Water smart reader

[big-all]

a say 1"[80sq mm] surface and a 1/2"[40sq mm] plunger is about 2x the area so 2x the pressure

 

[JohnW2]

a say 1" surface and a 1/2" plunger is about 4x the area so 4x the pressure

NO - 4 times the force, but exactly the same pressure (give or take any losses). That was the point I was thinking about.

Kind Regards, John

 

[big-all]

edited it to be 2x as its pie r square [x3.17] how ever you say it
if you have twice the surface area then you have twice the force as long as the water cant get to the reverse side off the diaphragm

 

[JohnW2]

edited it to be 2x as its pie r square how ever you say it ... if you have twice the surface area then you have twice the force as long as the water cant get to the reverse side off the diaphragm

As I've implied, it depends upon how one is trying to do it - 'twice the force', per se, doesn't mean a lot. As I said, it might be simple if I think about it carefully, but I have yet to do that! There is also the matter of 'reversing the process' (to turn the main valve back on) that needs to be considered - and which, again, might not be totally straightforward.

Kind Regards, John

 

[JohnW2]

a say 1"[80sq mm] surface and a 1/2"[40sq mm] plunger ...

By the way, I don't understand your arithmetic at all. If you're talking about a 1" diameter surface, that's a bit over 500 mm², not 80 mm².

Kind Regards, John

 

[big-all]

you have a small return spring so when you close the 2mm hole and vent the water the spring opens the plunger

 

[JohnW2]

you have a small return spring so when you close the 2mm hole and vent the water the spring opens the plunger

Yes, a spring would almost certainly be involved, but you would also have to have some mechanism (another 'hydraulic actuator'?) to open the 'vent'.

If you could sketch/scribble how you think (the totality of) this could work, I might be better able to understand what you have in mind.

Kind Regards, John

 

[big-all]

you would have the same actuator that opens the 2mm port to start the process closes the vent port so when you close the port to stop the process it vents the chamber

 

[JohnW2]

you would have the same actuator that opens the 2mm port to start the process closes the vent port so when you close the port to stop the process it vents the chamber

Fair enough, but I'd still like to see some sort of illustration of the totality of what you have in mind.

Kind Regards, John

 

[big-all]

afraid i cant do drawing or at least transfer them
i used to be a train driver and air braked worked via triple valve or distributor
the triple valve worked very simply reduce the bake pipe say from 70-60psi
the triple valve on each vehicle would operate and go to the same level as the train pipe so air from the aux res would then fill the brake cylinders until it equalized then its in the hold position you can further reduce to give a greater brake application as many times as you like untill the train pipe is at 50psi then when you want the brakes to release you charge the bake pipe back to 70psi
now the point is the triple valve is about the size off a cup off coffee but can stop a train
now phase two because you are just using electric to control you can use the ep brake [electro mechanical ]valves that simply uses the same air so like water not varying the flow but using its power with diagphrams to operate with leverage
https://duckduckgo.com/?t=ffsb&q=epb+brake+tripple+valve&atb=v227-7&iax=images&ia=images&iai=http://images.fineartamerica.com/images-medium-large/westinghouse-quick-action-triple-valve-sheila-terry.jpg