Urgent! Urgent! Urgent! Is there a breathing valve with an exhaust pressure of 20-30 kPa? l
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Dichloroethane is stored at room temperature; its vapor pressure is 87 mm Hg at 25 °C. It should be sealed with nitrogen, and if a vent valve and a pressure relief port are used, the nitrogen sealing pressure must be higher than the saturated vapor pressure at that temperature. The discharge pressure of the vent valve should be above 10 kPa. Are there vent valves and pressure relief ports available with a pressure of 20 kPa in this case? What should be done in this situation? Is there a better way? Thank you!
Putting everything else aside, can a tank with a pressure of 20 Kpa withstand such conditions? There is no vent valve, and the maximum pressure reached is 1930 Pa. If the tank is suitable for use, a multi-stage control valve or a self-acting micro-pressure control valve can be employed
It is recommended to draw a process diagram and indicate the process conditions, which will make things clear at a glance. It is mainly the principle part of the breathing valve section. For reference.
The vapor pressure of dichloroethane, the medium mentioned by the poster, which is around 20–30 kPa, refers to absolute pressure. Nitrogen is injected to maintain a constant pressure in the storage tank; therefore, there is no issue of a gauge pressure of 20–30 kPa (g).
So the pressure of the nitrogen seal can still be quite low, right? The pressure of the nitrogen seal is gauge pressure, isn’t it?
For conventional atmospheric-pressure storage tanks, it is sufficient to consider the nitrogen sealing pressure and the venting pressure of the breather valve. For example, when the pressure at the top of the tank drops to 0.2 kPaG, the nitrogen seal valve is opened to supply nitrogen into the tank; nitrogen supply is stopped when the pressure reaches 0.5 kPaG ； When the pressure at the top of the tank rises to 1.5 kPaG, the breather valve vents air outward.
The maximum discharge pressure of the breather valve can reach 100 KPA.
If converted to gauge pressure, wouldn’t that be negative pressure? That can’t be right.
Then, converted to gauge pressure, it becomes negative pressure.