How do solenoids work?

[Student Of Life]

How do solenoid valves work when integrated into a pump system? So I have a pump sitting at the bottom of a reservoir, plugged into a timer, running water into a 1" mainline that splits into 3 separate 1" lines (one per 4x8 table), and these lines have octabubbler-style manifold heads on them. I'd like to incorporate solenoid valves to remove any siphoning/backflow, as well as have more control over the irrigation (watering one table at a time, for example). How would I go about this?

 

[I'mback]

Solenoid energizes, opens up the valve. You would need a multiple timer. e.g one that wilol permit more than one cycle. e.g table 1 for 10am x 10 min, table 2 for 11am, and so on and so forth.

 

[Student Of Life]

Solenoid energizes, opens up the valve. You would need a multiple timer. e.g one that wilol permit more than one cycle. e.g table 1 for 10am x 10 min, table 2 for 11am, and so on and so forth.

I have a pretty good timer, will allow 8 waterings per day, but I'd need a better one for sure. My question is more about how to physically install them, make them connect with the pump (since they seem to have no 'plug', just wires), how to get the pump to communicate wit the irrigation master controller, etc.

 

[AgentPothead]

You'll have to be more specific, when you say solenoid do you mean one already fit to a pipe like

Or do you mean a bare solenoid like

I'm assuming valve like the top one? Cause that you just plumb into your system setup to the same timer as your pump so that it opens and closes based on the pump turning on/off. You'll need to determine if you have a NC or NO valve which is normally closed or normally open and go from there. You want the valve open when the pump is on and vice versa so I'd go with a NC valve if you haven't bought one yet. That way you can just turn it on when the pump turns on. With a NO you'll need to invert that signal somehow. That's if you will have a pump for each valve. If you will only have 1 pump for multiple valves you will have to do something more in depth and it will depend on exactly what you wanna do I think. If you really wanna control multiple valves with 1 pump I might recommend looking into a microcontroller based solution.

 

[I'mback]

I have a pretty good timer, will allow 8 waterings per day, but I'd need a better one for sure. My question is more about how to physically install them, make them connect with the pump (since they seem to have no 'plug', just wires), how to get the pump to communicate wit the irrigation master controller, etc.

If you tell me EXACTLY what you are trying to achieve (e.g what your set up is) I can more than likely tell you how to go about it.

 

[Student Of Life]

When you say solenoid do you mean one already fit to a pipe?

If you will only have 1 pump for multiple valves you will have to do something more in depth and it will depend on exactly what you wanna do I think. If you really wanna control multiple valves with 1 pump I might recommend looking into a microcontroller based solution.

Yes, I assume this is what I want. I'll explain below.

If you tell me EXACTLY what you are trying to achieve (e.g what your set up is) I can more than likely tell you how to go about it.

I currently have a mondi gold pump plugged into an 'ACDT-20' timer. The pump is sitting at the bottom of a res and is connected to a 1" PVC pipe. This pipe heads over to the three 4x8 tables in the room, and T's off at each table, shooting off a new 1" line down the length of each table. There are two 'rainbird' 8-port manifolds per table, so one per light.

What I want to do is be able to feed each table on it's own time frame, so that thirstier strains can drink more often throughout the day. Currently, I have to fiddle with the output of each individual emitter so that 60 seconds of irrigation means 100mL for some strains, and 250mL for others since the entire garden is getting irrigated through the same pump and timer. It's irritating. I'd rather have each 4x8 table be it's own irrigation 'zone', and plants on table 1 will get 100mL 5x a day, while plants on table 2 will get 100mL 2x a day.

I believe solenoids will also solve one of the issues with my current setup, and that is siphoning. A few of the plants will flood every watering, despite there being a hole drilled into the 1" line inside the res. I believe this can be fixed easily, by either putting the hole at the pipe's highest point (with tubing leading back into the res), or installing some sort of valve that allows air into the line, but doesn't let water out, to break siphons.

The siphoning is just the secondary thing though. It's mainly an itch to learn how to better control my environment, to expand my skillset and have a better system in place. Irrigation is something I've tended towards avoiding usually, as it's been the most intimidating. I don't want that to be the case anymore. Let me know if you want me to draw anything out to the best of my ability in case the text is hard to understand.

 

[I'mback]

Solenoids open and shut, therefore there should be no siphoning.

I'm a control tech... without knowing some of the basics or your set up and controllers, it is difficult, even with the latest blurb.

