Help with constant drip. DTW octabubblers

[sheik_yerbouti]

So I've been beating my head against the wall here for the last while trying to stop this constant drip I have here on my first automatic watering irrigation setup.

I'm using 8 port pepco octabubblers with 1/4" drip lines coming off and open on the end. I've taken the rubber gasket out of the bubblers for more even flow as I wasn't getting even distribution to each site. But basically I'm having a hell of a time getting some of the line to stop a constant dripping after each watering. It looks to be the sites that are the lowest in the room as I'm in a basement that has an unlevel slab poured. This is my original set up

Rez, pump, filter, pressure gauge. Pretty simple. Goes into the room

48 sites with 2 lines per site. The bottom right plants are usually the ones dripping.

I thought it was a siphoning problem at first so I altered the setup.

Added a return line to rez (this actually was to keep the pump from cycling on and off as it was reaching its internal pressure switch limit but also figured it would stop siphoning). And added a check valve to hopefully stop the siphoning as well.

Well it didn't stop the drip so I figured it was the water pressure from the tank cause the drip so I changed it up again to this.

So still getting a constant drip. I found that I can stop the drip by lifting the dripping emitter up an inch but that just forces a drip out of another spot. I tried raising the culprit bubbler up in elevation but that doesn't stop it. It's basically dripping out of the few lowest emitters. If I take one out and put if floor level it starts to pour out and stops the dripping from all the others.

So ya, obviously its an elevation thing but is there a way to combat this without trying to get every plant and emitter exactly level to each other?

Hope this makes sense and hope someone can help! Loosing more hair than I need to over this.

Room is looking good either way. Just gotta get this drip thing dialed.

 

[Speed of green]

put the check valve back in. the 1/4" line you ran back to the rez needs to be above water, so when the pump shuts off the line will bring air into the line breaking the siphon.

 

[Speed of green]

there will be a residual about of dripping if your emitters are downhill/lower from your rez & lines, but it shouldn't be constant..

 

[Speed of green]

Put the check valve on the pickup side, in between the res and the pump.

 

[sheik_yerbouti]

Thanks for the reply Speed.

So I was messing around with it last night and when I pull the intake hose right out of the rez the drips immediately stop, and when I put it back in the drips immediately start again so it is definitely a siphoning thing.

Odd thing is that I do have that 1/4" line above water but it doesn't suck air in to break the siphon with the setup I have. If I physically blow into it to force air into the lines it does break the siphon.

I'll try and put that check valve back in to see if it works this time, was odd it didn't work with the last set up I had but hopefully this time it will.

 

[chris harris]

Could you not put a solenoid on the feedline to stop flow, hooked to the timer to open when pump comes on, closes when timer goes off.

 

[sheik_yerbouti]

Could you not put a solenoid on the feedline to stop flow, hooked to the timer to open when pump comes on, closes when timer goes off.

Ya I could. Solonoid and dc transformer were $160 when I looked into it. Plus one more thing to fail. So I'd rather just figure out a way to get the siphoning to stop but it definitely is an option if needed.

 

[chris harris]

Amazon 3/4" solenoid= $20, 12 volt transformer $12, total $32.

 

[sheik_yerbouti]

Amazon 3/4" solenoid= $20, 12 volt transformer $12, total $32.

Maybe I should look into that. Being in Canada though things are just more expensive

 

[Speed of green]

The check valve needs to be there to "stop" the flow, the 1/4in line will draw air after that. On my big 1000 gal tank I used a couple check valves in a row to hold back the pressure. Hope this helps.

