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Valve modding problem

Unread postPosted: Sun Sep 23, 2007 7:41 pm
Author: watto
Ive modded a holman sprinkler valve, the same as the one in this tutorial http://www.spudfiles.com/forums/modding-the-wrong-type-of-sprinkler-valve-t3821.html

But when I blow into the right end and the pipe tap is covered, air still leaks slowly past the diaphragm. What do you think I should do. the pipe tap is well and truly sealed, and I've left the solenoid on so It cant be that hole, should I put some lube inside it or something?

Unread postPosted: Sun Sep 23, 2007 7:48 pm
Author: BigJon
make sure that the diaphram inside is clean or else it won't seal right.

Unread postPosted: Sun Sep 23, 2007 7:55 pm
Author: thespeedycicada
here are some problems i can think of.One did you leave that little rod with the spring in the solenoid? if not it will leak.Two are you blowing through the right hole the arrows should be facing the barrel and be pointing away from the chamber or your mouth when testing if not it will leak.And finally did you leave the spring in there mine would not work without it.Hope this helps.

Unread postPosted: Sun Sep 23, 2007 8:29 pm
Author: watto
Yeh the rod and spring are still in and im blowing in the right direction, the diaphragm is new so it's all clean.

Just another thing I noticed, when you are not covering the pipe tap, Is it meant to be hard to blow into? I'm assuming once it's attached to the chamber and has a lot of pressure behind it then then diaphragm will move all the way up, is that right?

Unread postPosted: Sun Sep 23, 2007 8:38 pm
Author: thespeedycicada
no it shouldnt be to hard to blow into ive never used those valves before so without some pics of the internals and externals im out of ideas.

Unread postPosted: Sun Sep 23, 2007 8:50 pm
Author: mopherman
MY sprinkler does not seal when I blow into it. It just needs more pressure behind it.

Unread postPosted: Sun Sep 23, 2007 8:55 pm
Author: windshrike
Dang mopherman, you beat me to it :x .
Watto: If you already know this, just bear with me.
A diaphragm valve uses a piece of rubber(thats the diaphragm) between two areas of pressurized air, and when one area is exhausted, the pressure difference moves he diaphragm, releasing the air in the other area. However, if the pressure is not great enough to push the diaphragm with enough force to seal against the other area of air, then a small amount of air will leak past, hence your problem.

Unread postPosted: Sun Sep 23, 2007 9:37 pm
Author: watto
you guys are so smart, thanks