Determination of the opening pressure and flow rate of the safety valve
Thread Content
1. How is the opening pressure of a safety valve determined? When the valve core moves slightly away from the valve seat, only a very small amount of gas is released – is this pressure considered the opening pressure? If not, then what exactly constitutes the valve’s opening pressure? 2. Determination of the safety valve’s flow rate: At what pressure should the flow rate of a safety valve be measured? When the valve is just slightly opened, the flow rate is very low; as the inlet pressure increases, the flow rate gradually rises. So at what pressure should the flow rate be measured in order to obtain an accurate value of the safety valve’s actual discharge capacity? The article at http://www.docin.com/p-1711446194.html states that during flow measurement, the pressure should not exceed 3% of the set pressure, or the higher of these two values, which is 15 kPa. If the pressure at the moment when the valve is just slightly opened and bubbles start to appear is taken as the set pressure, then the measured flow rate will be extremely low.
I did learn about it a few days ago, but I’ve forgotten. As I get older, I can’t remember things as well. It seems that when the pressure reaches 97% of the set value, the first bubble appears; once the set pressure is reached fully, the flow rate increases significantly.
The set pressure required for a safety valve is, under normal circumstances, lower than the pressure value set for the container. On the setup diagram of the container, we can see the accurately indicated working pressure values (maximum and minimum pressure values). Therefore, we can determine the setting pressure of the safety valve based on the maximum pressure value indicated above. The set pressure of the safety valve is 1.05 to 1.10 times the operating pressure. To determine this, we can use the pressure-setting nut in the safety valve to adjust its set pressure; by rotating the safety valve, it is possible to decrease or increase the set pressure. Thus, it can be determined.
This post was last edited by WuduBuZhangfu on July 6, 2018, at 16:59. 1. As long as any medium is discharged, the valve is considered to be open. The opening pressure of a valve, also known as the set pressure, is the predetermined pressure at the moment just before the valve opens. There are multiple parameters for setting a safety valve, and the opening pressure is one of them. 2. Flow rate measurement of the safety valve: The flow rate at the discharge pressure set for the safety valve. The flow rate is independent of the set pressure. There are various types of safety valve structures, and regardless of the structure, their purpose is to enable overpressure relief. When considering flow requirements, a safety valve with an appropriate structure should be selected. Excessive emissions also represent a loss for the piping system, and can even lead to an imbalance in its operation.