 

[OldPhart]

forget check valves, what you need is a simple siphon break, but you need to break the siphon ABOVE the level of the res. From what I can see, all pipe is lower than the res, nothing you can do to stop the water from flowing due to simple gravity. What you need to do is after the pump, run the pipe HIGHER than the level of the res, put a 1/4 drip line from the HIGH point on the pipe, back to the top of the res (not sticking into the water!).. I can promise you that when the pump isn't running, it will NOT pass any water down the pipe. Some times the simple solutions can evade us

 

[queequeg152]

forget check valves, what you need is a simple siphon break, but you need to break the siphon ABOVE the level of the res. From what I can see, all pipe is lower than the res, nothing you can do to stop the water from flowing due to simple gravity. What you need to do is after the pump, run the pipe HIGHER than the level of the res, put a 1/4 drip line from the HIGH point on the pipe, back to the top of the res (not sticking into the water!).. I can promise you that when the pump isn't running, it will NOT pass any water down the pipe. Some times the simple solutions can evade us

problem is a check valve is like 8 bucks, and an air gap, or anti siphon device is going to be like 20 bucks.

also your anti siphon method will result in water passing through this 1/4" tube if placed on the discharge side when the pump is running

it will also result in the pump ingesting air if placed on the suction side as you have essentially just created an air eductor or air venturi...

in the latter case... will the pump still prime? probably, but maby not. water has enormous momentum... assuming the pump can start drawing a slug of water that is iinside the pipe... the air should get up to a high enough velocity to safely pass through the pump... but again maby not.

this is not a centrifugal pump. these do not prime well what so ever... the diaphragms are flexible rubber so they cannot effectively pump a compressible gas, especially when the its pumping this gas against a column of water aka pumping against a positive head.

i would absolutly not run a diaphragm pump with a vacuum breaker like that... feel free to try it out if you like. just observe and listen to the pump. iits possible it would work well enough, but it will make nasty noises when its slugging air mixed into the water, and your emitters should start surging.

just get a spring or poppet check valve. a flapper would work, but only in a vertical orientation... but i DO NOT TRUST cheap small diameter light weight flapper check valves... you cannot service them, and they do not use counter weights to maintain a positive seal, they instead rely on a water column for positive pressure.

flapper check valves are amazing for larger diameter pipes when you are using ductile iron/ flanged iron piping and you have the adjustable counter weight... but since you are nowhere near that size, just use a spring loaded check valve. your pump can handle the pressure losses.

 

[queequeg152]

http://www.homedepot.com/p/Mueller-Global-3-4-in-PVC-Solvent-Weld-Check-Valve-101-604HC/100127314

 

[OldPhart]

I'm going to try one more time since apparently my idea didn't come across properly.

also your anti siphon method will result in water passing through this 1/4" tube if placed on the discharge side when the pump is running

Correct, is this an issue? I would assume the pump could afford to loose a little output, unless it is undersized.

it will also result in the pump ingesting air if placed on the suction side as you have essentially just created an air eductor or air venturi...

What? No, the pump is still at the lowest point, directly connected to the bottom of the res.

in the latter case... will the pump still prime? probably, but maby not. water has enormous momentum... assuming the pump can start drawing a slug of water that is iinside the pipe... the air should get up to a high enough velocity to safely pass through the pump... but again maby not.

this is not a centrifugal pump. these do not prime well what so ever... the diaphragms are flexible rubber so they cannot effectively pump a compressible gas, especially when the its pumping this gas against a column of water aka pumping against a positive head.

i would absolutly not run a diaphragm pump with a vacuum breaker like that... feel free to try it out if you like. just observe and listen to the pump. iits possible it would work well enough, but it will make nasty noises when its slugging air mixed into the water, and your emitters should start surging.

Again, there will be no air in the pump, EVER. Well unless the res runs out of water.

The only air that will be in the system will be in the distribution tubing after the siphon break. It would do like your home sprinkler system when a zone is turned on. It will blow the air out of the tubing, through the drip tubes.

This is all I'm talking about, and will work great if you can handle the air in the distro tubing.

