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Pressure ratings for sprinkler valves

Posted: Wed Apr 09, 2008 1:55 am
by biggsauce
Hey yall I got to thinking about why a sprinkler valve would be rated to say 150 psi. Is the the plastic the valve is made of that can handle the pressure or is it another component? Maybe it invlolves the solenoid or the diaphram cap. At first I thought that the diaphram would rupture or tear a higher pressures, but pressure is equal on both sides of the diaphram when static, and the rushing air shouldnt cause it to 'flap' to the point of tearing.

Then again, maybe this is a lot simpler than I'm making it and the vavle body itself is in danger of rupturing at exceedingly high pressures.

What do yall think? Has anyone seen a sprinkler valve pressurized to destruction? Or heard so?

Re: Pressure ratings for sprinkler valves

Posted: Wed Apr 09, 2008 2:29 am
by starman
biggsauce wrote:Hey yall I got to thinking about why a sprinkler valve would be rated to say 150 psi. Is the the plastic the valve is made of that can handle the pressure or is it another component? Maybe it invlolves the solenoid or the diaphram cap. At first I thought that the diaphram would rupture or tear a higher pressures, but pressure is equal on both sides of the diaphram when static, and the rushing air shouldnt cause it to 'flap' to the point of tearing.

Then again, maybe this is a lot simpler than I'm making it and the vavle body itself is in danger of rupturing at exceedingly high pressures.

What do yall think? Has anyone seen a sprinkler valve pressurized to destruction? Or heard so?
Same reason other parts, pipe, connectors are rated a certain rating.... mechanical design, thermal characteristics, material capabilities all play into the calculation. The ratings are also conservative so you'll go to 200-300 psi before actual failure.

As for specific sprinkler failure, I imagine the diaphram would go first, not from steady state, but stress of and during activation. After that, the threaded input and output housings.

The typical part failure on sprinklers is the solenoid, but not from pressure issues...they just wear out.

Posted: Wed Apr 09, 2008 3:08 am
by Killjoy
As I recall at high pressures it is generally the diaphragm which gives out and tears. And the valve body though looks pretty sturdy, it probably could take 200 psi or more pretty easily before having to worry about failure.

Check out this how-to by noname, he mods the diaphragm for some serious flow and abuse.
http://www.spudfiles.com/forums/how-to- ... t7038.html

Posted: Wed Apr 09, 2008 8:41 am
by biggsauce
Alright yeah that makes sense about the diaphram ripping. I'd like to hear one actuate at 200 psi and above, I bet its a pretty scary sound.
But I'll leave that up to those braver than myself

Posted: Thu Apr 10, 2008 2:11 am
by Killjoy
But I'll leave that up to those braver than myself
Or those much less intelligent then yourself haha....Hmm I might have to try this.