Hot water baseboard heating = one furnace (reservoir) multiple zones (living, sleeping, basement) The cicr pump runs 24/7. Which ever zone needs heat (via thermostat) that zone and that zone only will get heat. The solenoid allows hot H2O to the zone, once the thermostat is satisfied, the solenoid closes. In this secnario, there is 3 thermostats. One for each zone. 3 solenoids, one for each zone and one circ pump/reservoir.

You will need to tell your controller where you want the extra H2O. That cannot be accomplish on a single timer. It could be done, but that MOFO is going to cost you mucho dinaro. e.g more than purchasing 3 timers to open individual solenoids.

So your reservoir pump circulates the water min the reservoir but dead heads at the solenoids. Good you have a constant supply system.

You need power going to 3 different timers which in turn controls table a, b, and c. The length of time they are (solenoids) energized is when the timer sets them off and, for the duration you preset. The power from the timer is going to the appropriate table solenoid.

 

[GOT_BUD?]

Solenoids open and shut, therefore there should be no siphoning.

I'm a control tech... without knowing some of the basics or your set up and controllers, it is difficult, even with the latest blurb.

Hot water baseboard heating = one furnace (reservoir) multiple zones (living, sleeping, basement) The cicr pump runs 24/7. Which ever zone needs heat (via thermostat) that zone and that zone only will get heat. The solenoid allows hot H2O to the zone, once the thermostat is satisfied, the solenoid closes. In this secnario, there is 3 thermostats. One for each zone. 3 solenoids, one for each zone and one circ pump/reservoir.

You will need to tell your controller where you want the extra H2O. That cannot be accomplish on a single timer. It could be done, but that MOFO is going to cost you mucho dinaro. e.g more than purchasing 3 timers to open individual solenoids.

So your reservoir pump circulates the water min the reservoir but dead heads at the solenoids. Good you have a constant supply system.

You need power going to 3 different timers which in turn controls table a, b, and c. The length of time they are (solenoids) energized is when the timer sets them off and, for the duration you preset. The power from the timer is going to the appropriate table solenoid.

Would it be useful to route a return pipe from the last table so the pump isn't building pressure within the system when all the valves are closed?

I just started a job as a HVAC control tech myself, and am still learning how everything works. But have been working in low voltage in one form or another for 28 years.

 

[PurplePotion]

Would it be useful to route a return pipe from the last table so the pump isn't building pressure within the system when all the valves are closed?

I just started a job as a HVAC control tech myself, and am still learning how everything works. But have been working in low voltage in one form or another for 28 years.

I think I would definitely plumb a return line with both a solenoid and manual shut-off valve/flow regulator to give yourself flexibility down the road. Also, install manual shut-offs and some type of bleeder valve(especially important for constant pressure systems/blumats) everywhere and anywhere you could imagine having to “work on” or clean while the system is in use, I.e. before and after your filters. Unions/swivels are your friend.
1. Empty lines after watering cycle
2. Flush lines (maintenance)
3. Purge air out of a constant pressure system
4. Maintain even temp/avoid stagnation in constant pressure system— this is where I could see restricting the flow (barely opening the manual shut-off) so that there is a constant fresh flow of nutrient solution readily available in the lines at all times.


Note: when I refer to constant pressure systems, I’m really thinking of Blumats, but I’m sure there are other systems that work similarly off of moisture sensors, etc. I’m finding that with a warm room, enough black drip line and plants that aren’t drinking fast enough, there is a difference in the input and output temp of the nute solution coming from the blumats.

/endramble

 

[Student Of Life]

Solenoids open and shut, therefore there should be no siphoning.

I'm a control tech... without knowing some of the basics or your set up and controllers, it is difficult, even with the latest blurb.

Hot water baseboard heating = one furnace (reservoir) multiple zones (living, sleeping, basement) The cicr pump runs 24/7. Which ever zone needs heat (via thermostat) that zone and that zone only will get heat. The solenoid allows hot H2O to the zone, once the thermostat is satisfied, the solenoid closes. In this secnario, there is 3 thermostats. One for each zone. 3 solenoids, one for each zone and one circ pump/reservoir.

You will need to tell your controller where you want the extra H2O. That cannot be accomplish on a single timer. It could be done, but that MOFO is going to cost you mucho dinaro. e.g more than purchasing 3 timers to open individual solenoids.

So your reservoir pump circulates the water min the reservoir but dead heads at the solenoids. Good you have a constant supply system.

You need power going to 3 different timers which in turn controls table a, b, and c. The length of time they are (solenoids) energized is when the timer sets them off and, for the duration you preset. The power from the timer is going to the appropriate table solenoid.

