I noticed a lot of interest in my sprinkler timer review post and I wanted to expand on that a bit. In this post I’ll tear apart the Vigoro 3015V Sprinkler Timer and see what inside of it and makes it work. This timer has worked reliably for me, but I switched to the Orbit multi-zone sprinkler timer system so this unit was spare. I can’t resist opening up stuff and checking it out. Please read through the post and post a comment if you like.
The Vigoro 3015V sprinkler timer is a single-zone outdoor unit which connects directly to your outdoor hose lines and has an option for a remote water sensor unit which is attached to a receiver. The case is glued, or more likely ultrasonically welded closed around the internal components.
If you want to see large versions of these images just click on the image in the page you can use the << and >> button at the bottom of the image viewer to move between photos.
The first step in opening the case is to pull out my trusty craftsman moto-tool and cut carefully through the seam of the box. I wore safety glasses for this as hot plastic gets thrown all over the place.
I didn’t want to cut through the valves or through the plug for the water sensor receiver antenna, so I used a screwdriver just to pop the remaining edges of the seams. It came apart pretty easily.
With that done we can now see the internals of the Vigoro 3015V sprinkler timer and get an idea for how they do things. I’ve labeled the different components inside of the housing. You can see the battery terminals, Rain Sensor Antenna connector (mislabeled as ‘temp sensor’, the water valve and in the bottom of the shell you can see the ‘potted’ electronics section with the battery terminals going into it. The potting materials are usually an epoxy type material which is designed to completely seal the electronics and protect them from any moisture damage.
I disconnected the valve assembly for a closer look as seen in this next picture on the right hand side. The valve has a long barrel section which looks something like a rifle scope, and attached to the left hand side with the red and black wires is the drive motor and gearing.
Here’s a side view of the valve. You can see the drive motor a bit more clearly as well as the one of the gears that it moves. The gearing moves a pin in and out of the valve housing to start and stop the flow of water.
This picture below is the top view of the valve labeled and colored to show the high and low pressure side. The high pressure side from the water inlet comes in from the right and co-axially surrounds the low pressure section which goes to the outlet.
I removed the motor from the valve and you can see a bunch more labels. Of note you can see the high and low pressure taps, and the return spring in the middle. When the pin slides out it connects the high pressure from the high pressure tap to the low pressure tap, causing the main high pressure to compress the spring and open the valve. A more detailed pictorial sequence is further down in this post.
This is the main valve drive motor for the Vigoro 3015V sprinkler timer. It consists of a small DC motor and a gear drive with a cam on it. as the motor rotates (rather quickly) it presses the pin in, or pulls the pin out. When the pin is extended the pressure behind the valve diaphragm equalizes and the spring forces the diaphragm closed. When the pin slides out, the opposite happens.
Below is the valve body with the diaphragm removed. If you look at a large version of the photo you can see how there is an outer cavity where the high pressure water comes in from your home and then an inner cavity which is the low pressure/outlet side of the valve.
In the next 3 images you can see a diagram I drew of the valve in the Vigoro 3015V. This is the sequence of the valve opening. Closing the valve works in reverse.
I hope this helps anyone who was curious about how these valves work. There is a gate, but it’s very small and basically acts as a hydraulic switch to operate a larger hydraulically operated valve. It’s kind of neat for me as I’ve always wondered how these things work, and it took me a little bit to figure out how the thing worked. I was expecting to see a large gate with a motor that open and closed it. I think the Orbit valves may work like this, and I am going to be dis-assembling one of my spare valves from my Orbit Sprinkler Timer at some point this week.
Please let me know if you have any questions or comments or corrections by filling in the comment form at the bottom of the page.