Nick, everytime you post something like this I get these premonitions of seeing you on the news someday.
Oddly, I hear that kind of stuff all the time. To quote one of my good friends: "Nick, you are either going to end up in jail on death row, or you are going to be very, very rich." Ill take it as a compliment. :-)
What you have shown us will not work as a pressure regulator. It will put out no pressure until you apply pressure high enough to contract the spring, at which point input and output will see the same pressure in a static situation.
I have real trouble wrapping my head around this. I look at design three, and to me it looks like it would work, but I know it won't. Maybe because liquids are not elastic? Would design three work on air?
A flow restrictor will effectively reduce pressure when your water-using application is active, but it won't necessarily be steady pressure.
Exactly what I've been battling with! My initial attempt was to use a simple valve that wasn't open much, but as soon as the water stopped flowing, the pressure equalized and everything broke lose.
I would recommend against designing and building a pressure regulator on your own. If the pressure is low, you probably don't need one; if the pressure is high, it would be a silly health-risk to take. There are many companies that do a great job at building one and sell them pretty cheap - check out AirTrol.
Good point. Noted.
If you still want to make one yourself, check out the design principles on the internet - blueprints from manufacturer or wikipedia. Many of these regulators are designed to keep constant pressure by controlled leak, so make sure whatever you regulate is not dangerous; otherwise, look for the non-leaky type.
I've had difficulty finding this concept clearly diagrammed and explained. Do you happen to have a link to somewhere that has a good write up about how these devices work?
Many of these regulators are designed to keep constant pressure by controlled leak, so make sure whatever you regulate is not dangerous; otherwise, look for the non-leaky type.
I'm regulating water from city pressure, which seems to be quite high here, down to between 10 and 20 psi. I will have access to a drain, so as long as the leak isn't a lot, this would be fine.
What you would need is a secondary pressure vessel, filled by a flow restrictor valve like you've designed; one that would open when the secondary pressure dropped to 10 psi, and would close when the pressure built to 20 psi.
So, this is another thought - if I had the location of the valve higher then the rest of the unit in operation, I could probably use a float carb bowl kind of idea. It's too messy really, and I don't think the flow would be good however.
I've seen in-line regulators for RV's advertised before. This will not work for me, as the pressure is set at 40psi normally, but how do these work? They seem to take up very little room.