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  #21  
Old 07-29-2014, 02:34 PM
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Wet_Boots Wet_Boots is online now
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Quote:
Originally Posted by SoCalLandscapeMgmt View Post
The ITT style solenoids sucked. The tolerance between the plunger and the stem was so tight that the smallest amount of grit would make them stick. Once the valves got older and you had some mineral build up in that stem it was over. I rebuilt hundreds of old brass valves and converted them to the P/N 206920-01 style solenoid assemblies.
I'm pretty sure those ITT solenoids came directly from hydraulic or pneumatic control applications, which probably would have pre-dated lawn sprinkler diaphragm valves. So, with water instead of air or hydraulic oil, they performed differently.

Speaking of water, I know there is a component I liked in old Rainbird diaphragm valves that would make today's irrigators say "Huh?" ~ I speak of the "Fluid Resistor"
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  #22  
Old 07-29-2014, 02:36 PM
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Ron Wolfarth Ron Wolfarth is offline
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Quote:
Originally Posted by Wet_Boots View Post
I'm pretty sure those ITT solenoids came directly from hydraulic or pneumatic control applications, which probably would have pre-dated lawn sprinkler diaphragm valves. So, with water instead of air or hydraulic oil, they performed differently.

Speaking of water, I know there is a component I liked in old Rainbird diaphragm valves that would make today's irrigators say "Huh?" ~ I speak of the "Fluid Resistor"
A water hammer reduction strategy.
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  #23  
Old 07-29-2014, 03:02 PM
SoCalLandscapeMgmt SoCalLandscapeMgmt is online now
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Quote:
Originally Posted by Wet_Boots View Post
I'm pretty sure those ITT solenoids came directly from hydraulic or pneumatic control applications, which probably would have pre-dated lawn sprinkler diaphragm valves. So, with water instead of air or hydraulic oil, they performed differently.

Speaking of water, I know there is a component I liked in old Rainbird diaphragm valves that would make today's irrigators say "Huh?" ~ I speak of the "Fluid Resistor"
I still have a ton if those in stock. Back in the day I used to tear down and rebuild brass RB valves on a regular basis!
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  #24  
Old 07-29-2014, 03:22 PM
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I didn't have too many to deal with. I know the first time I brought a diaphragm assembly to a job, was the first time I learned that there was a change in the design of the RB brass valve that made the part I brought with me unfit for the job. I know I spent some minutes looking at the two diaphragm assemblies, wondering what the design change achieved besides royally ticking me off.
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  #25  
Old 07-29-2014, 03:41 PM
SoCalLandscapeMgmt SoCalLandscapeMgmt is online now
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Originally Posted by Wet_Boots View Post
I didn't have too many to deal with. I know the first time I brought a diaphragm assembly to a job, was the first time I learned that there was a change in the design of the RB brass valve that made the part I brought with me unfit for the job. I know I spent some minutes looking at the two diaphragm assemblies, wondering what the design change achieved besides royally ticking me off.
Revenue increasing strategy for RB. It meant that you had to stock TWO different diaphragm assemblies and RB sold twice as many diaphragms!
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  #26  
Old 07-31-2014, 07:47 PM
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Ron Wolfarth Ron Wolfarth is offline
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Maximum Wire Runs

Why does water pressure influence the maximum wire run on a valve zone?

In the charts Rain Bird provides customers that show the maximum wire run for different size wires there are multiple tables with the only difference being the water pressure at the valve. It is not very intuitive that water pressure would have an effect on electrical performance.

When electricity is provided to the valve solenoid, the coil in the solenoid creates a magnetic field that magnetizes the metal core in the middle of the coil. This magnetized core acts on the metal plunger pulling it up off its seat where it has acted like a drain plug in a sink of water because, like our residential valves, our solenoids are ‘reverse flow.’ This means that the ‘plug’ is on the upstream side of the drain.

In a sink of water, the deeper the water, the harder it is to pull the drain plug off the seat. The weight of the column of water above the plug is pushing against it. More work is required to lift that heavier column of water.

The same thing happens in the solenoid. The more water pressure, the more pulling force is needed to pull the plunger off its seat.

As water pressure increases, a stronger and stronger magnetic field is required. This is where the length of the wire run becomes a factor. The maximum wire run is determined by the minimum voltage required to operate the valve. We run tests to determine that minimum voltage. At higher water pressure, more voltage is required because a stronger magnetic field is required. The minimum voltage needed to operate the valve is reached in shorter wire length runs. Larger wire results in longer runs because there is less voltage drop in larger wire.
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  #27  
Old 08-01-2014, 09:18 AM
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Sprinkus Sprinkus is offline
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Remember this from our good friends at WM? No other company that I contacted was willing/able to provide this information.

Solenoid Inrush Measurement

Inrush Current. It is the current required to generate sufficient magnetic force to pull the plunger or overcome the air gap.

If there is any fluid inside the solenoid, the air gap is filled with water which exerts certain amount of pressure on top of the plunger.

We need to know what is the force/pressure exerted on top of the plunger .

F1=P/A

P=water pressure
A= Area of the Plunger where water pressure is exerted.

F1= Force on top of the plunger.

Now the Magnetic force required to pull the plunger is
F= F1+FP

FP= is the weight of the plunger.

Based on the net force, which is the required magnetic force, use Maxwell force formula:

F = ( Fm)2 μ0 A / (2 g2)

In order to calculate this, you should know the magnetic permeability of the solenoid, material, number of turns in the coil, cross section of the coil ,or the magnet wire Inductance,etc.

The INRUSH does depend on the water pressure and efficiency of the solenoid.
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  #28  
Old 08-01-2014, 10:30 AM
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Ron Wolfarth Ron Wolfarth is offline
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Quote:
Originally Posted by Sprinkus View Post
Remember this from our good friends at WM? No other company that I contacted was willing/able to provide this information.

Solenoid Inrush Measurement

Inrush Current. It is the current required to generate sufficient magnetic force to pull the plunger or overcome the air gap.

If there is any fluid inside the solenoid, the air gap is filled with water which exerts certain amount of pressure on top of the plunger.

We need to know what is the force/pressure exerted on top of the plunger .

F1=P/A

P=water pressure
A= Area of the Plunger where water pressure is exerted.

F1= Force on top of the plunger.

Now the Magnetic force required to pull the plunger is
F= F1+FP

FP= is the weight of the plunger.

Based on the net force, which is the required magnetic force, use Maxwell force formula:

F = ( Fm)2 μ0 A / (2 g2)

In order to calculate this, you should know the magnetic permeability of the solenoid, material, number of turns in the coil, cross section of the coil ,or the magnet wire Inductance,etc.

The INRUSH does depend on the water pressure and efficiency of the solenoid.
Excellent!
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  #29  
Old 08-01-2014, 10:50 AM
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Wet_Boots Wet_Boots is online now
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I think you can even up those equations to include the characteristics of the fluid the solenoid is operating with.

Now, is it true that a valve tip from several decades ago might read "Don't connect the Thermal Hydraulic valve wires to line voltage?"
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  #30  
Old 08-01-2014, 11:00 AM
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TH Valves

Quote:
Originally Posted by Wet_Boots View Post
I think you can even up those equations to include the characteristics of the fluid the solenoid is operating with.

Now, is it true that a valve tip from several decades ago might read "Don't connect the Thermal Hydraulic valve wires to line voltage?"
Only if the wire gauge was as big as your little finger!
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