Step 4: Build The Trigger Valve Assembly

In this step we will modify an Orbit Model 57461 1" jar top sprinkler valve, making it a pneumatically actuated trigger valve. I found this particular model to have a number of advantages. It is the cheapest 1" valve I've found. The air valve is installed in the center of the cap allowing easy orientation of the trigger. Finally, the "jar top" construction makes it extremely easy to work on. Here is a link to a page devoted to modifying this exact valve, I left out the safety ball valve in this design. Here is a link to a visual explanation of how the sprinkler valve works.

Trigger Valve Supplies
1 Orbit Model 57461 1" sprinkler valve
1 Blow gun or similar
1 1/4" NPT pipe/hex nipple, like this
Teflon tape
Dremel or drill

  • Remove solenoid and bleed screw, they will not be needed Fig 1. Save the solenoid for future diabolical inventions.
  • Disassemble valve by unscrewing the "jar" ring. Be careful, as under the top is a spring under tension.
  • Cut, grind, or drill out the center of the top, make sure to leave enough plastic to thread the 1/4" NPT fitting into Fig 2. Grind or cut down the lip of material around the center hole to the level of the ribs Figs 3 & 4. This will allow you to get the fitting deep and tight.
  • Use the 1/4" NPT fitting as a tap for cutting threads into the hole you just made, try to keep it as perpendicular as possible Fig 5.
  • Once you have the threads cut, put Teflon tape on one end of the fitting and thread that into the blow gun Fig 6. Apply some thread locker to the other end of the fitting and tighten the whole assembly into the valve top.
  • You are now ready to epoxy three places. A little dab in the bleed screw hole in the top, a little dab in the bleed hole at the valve outlet, and a good bit of epoxy around bottom and top of the brass fitting Figs 7 & 8. Try and leave the wrench flats of the fitting exposed and epoxy free in case you need to remove the blow gun at some point.
  • Let the epoxy dry and then reassemble valve. The lever side of the valve should be underneath the outlet of the valve. Make the securing ring is as tight as possible.
Stinkfist092 years ago
Yea when you blow thru the metal tube it comes the square opening i'll epoxy it and try it out.Thank for the help crispyjones.
Stinkfist092 years ago
heres some pics like i said same exact model # and everything
missy 4490.jpgmissy 4493.jpg
crispyjones (author)  Stinkfist092 years ago
It looks like they just changed the casting/design a bit. I bet if you blow in that metal tube in the top picture the air will come out the notch you can see in the lower one. If that is the case then you have found the bleed. The idea is to simply plug this passage, drop some epoxy in the notch, or in the tube, anything to keep the air from going through.
Stinkfist092 years ago
Can someone help me with the sprinkler valve? attempting to make this with my son. i brought the valve home opened it up and noticed the hole you have to epoxy inside is not there like in fig. 7 just a square opening no bleeder hole on top and the valve is the same model number as in the pics.
what does thread mean? sorry. im young
arty8173 years ago
When i blow into the sprinkler valve AWAY from the presure chamber by the arrows it still lets air come out and when i pull the blow gun it lets a bit more air than there already is! do you now why?
dremeldude4 years ago
if you wanted the trigger to be more accessible you could substitute the nipple for two barbs and hose.
Iwanna b4 years ago
Your link to a blowgun sent me to a website, but there are many choices there, which one is the one I should buy?
I did everything you said to do with the Trigger Valve System but when I put air inside the chamber is leaks out of from that hooks to the tennis ball attachment and also when I press the blow gun it does nothing. What am I doing wrong?
Never mind about my question. I put the wrong end towards the pressure chamber (the arrows were pointing toword the pressure chamber).
Kantor5 years ago
would heavy duty liquid nails be a good epoxy??
crispyjones (author)  Kantor5 years ago
I doubt it. I know they sell some different versions of the product, but the ones I've seen don't look suitable.
in figure 7 on the left, do i need to epoxy the gap below the hole? i epoxied the hole and tested it out but it seemed to leak
crispyjones (author)  ducktapeman555 years ago
The gap below that hole doesn't lead anywhere.  That hole is connected to the thin metal pipe that serves as the guide rod for the diaphragm.  I would pressurized the valve and put it underwater, bubbles will make it obvious where the leak is coming from.  If the water test confirms you have a leak there, just fill the metal pipe with epoxy and you will be sealing the same passageway.
iTinkers5 years ago
Is there any reason you could not use a solenoid valve for the trigger rather than the sprinkler valve? I'm interested in making this, but it seems it'd be much simpler to use a NC solenoid valve. Is there a practical reason not to? I'm looking at a few online that are 1/4 NPT, 12V. 0-150PSI. Says they are "fast acting" even though the exact times are unknown. Seems they'd be perfect for this project and much simpler to use. Am I missing something though?
crispyjones (author)  iTinkers5 years ago
I am pretty sure you won't get the necessary air flow through a 1/4" NPT orifice. You could skip step 4 and leave the sprinkler valve unmodified with solenoid in place. Check step 7 in this instructable for some more detail on a trigger circuit. The valve probably won't open as fast as one modified with a blow gun, but it might be acceptable.
GianniMora5 years ago
can i use j.b. weld
crispyjones (author)  GianniMora5 years ago
I used a two part epoxy so it would flow into the holes in the valve, and around the threads of the coupler. J-B weld doesn't flow, so you will have to force it somehow, possibly leaving voids were air can escape.
ok thx
ome336 years ago
I was going to use a ball valve instead of a sprinkler valve thus eliminating the need for a blow gun.............how would i install this
gjjones1256 years ago
I don't understand step 4 are you actually cutting threads, as in making your own? How do you do that? Sorry I am building it but I'm kind of a noob (although I have tons of experience with PVC).
crispyjones (author)  gjjones1256 years ago
Yes, you use the metal fitting to cut threads in the plastic. The hardest part is getting the first turn into the plastic. As you tighten the fitting (with a wrench or socket) it will cut its own threads into the plastic.
tk47176 years ago
The only Sprinkler valve I could find at home depot was Orbit model 57101. It's still 1" but is slightly different. Can this valve still be used, if so, what mods do I have to make to these instructions?
tk4717 tk47176 years ago
never mind... I monkeyd it into working - if anyone else has the same issue, let me know and I'll give you some hints.
bricez28 tk47176 years ago
i have the 57101 as well, howd you get it to work?
qwertyboy6 years ago
no! don't throw away that perfectly good solenoid! put it in your junk box that way if you need a solenoid, you have one.
treinengek6 years ago
why don't you use the solenoid as trigger its powerful enough for the pressure and a circuit can be made
cowboy936 years ago
i have access to a welder so would it be better to make the pressure chamber out of metal pipe then out of pvc
Where did you get the pressed air to fill the chamber?
efrenba6 years ago
Hi, What's the function of the sprinkler valve, it lets the air to pass completely or only a fraction through it?
Didrtan6 years ago
does the blow gun need the rubber tip?