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1

Thursday, June 2nd 2016, 9:16am

Toro 200-0-1 hydraulic valve not closing

I have a somewhat ancient system. FIRST: it has a backflow preventer/vacuum breaker.
When the hydraulic clock died I replaced it with an electrical controller and a electro-hydraulic converter which works just fine. Everything worked well last year. I live in Michigan and have the system blown out every fall.
This year zone 8, a drip zone, does not shut off. All other zones do.
If I shut off the main line supply at the backflow preventer, sometimes the valve closes after 10 min, sometimes not.
Water supply is from a well. The converter has an inline filter on the input and does have a drain.
The zone control valve is a Toro 200-0-1. Before I replace it (the valve box was placed so most of the valve shows, but not the inlet pipe so replacement will be a major digging job, it is 2' under grade) I would like to verify that it needs replacement.
From playing with it it seems that the controller valves are normally closed and release pressure from the control tubing when the zone goes on. If that is true it would seem that I can test the valve by disconnecting the control tubing (which should turn the zone on) and then putting my finger on the control inlet barb should shut it off. Is that correct?
Is it worth replacing the diaphragm (which I probably could do without digging up the yard)?

Any other diagnostic suggestions?
Thanks in advance

bill

Wet_Boots

Supreme Member

Posts: 5,198

Location: Metro NYC

2

Thursday, June 2nd 2016, 10:12am

That valve cannot be serviced. If the control tubing is intact (pressure test it) then you could connect another hydraulic valve downstream of the first one and move the control tubing from the old valve to the new one.

The part number you gave doesn't quite make for an exact fit. Is there a supply tube for the convertor? Do you have the old controller around, to give us the exact part number (what model it is doesn't matter as much as the hyphenated part number)

3

Friday, June 3rd 2016, 6:33am

From the first post: Water supply is from a well. The converter has an inline filter on the input and does have a drain.
How would one pressure test the control tube ?
The controller (clock) died 5 years ago and even memory of it is faint.
Back to the question of how the hydraulic valves work. The electro-hydraulic converter has a filtered supply and a drain.
Does putting pressure on the supply or releasing pressure turn the valve on.
Because the valve replacement (250-0-1) is listed as NO I suspect that pressure closes the valve.

Wet_Boots

Supreme Member

Posts: 5,198

Location: Metro NYC

4

Friday, June 3rd 2016, 8:33am

the filtered supply to the converter (or to a hydraulic controller) indicates normally-open hydraulic valves - this sort of valve requires water pressure in the control tube to close the valve (hence the supply) - the controller served to remove that supply pressure from a selected zone, letting it bleed off from the drain

this means you can remove the tubing from that difficult-access valve and install another valve downstream of it

testing the valve independent of the controller requires some additional control tubing and a source of pressure to apply through it

checking for a faulty control tube might be as simple as switching tubes between two adjacent valves in that valve box

5

Saturday, June 4th 2016, 6:27am

Thank you.
Of course, it can't be simple, there is only one valve in that box.
Later today I am going to try applying pressure from a hose-end drip regulator (20 psi).

bill

Wet_Boots

Supreme Member

Posts: 5,198

Location: Metro NYC

6

Saturday, June 4th 2016, 7:05am

You need more pressure in the control tubing than in the supply for the sprinkler system. Some of these systems ran on pumped water, with city water supplying the controller. No worries if the control pressure is greater than the sprinkler supply pressure.

7

Sunday, June 5th 2016, 5:12am

You need more pressure in the control tubing than in the supply for the sprinkler system. Some of these systems ran on pumped water, with city water supplying the controller. No worries if the control pressure is greater than the sprinkler supply pressure.
Ah ha. I have "progressed" to the point that multiple zones are taking turns not quite shutting off. I shall pursue the supply to the controller.

8

Monday, June 13th 2016, 6:42am

Solved

I pulled the supply (pressure) line to the electrohydraulic converter and the pressure and flow were good.
I pulled the drain line from the converter and the pressure and flow were good from the converter drain port.
Wait !
The drain line is only supposed to collect the few drops released when a valve control line is switched from pressure (off) to no pressure (turn valve on) and I had a constant stream of water from the drain port. This is not good.
After considerable playing with the converter I discovered that two of the valves of the 16 on the converter were bad. The converter works by having the 24V signal from the controller energize a solenoid that switched the hydraulic control line from pressure to drain. In my case, when two of the valves were in the deenergized position the pressure supply was connected to the drain directly. This is not good.
The result was that the pressure from the pressure line was low and the pressure in the drain line was much higher than it was supposed to be: none. This resulted in a couple of the sprinkler control valves staying partly open, my original complaint.
Removing the bad converter valves from use (I have spares on the converter) and manually turning them to "on" fixed the problem.

Many thanks and much appreciation to Wet_Boots for the education and suggestions :)
bill

Wet_Boots

Supreme Member

Posts: 5,198

Location: Metro NYC

9

Monday, June 13th 2016, 7:11pm

Glad it worked out. The constantly-running drain was a key clue.

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