I don't know how I can be more clear. I've listed the exact equipment I currently use, and said exactly what I want to do instead of what I'm currently doing. Here's a quick reference video that hopefully makes things more clear. He explains the irrigation system at around the 3 minute mark of the video.

https://www.youtube.com/watch?v=i7IallzDQME

Essentially the last stage in their irrigation system is what I'm looking to achieve. Sending mixed nutes through zone-designated lines at different times, full customization. I know that they can send them to different tables at different times because in one of their more recent posts on ig, one of them said something about 'some plants need 100mL 2x a day, others need it 8x a day'.

I suppose it's possible that they have many rooms per facility, and each room is it's own 'zone', but this would be similar to my goal anyway, just replace the idea of a room being a zone with a table being a zone.

I'm trying to understand your post but it's a bit cryptic tbh, not well spelled out for beginners like me. No disrespect, and maybe it's my lack of irrigation knowledge, but I just can't make it out.

I've messaged a few irrigation companies, and my request made much more sense to them. I've been recommended a station controller/solenoid/pump start relay combination so far. Seems to make sense, but I'm still looking into the pump start relay.

 

[I'mback]

The furnace part is a metaphor. Your question wasn't clear neither. The video shows an expensive system, something you did no mention cost. Most like to keep cost down. I KISSEd it!

 

[GOT_BUD?]

Solenoids open and shut, therefore there should be no siphoning.

I'm a control tech... without knowing some of the basics or your set up and controllers, it is difficult, even with the latest blurb.

Hot water baseboard heating = one furnace (reservoir) multiple zones (living, sleeping, basement) The cicr pump runs 24/7. Which ever zone needs heat (via thermostat) that zone and that zone only will get heat. The solenoid allows hot H2O to the zone, once the thermostat is satisfied, the solenoid closes. In this secnario, there is 3 thermostats. One for each zone. 3 solenoids, one for each zone and one circ pump/reservoir.

You will need to tell your controller where you want the extra H2O. That cannot be accomplish on a single timer. It could be done, but that MOFO is going to cost you mucho dinaro. e.g more than purchasing 3 timers to open individual solenoids.

So your reservoir pump circulates the water min the reservoir but dead heads at the solenoids. Good you have a constant supply system.

You need power going to 3 different timers which in turn controls table a, b, and c. The length of time they are (solenoids) energized is when the timer sets them off and, for the duration you preset. The power from the timer is going to the appropriate table solenoid.

I'll just plug this into a translator

your irrigation system = reservoir running to multiple zones (table 1, table 2, table 3) The pump runs 24/7. Which ever table needs water that table and that table only will get water. The solenoid allows water to flow to the table, once the timer runs out, the solenoid closes. You'll need 3 solenoids with 3 timers.

OR

You can purchase a controller to replace the 3 timers. But that will cost considerably more money and you'll still need to buy the solenoids.

Most water solenoids I've seen run on 25 volts. So you'll need a 25 volt power supply for each solenoid. That power supply will plug into a timer that you set to turn on for x amount of time, y number of times per day.

 

[Student Of Life]

The furnace part is a metaphor. Your question wasn't clear neither. The video shows an expensive system, something you did no mention cost. Most like to keep cost down. I KISSEd it!

I appreciate the help. It's just I'm too limited in my understanding to grasp your post. I'd like to keep cost down too, but more than that, I'd like to have an irrigation system that works and works well.

Most water solenoids I've seen run on 25 volts. So you'll need a 25 volt power supply for each solenoid. That power supply will plug into a timer that you set to turn on for x amount of time, y number of times per day.

Thanks man. So the irrigation companies I've contacted have recommended the previously mentioned pump start relay-->irrigation controller-->solenoid system, which sounds like what you're talking about, right? Where does the pump come into the picture for you?

 

[I'mback]

Google is your friend! Do9n't limit its search to what you are doing. Computus says 1+1=2 if you are looking for a different answer + 0

 

[f-e]

The siphon issue is, as you say, a case of letting in air where your pipe comes over the edge of your barrel. Often pumps can only push the water up a few feet, so that air hole can be extended with another bit of pipe, to a point so high the pump can't get water out of it.

I think you should buy 3 pumps. Leave the solenoid valves for people well past knowing how to fit a plug.

Once you figure out how to fit a plug, you could use one to stop the siphoning effect. You would just put the valve in the pipework, and plug it in with the pump. Then when the pumps on, the valve is open.. pump off.. valve shut.

Now the thought provoking bit. All water that has passed your anti siphon point, will want to leave by the lowest drip emitters, until the only water left in the system is lower than the lowest emitter. Many people run there manifolds too high, so they empty many liters out of the lowest emitters. Your manifolds should be lower than your emitters, so the only pipework higher than the emitters is the drop from your barrel. A couple of foot of 1" pipe. Still a few liters.

