The position of the preheating wire at the pump outlet has been changed.
Thread Content
Nowadays, the devices are all canned pumps. The preheating line is as shown in Figure 1. There is only one outlet valve, but the media are all aromatic hydrocarbons. Therefore, it is considered that if the outlet valve leaks internally during future pump maintenance, it will cause poisoning to the operator. Therefore, I want to extend the preheating wire across the front of the outlet valve, as shown in Figure 2. The purpose of this is that the backup pump warms the pump without requiring the outlet valve to be slightly opened excessively, and reduces the flushing of the valve flap by small flows. But now there are two problems: 1: As shown in Figure 1, internal leakage occurs in the outlet valve of the machine pump. Is small flow flushing the main cause? If the solution in Figure 2 is changed, will the actual effect be able to reduce the occurrence of internal leakage in the outlet valve? 2: What is the failure rate of the canned pump and whether it is repaired as frequently as the centrifugal pump? This mainly considers the necessity of changes.
Now I have two questions 1: Does the erosion of the valve disc by small flow erosion play a dominant role in the valve internal leakage problem? 2: What is the failure rate of canned pumps? If it can generally run stably for a year, there will be no need to change it.…
The failure rate of canned pumps is very low now, and running for 2 years is a basic requirement.
1. The erosion of the valve disc by small flow rate is not the main factor causing the internal leakage problem of the valve, so it is not recommended to change it in this way. If the second-stage preheating hotline valve internal leaks, it will affect the later inspection and maintenance, which is also a design consideration. 2. Whether the canned pump maintenance is frequent depends on the quality of the pump and whether the working fluid is clean, which is directly related
In addition, consider setting up a double valve on the preheating wire, and moving the inlet of the preheating wire to the front of the outlet valve. The first channel of the double valve is usually fully open and closer to the inlet end.