You are not logged in.

Dear visitor, welcome to SPRINKLER TALK FORUM - You Got Questions, We've Got Answers. If this is your first visit here, please read the Help. It explains how this page works. You must be registered before you can use all the page's features. Please use the registration form, to register here or read more information about the registration process. If you are already registered, please login here.

pacstud

Unregistered

1

Saturday, July 11th 2015, 7:06pm

Replacing Nelson 7904 Valves

I have valves that either are, or are going to be, shot.

Had to emergency replace one, local irrigation company gave me irritrol 205t.

Should I swap any other valves out with this, or is there a better option?

pacstud

Unregistered

2

Saturday, July 11th 2015, 7:15pm

Also

I should add some trouble shooting question(s).

Zone won't turn on. New solenoid. Switched with solenoid from other zone, and it's not the controller. I can get zone to turn on if I completely loosen the solenoid. When problem first started, zone was stuck open, and when I took valve apart to clean, now it's stuck closed.

Faulty valve?

Central Irrigation

Supreme Member

Posts: 371

Location: Central Minnesota

3

Saturday, July 11th 2015, 10:52pm

Faulty wiring or controller connection for inoperable zone. See if you have a spare wire in the controller you could use instead. Or perhaps in your attempt to repair the valve, you inadvertantly loosened the selonoid splice.

pacstud

Unregistered

4

Sunday, July 12th 2015, 12:08pm

more info

I think I've eliminated controller issues. I can get the zone open by opening and then closing the bleed valve.

pacstud

Unregistered

5

Sunday, July 12th 2015, 4:43pm

Fixed?

Found a cheap lawn genie diaphragm and it works. Found my old diaphragm was missing the nut at the bottom of the array that held the whole thing together :( So now my next question:

If I am replacing nelson 7904, can I just use irritrol 205 diaphragms? I would rather not buy the whole top cap if I don't need them.

pacstud

Unregistered

6

Sunday, July 12th 2015, 4:46pm

for example


pacstud

Unregistered

7

Sunday, July 12th 2015, 7:51pm

false alarm

I'm not spamming, just an online journal of my failure.

Diaphragm opens, but doesn't close, so no bueno. So now my options appear to be:

1. Replace entire valve, which sucks because I will have to dig and cut pipe.
2. Replace top half, which is way easier but needs to work.
3. Find diaphragm that will work with nelson 7904.

pacstud

Unregistered

8

Monday, July 13th 2015, 9:44am

saga continues

Tiny plastic piece where plunger from solenoid meets valve is missing. I assume this was keeping zone from closing. Swapped tops and bottom of valves appear to be in good order. So I'm back to hoping an irritrol 205 will fit on top of an old nelson 7904.

Wet_Boots

Supreme Member

Posts: 5,269

Location: Metro NYC

9

Monday, July 13th 2015, 12:27pm

Is there some reason you don't simply purchase the correct replacement part?


pacstud

Unregistered

10

Monday, July 13th 2015, 1:00pm

doesn't look right

I am trying to match current diaphragm set up, which involves the 8 screw diaphragm found on the irritrol 205, also some old lawn genies and richtrol (sp.?). I put on new top from irritrol 205 and it works fine. Are those different diaphragms convertible to my valves?

Rate this thread