Balance pipes before and after the valve
Thread Content
In the workshop, I saw a very thin pipe connecting the valve on the main pipeline from both the front and back. The people on site said it was a balance pipe, but I’m not sure exactly how it functions. I would like to ask everyone what purpose this thin pipe serves, when it is used, and how to use it
It may be that the pressure of the medium in the pipeline is very high, or the temperature is very high, making it difficult to open the valve, or there is preheating before and after the valve.
The pressure is 70 kilograms; with this branch valve open, is it easier to open the main pipeline valve?
That's how it is. The force F = (P_front – P_back) * S. Since the cross-sectional area of the capillary is very small, it can still be opened manually even with a large pressure difference; after it is opened, the pressure difference between the front and back decreases. Even though the cross-sectional area of the valve is larger, the low pressure difference allows it to be opened and closed manually as well.
When the pressure difference before and after the valve is high and the pipe diameter is large, it is difficult to open the valve; therefore, a smaller valve is opened first to balance the pressures on both sides of the larger valve.
First, open the small valve to equalize the pressure before and after the large valve, making it easier to open the large valve
The balanced pressure sometimes prevents it from opening
Is it a high-pressure steam line? The smaller line is used for preheating and warming the pipes
When the main valve is first opened, the bypass valve is used to equalize the pressure; at this stage the pressure difference across the main valve is large, making it difficult for the valve to open