Valve to vent entire volume upon reaching a set pressure

Click For Summary

Discussion Overview

The discussion revolves around finding a method to reproducibly drop the pressure of a container by a known amount while it is being pressurized. The context includes experimental setups involving variable pressurization rates and the search for appropriate valves or mechanisms to achieve controlled pressure drops.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested, Experimental/applied

Main Points Raised

  • One participant seeks solutions for achieving a controlled pressure drop during pressurization, asking about available valves for this purpose.
  • Another participant requests clarification on the specifics of the pressure drop, suggesting that numerical values would help in understanding the scenario better.
  • A participant specifies that they want to decrease the pressure by 2 psi while the container is being pressurized at a rate of 2 psi per second.
  • Concerns are raised about the variability in pressurization rates as the receiving vessel's pressure increases, leading to the suggestion of a computer-controlled vent valve that adjusts based on real-time pressure readings.
  • One participant mentions that for maximum precision, a feedback loop with a computer is advisable, while a simpler solenoid valve may suffice if high precision is not required.
  • A link to a search for proportional pressure regulators is provided, indicating a potential resource for further exploration.

Areas of Agreement / Disagreement

Participants express varying opinions on the best approach to achieve the desired pressure control, with some advocating for high precision methods and others suggesting simpler solutions. No consensus is reached on a specific method or solution.

Contextual Notes

The discussion does not specify the accuracy or repeatability requirements for the pressure drop, which may influence the choice of method. Additionally, the dependency on the changing pressure of the receiving vessel complicates the problem.

nlis12
Messages
32
Reaction score
3
Greetings,

I have an experiment that pressurizes a small volume at variable rates. 1, 2, and 3 psi/sec. I am trying to think of a way to reproducibly drop the pressure of the container by a known amount while it is being pressurized. Are there valves for this type of experiment? What are other ways I can achieve a controlled pressure drop?

Any help or insights are welcome.
Thank you.
 
Engineering news on Phys.org
Can you clarify the expression "drop the pressure of the container by a known amount while it is being pressurized?" Some numbers here to get a handle on the pressures being discussed would be helpful.
 
Let's say the container is being pressurized at 2psi a second. I want to decrease the pressure of the system by 2psi at any point in time in a reproducible way.

Does this make sense?
 
The problem is that the pressurization rate will change as the receiving vessel's pressure rises so there is no one vent valve flow rate and time to shutoff combination that will work. The only possible solution I can envision right now might be a possibly vent valve controlled by a computer module with a receiving vessel mounted pressure sensor that is programmed with a time vs. sensing pressure opening time curve contoured to the system supply rate vs the vent valve flow rates that when triggered will open the vent valve for a time proportional to the supply vs vent valve flow rates at any given vessel pressure.
 
You don't say how accurate and how repeatable it has to be. For maximum precision, I agree with @JBA , a feedback loop and a computer is the most direct approach. But if you don't need precision, then a solenoid valve that opens for a fixed duration of time may be good enough.
 

Similar threads

Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
13
Views
4K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 9 ·
Replies
9
Views
5K