operator receives a warning from characteristic values.” the Smart Monitoring System that the limit value has been exceeded. At 6. Predictively measure valve wear this point, the valve wear has no influence on the performance of the In processes with abrasive fluids and plant, which is visible in the flow rate high pressures, the valves of diaphragm metering pumps are subject At time t 2 (cf. Fig. 5). , the flow rate measurement also shows that the limit value to particularly high stress. Valve wear affects the sealing ability of the pump has been exceeded. The valve wear head during the stroke and thus the is now so advanced that it has a volumetric performance of the pump. nega tive effect on the performance For this reason, it is important for operators to monitor valve wear in or- Without valve monitoring, wear of the plant. der to schedule maintenance to avoid only becomes measurable when the unplanned shutdowns. It must also flow rate in the piping decreases (t 2 ). be ensured that the process quality is At this point, the process has already not impaired by valve wear. been disrupted and controlled main- Fig. 4: Comparison of worn valve set (l) and as-new valve set (r) tenance planning is no longer possible. With valve monitoring, signs of wear can be detected before they have a negative impact on the process (t 1 ). Viscosity [mPa·s] 1.04 Plant diagram (P&ID) Fig. 3: Design of the pilot plant Fig. 5: Curve of structure-borne noise measurement (top) and flow rate (below) Identify worn valves With multi-head pumps in particular, it is difficult to detect wear. Both the damage pattern and the affected valve must be identified. The previous example showed how valve wear is detected before it has a nega tive effect on the performance of the plant. With the Smart Monitoring System, each valve in all pump heads can be analyzed individually, so that the cause of the fault can be determined precisely. Analyzing the individual pump heads shows that the structure-borne noise has increased in the second pump head (B) (Cf. Fig. 6). In this case, the Smart Monitoring System issues a plain text message about the valve wear that is occurring and also indicates which valve in which pump head is affected. 24 PROCESS TECHNOLOGY & COMPONENTS 2023

Pumps and Systems Diaphragm metering pumps Conclusion Valve monitoring not only enables valve wear to be measured before it affects plant operation. It also makes the exact localization of the affected valves possible. This creates the basis for targeted, condition-oriented and predictive maintenance. 7. Prevent diaphragm ruptures Fig. 6: Structure-borne noise measurement across all pump heads Diaphragm ruptures are always critical for diaphragm metering pumps and lead to immediate process interruption. Since diaphragm ruptures can have various causes, prevention is difficult. While diaphragm ruptures due to foreign bodies in the fluid or wear cannot be predicted, hydraulically induced diaphragm ruptures are easy to identify in certain operating situations. The Smart Monitoring System determines the length of the “snifting phase” (leak supplement phase) for various diagnoses. In the sniffing phase, the hydraulic oil lost during the pressure phase due to internal leakage in the pump head is replenished. When the length of the sniffing phase (t 1 ) decreases, a condition develops that leads to diaphragm rupture (t 2 ) (Cf. Fig. 7). The system issues a warning when the sniffing phase can no longer be measured. In many cases, operators can see in good time when a hydraulically induced diaphragm rupture is imminent and can react accordingly. Fig. 7: Measurement of the sniffing phase at the pump head Conclusion Monitoring pump hydraulics enables undesirable conditions to be detected in good time and prevents hydraulically induced diaphragm ruptures. Monitoring makes controlled shutdown and maintenance possible. 8. Avoid pulsations in the piping Piping and pulsation dampers are often subject to the inherent vibrations of the system, which can develop into pulsation shocks. These shocks not only endanger the process, but are also a safety risk. Monitoring the pump also simultaneously enables the vibration behavior of the peripher al systems to be monitored. Figure 8 shows a peak of the pressure-side pulsation in the piping, the “coupling pressure pulsation” (t 1 ). At the same time, the discharge pressure of the pump is constant during WATER AS A TOOL. High-pressure pumps Ultra-high-pressure units Accessories / water tools 250 – 3.000 BAR www.woma-group.com PROCESS TECHNOLOGY & COMPONENTS 2023 25

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