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The last 10 posts

Wednesday, April 17th 2013, 1:51pm

by JohnsonBrewer

Took the easy way out ( this time ) and ordered PGV's. I intend to leave the old SRV valve bodies glued in and swap out the old SRV tops with PGV tops with flow control. Also ordered 100 mesh ss filter to install at the front of the run. If I have any problems ( beyond replacing a diaphragm here and there ) in a couple of years I'll cut them out and go with a different brand, either DV's or 2400's. Thanks for everyone's opinions. I'll check back in later and let you know how the spring start-up went.

Monday, April 15th 2013, 11:21pm

by Central Irrigation

I am still waiting to hear if the SRV and PGV bonnets are interchangeable.

Edit: Scratch that...the SRV is offered in a flow control version. Exact same diaphragm and selonoid as the PGV and a guaranteed fit.

Monday, April 15th 2013, 10:58pm

by JohnsonBrewer

I'm sold on the 100 mesh filter, still mulling which valve to go with. Easiest to do is put the PGV w/ flow control heads on the original SRV valve body, but I'm giving the Irritrol 2400's a close look. Thanks again to everyone for their input.

Monday, April 15th 2013, 9:05pm

by pass1

I would concur with Central in that the flow controls main function limits the opening movement of the diaphragm. This smaller opening creates a smaller flow as well as a small decrease in pressure downstream. The force on the upper part of the diaphragm is a function of the area only and has no bearing on the opening size of the of the diaphragm. ( pressure= force(lb) / area(in sq). That being said, some valves need more of a pressure loss through them to operate properly then others. and at 3gpm there is minimal pressure loss through most 1" valves. You will have to check the flow chart for this particular valve to see its operational requirements. So, a flow control may help in this situation in that it can create a greater pressure loss through it by turning the flow down. I would still take Centrals advice on the filtration and also the advice to add a main spin down 100 mesh filter.

Monday, April 15th 2013, 6:09pm

by Central Irrigation

No, it does not add pressure to the spring. In fact it actually does the opposite. The flow control actually makes contact directly to the diaphragm, not through the spring. A flow control only limits how far a diaphragm can open, thus controlling how much water can can flow through the valve. There is a case that could be made that if using a flow control, the diaphragm would have less distance to travel in order to close. However, the diaphragm will only open as much as the flow dictates. So i guess i fail to see how a flow control would help.
Flow controls allow a system to be "optimized' in almost the same way your grandfather tuned the carburetor on his truck. With the valve open, you throttle down the flow control until you notice it is beginning to restrict the flow. Then you back out the control a half-turn. What this does is minimize the movement of the valve diaphragm. The less a valve diaphragm flexes, the longer it will last, and the more reliably it will perform.

This especially matters on systems with low flows. On a low-flow system, you might even leave the flow controls in a position where they are slightly restricting flow, because (for reasons involving hydraulics) valves so adjusted have more force helping them to close.
Ha Ha! My 1975 Camaro had a carburetor too!
I can honestly say that I've not run into an instance where flow control was needed due to low flow conditions. And this includes drip zones.
Perhaps Boots is correct, and that is all that is needed. Maybe swapping out the SRV cap for a PGV flow control would help. Don't know if they are interchangeable, as I've never tried. Maybe trying it on a few problem valves would help. Doesn't hurt to try!

Monday, April 15th 2013, 5:16pm

by JohnsonBrewer

Looks like the Toro EZ Flo and the Irritrol 2400 take the exact same diaphragm, correct? Also, the Irritrol is listed with flow control as an option --- 2400 TF, with FNPT. My old valves are 1" so any new ones will be 1" as well. I may go with flow control only because my overall system was designed around my pitiful 3 gpm well output which is at the low end of all of the specs. It's been a challenge for it to keep up in the heat of Kansas summers but it will as long as all of the parts are working, and with a little creative scheduling.

Monday, April 15th 2013, 4:58pm

by Wet_Boots

No, it does not add pressure to the spring. In fact it actually does the opposite. The flow control actually makes contact directly to the diaphragm, not through the spring. A flow control only limits how far a diaphragm can open, thus controlling how much water can can flow through the valve. There is a case that could be made that if using a flow control, the diaphragm would have less distance to travel in order to close. However, the diaphragm will only open as much as the flow dictates. So i guess i fail to see how a flow control would help.
Flow controls allow a system to be "optimized' in almost the same way your grandfather tuned the carburetor on his truck. With the valve open, you throttle down the flow control until you notice it is beginning to restrict the flow. Then you back out the control a half-turn. What this does is minimize the movement of the valve diaphragm. The less a valve diaphragm flexes, the longer it will last, and the more reliably it will perform.

This especially matters on systems with low flows. On a low-flow system, you might even leave the flow controls in a position where they are slightly restricting flow, because (for reasons involving hydraulics) valves so adjusted have more force helping them to close.

Monday, April 15th 2013, 3:56pm

by Central Irrigation

I've installed many an Irritrol 2400 on dirty water well and lake systems and have few issues. The Rainbird DV series is also a good choice and has a flow control option. I would shy away from the PGA, as it also has a filtered diaphragm.

I would advise using 1" valves, as they are the standard size. 3/4" valves would work well also.


Edit: The Toro EZFlo is the exact same valve as the Irritrol 2400, but does offer a flow control option, at a premium price. Another option if you decide flow control is needed.

Monday, April 15th 2013, 3:41pm

by JohnsonBrewer

Thank you Central Irrigation for your comments. If I decide to replace the valves, do you have a couple of recommendations for me to look at? I've seen some good comments on the Irritrols and either the RainBird DV or PGA, but what would you suggest at $20 to $30 per valve for my max flow rate system at 3 gpm? Thanks.

Monday, April 15th 2013, 3:06pm

by Central Irrigation

Not all diaphragms are created equal. Most of my knowledge is in Toro and Irritrol, but have serviced most all. Each valve manufacturer has their own belief on what makes a great valve, thus the differences in valve design. Diaphragm materials seem pretty much standard these days, and life expectency of all seem relatively similar, given optimal clean water conditions. Most of the differences come from the design themselves and how well the valves handle non optimal conditions. Personally, I would not chose a valve that contains a filter or very small bypass passages if dirty water conditions are present. The theory is valid, but the reality of a filter or small passages is that they will get blocked. I believe your SRV and PGV fit this reality. I agree that filtration is a necessity, but also believe that some valves handle contaminents better than others.


If you feel the slime that is accumulating on ypur diaphragm is the culptit, then I agree, replacing the valve may be the way to go. Simply because, yes, the SRV and PGV valve diaphragms do have small orrifices on the diaphragm, that if blocked, would affect its performance. Now, if whats blocking these passages is large enough to be filtered by a seperate filter, then that would be more cost effective. However, I have seen what you refer to as slime, and have yet to find a product that could eliminate it. Possibly a water purification system, but who wants that expense?