[Greenbuilding] Special Valve

[Speireag Alden]

Sgrìobh Rob Tom:

>If I understand you correctly, it looks like you want something like 
>a backflow prevention damper, or in plainspeak, a flap that swings 
>in one direction only, and which opens only when a certain pressure 
>is reached or exceeded.

     Spot on.

>If that's correct, would it not be a simple matter of using either a 
>spring or counterweights to restrain the flap from opening ?

     Well, except that I need to do it in a pipe which runs uphill 
from the valve.  I'd love to try what you suggest, but I'm not sure 
how to put weights on a swinging valve which is inside of the line. 
I have the feeling that I'm missing something obvious here, though.

>In lieu of some number-crunching, it would be a matter of trying 
>different sized springs until it allows the flap to open at the 
>desired pressure, or adjusting the counterweights.

     That's more fun anyway.

>For the flap apparatus itself, if you didn't want to fabricate it 
>yourself out of brass or stainless or perhaps salvaged from the 
>throttle assembly of an automobile, perhaps the plastic ones that 
>are used to prevent backflows in house drainage tile would do the 
>job ? Or perhaps toilet tank parts ?

     Is there some device which can hold pressure with a lever 
attachment on the outside, but a swinging gate on the inside?

-Speireag.

-- 
Leaves starting to turn
Anticipation shivers
Me as winter comes

-Speireag.