1" pipe... What are you watering. That's thousands of drippers. You can get a lot through a normal garden hose of 1/2" and there are soooooo many valve choices. $2 gets a 12v one, and you seem like 12v is about where you are at. All my trickery&magic is 12v. It keeps me alive. Maybe your first venture is an anti siphon vent, using 1/2" hose, and a 12v washing machine solenoid valve to open and close it. Obviously a 12v psu will be needed. Then a method of ensuring either the pump runs, or the valve is open. Some cheap contactors have day and night leads. To achieve this 'one or the other'

 

[RichFromTheSun]

In the system you saw in the video, there are no timers for the pump; they are activated by pressure switches. The pumps are always "on," but not always pumping water. They only pump water when the pressure in the line drops because a valve is opened, aka a pressure switch. Think of it like a faucet in your house. You open the faucet, and water comes out. You close the faucet and the water stops.



You control the solenoid valves with a controller, like a Toro. In your example, you would have three valves, each representing a zone. Zone 1 opens for X seconds, the pump senses the pressure drop, and begins to pump water until the valve is closed. It then senses the increased pressure and stops pumping water. Zone 2 opens for Y seconds and then closes, and so on.



PM if you have more questions.

 

[CrushnYuba]

I think we are talking 24vac solenoid valves right? Not dc latching type?

Whatever controller you have will have a pump start relay socket. It may be labeled master valve. It will be 24vac out. You will have to use a pump start relay with it. It's just a 15$ 24vac relay.

Alternatively, you can put your pump on a pressure switch with a small pressure tank. Or a cheap pump with a switch built in. When the valve opens, it will turn the pump on. The whole thing stays under pressure like your home if you are on well water.

Keep in mind solenoid valves need a certain amount of pressure to open and close. The solenoid does not open or close valves. The water pressure does. The solenoid just directs directs the water. So they should be sized appropriately. Many are adjustable. Just because you have 1" pipe doesn't mean you need a 1" valve. 3/4 may be more appropriate. If you don't have enough pressure, it won't open the valve. Or even worse, it won't close the valve! I use 1" valves with a 10+ gpm water source. I bet you are using more like 3gpm for one off those tables.

Don't let it overwhelm you. Most of this stuff can be gotten from home depot really cheaply. Most likely you will be spending less then 100$ for a few valves and controller.
You can get a 7 zone controller for about 50$. Solenoid valves for about 12$.

I could help you design a system but you need to describe your water usage per zone better.
A simple 5$ flap check valve will prevent siphoning back.

Also, if you want i can take some pictures of the way my valves are plumbed on one of my setups.

 

[CrushnYuba]

That is the inside of a 50$ orbit controller.

See how there is the spot labeled "pump". Sometimes it's labeled master because it can also be used for a master valve. There is also outputs for 12 garden zones. Any time a zone gets watered it also sends power through the pump hookup. The pump output id's 24vac like your valves. Your pump is 110vac. So You connect the pump start relay to the pump output on your controller. You plug your pump into that.

 

[CrushnYuba]

If you just walked into your local ace hardware store and asked for an underground sprinkler valve and controller, you would get further.

It's crazy that solenoid valves are used for sprinklers and agriculture everywhere but indoor growers and icmag don't know what they are.

How do you think lawns are getting watered? Any time you see one of those little pop up sprinklers at a hotel, office building, park, golf course, a solenoid valve it's turning it on. If a human isn't doing it manually, it's a solenoid valve.

I have them in my yard for watering my lawn. I got them in my outdoor gardens and greenhouses. My fruit trees on drip.

 

[f-e]

I use one like you would find in a washing machine. Only 12v, from China, for a couple of quid. I use it, as washing machine parts are readily available. It fills my tank, used in conjunction with a float switch. The household plumbing has had the washing machine tap fitted. Washing machine hose reaches the washing machine valve. Which is over the tank, with a hose dropping into it. It's filled just after the drip pump is done. It takes a few mins, so the timer involved runs for that time, plus a few more mins. Time to fill to the float, but if the float did fail, the power is cut soon after anyway. I don't just have a timer, 12v psu and the valve + float switch. I have unloaded the float switch with a 12v relay. It was rated high enough to switch the valve, but I decided it better to just switch a relay. The relay then working the valve. It's quite simple really. The drip pump runs for the same time each day, so the volume of water to fill it back up is the same each day. So the feed and acid requirements the same. So if your keeping up, you can see where this is going.

There are lots of solenoids in play here. It's just not a common subject.