I have two questions about pumps for everyone.
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One is at the pump’s outlet; there is a pipe that consists of three sections connected by two flanges. It seems to extend from near the pump outlet and then return to the pump head. I’m not sure what its purpose is – is it meant to prevent the pump outlet from getting blocked? But it seems that the liquid inside this pipe still makes its way back to the pump head. If the pump outlet is blocked, what’s the point of this circulation of liquid? Additionally, there is a long cylindrical container above the pump, with two pipes connecting it to the shaft area near the pump head. It seems that there are also power and signal wires connected to this container. I’m not sure what this is for – is it used to control the lubricating oil, or to regulate the pressure at the pump outlet? Please let those who know answer, thank you!
You are referring to mechanical seal flushing; the first case should be Plan11, and the second case should be Plan32.
After looking at it for so long, it would be better if the original poster just posted a picture directly. As you said, I would roughly say: one is a balance tube, used to balance the axial force of the rotor ； For the seal fluid cooler of another shaft seal, in the case of volatile media, this tank is generally equipped with an exhaust pipeline as well. If there are also instrumentation leads connected, they are primarily used to monitor the level, temperature, and pressure of the sealing fluid, in order to ensure an effective seal. There are also many related images and explanations on the forum, right in this section.
Send a picture; everyone can help analyze it for you.
Let’s answer your first question first: that tube is a balance tube, which directs the liquid from the high-pressure side to the low-pressure side, thereby reducing the pressure on the high-pressure side and bringing its pressure in balance with that of the low-pressure side. Those signal line terminals are connected to the PLC. It is used to monitor things such as the temperature of the bearing shells, vibration, shaft displacement, and the temperature of the lubricating oil, among others
What was said upstairs is almost completely correct; it’s that thin tube inserted into the shaft. I guess it’s used for flushing the mechanical seal, right?
The first one should be a self-flushing tube with a single-face mechanical seal (PLAN11 scheme). The second one is an auxiliary system equipped with a series-connected mechanical seal or a double-face mechanical seal; the long cylindrical container represents the seal fluid tank, while the power cables and signal wires are those used for devices such as pressure switches and level switches.
The camera function on mobile phones is good enough these days; why not take a photo? I still don’t quite understand after all this talking
The first one should be the pump’s balance line; the second one should be the flushing line for the mechanical seal. The instrumentation line is used to monitor leaks in the mechanical seal – once there is a leak, both the pressure and liquid level in the seal tank will change
I think it should be the pump’s backwash line; we have plenty of those here!
1. If it is a single-stage pump, it should be the self-flushing water pipeline for the mechanical seal. 2. If it is a multi-stage pump, it should be the pump’s balance pipe. The signal line is related to the pump’s online fault diagnosis system, which is used to monitor things such as the temperature of the pump’s bearing shells and its vibration levels
The original poster didn’t explain things clearly enough. Your first question is about connecting something from the pump outlet to the pump body; in that case, it shouldn’t be a balance line, as balance lines are generally connected from the pump body (near the outlet side) to the pump inlet. It’s better to upload some pictures so it’s clearer
The previous question was aimed at reducing issues such as insufficient flow pressure and vibration that occur in pumps when cavitation takes place, while the latter question seems to relate to the self-cooling and lubrication of the pump bearings
Is the first question about backflow?