Edit: like the high quality drawing? LOL
I was just looking at the original posting, and noticed that he was having a high head pressure issue. You could put the bypass valve in the place of the drip tube, again, off the high point of the pipe above the res level, then have the bypass tube suspended above the level of the water as a siphon break.
OP

 

[queequeg152]

yea i knew what you were saying. however i wanted to discuss how it would work on the suction side in addition to the discharge side.

placing it on the discharge side would not pose an issue with priming, but again you are allowing the drippers and distribution piping to drain completely becasue you are breaking the vacuum.

if you put a check valve on the suction, its like placing your finger on the end of a straw and lifting it out of the water.

because his emitters are ABOVE the distribution piping(albeit only slightly), they impose a positive head(albeit a small head), and with a vacuum held, will not continue to drain the volume of the distribution piping provided the check valve makes a positive seal.

also again, introducing air into the system after each irrigation cycle will cause surging and splattering each and every time the system primes. it would probably not be a big deal, but having personally seen the surging when i bring my system on line for the first time... i dont think im being conservative when i say its not a good idea to allow this to go on each and every single time it is pumping.

the surging causes misting, and the distribution piping and and micro tubing jump all over the place. again its probably not going to cause any leaks or anything, but it is not ideal.

imho... OP should just switch to regulated emitters w/ a full blast pressure regulated system with a hydraulic accumulator and solenoid. these irrigation systems just run so much better with an accumulator, and the accumulator lends you a great deal more flexability in the emitter sizing and overall sizing of your irrigation zones.

 

[OldPhart]

imho... OP should just switch to regulated emitters w/ a full blast pressure regulated system with a hydraulic accumulator and solenoid. these irrigation systems just run so much better with an accumulator, and the accumulator lends you a great deal more flexability in the emitter sizing and overall sizing of your irrigation zones.

Agreed, a system of that size, you may as well just do it right. I'm a cheap bastard, but I would probably spring for check valve, pressure switch, tank, solenoid valve, and some kind of timer/power supply to activate the valve. I've never messed with that size of a drip system that wasn't outside and buried; which kind of mitigates the surging/misting issues.

 

[Anothermeduser]

also again, introducing air into the system after each irrigation cycle will cause surging and splattering each and every time the system primes. it would probably not be a big deal, but having personally seen the surging when i bring my system on line for the first time... i dont think im being conservative when i say its not a good idea to allow this to go on each and every single time it is pumping.

the surging causes misting, and the distribution piping and and micro tubing jump all over the place. again its probably not going to cause any leaks or anything, but it is

Ive ran like that, completly draining each time and blowing the air out on startup, no problems over long term myself

 

[sheik_yerbouti]

Thanks for all the replies.

I put the check valve back in and sure enough the constant drip stopped. Its beyond me why it doesn't work with my first setup but I'm just happy its working now, so big thanks to Speed for that one.

Queeg....are you suggesting taking out the 1/4" line that returns into the rez? Use the check valve to stop the siphon to keep a vaccum in lines to stop sputtering? I do notice I get better even flow to all the lines right away when there isn't air in the lines. Otherwize it takes a while to get even pressure and even distribution to all the emitters.

And ya I'm sure it would be better to have an accumulator tank but as you can tell I'm having enough trouble with the basics so adding a more complex system is a bit much for me right now. Maybe in the future as I learn about irrigation and the physics of these systems. Head pressure and all that stuff is a foreign language to me.

 

[queequeg152]

Thanks for all the replies.

I put the check valve back in and sure enough the constant drip stopped. Its beyond me why it doesn't work with my first setup but I'm just happy its working now, so big thanks to Speed for that one.

Queeg....are you suggesting taking out the 1/4" line that returns into the rez? Use the check valve to stop the siphon to keep a vaccum in lines to stop sputtering? I do notice I get better even flow to all the lines right away when there isn't air in the lines. Otherwize it takes a while to get even pressure and even distribution to all the emitters.

And ya I'm sure it would be better to have an accumulator tank but as you can tell I'm having enough trouble with the basics so adding a more complex system is a bit much for me right now. Maybe in the future as I learn about irrigation and the physics of these systems. Head pressure and all that stuff is a foreign language to me.

yes that is precisely what i am proposing. however... if you already have the line in place, and its working, you might as well just leave it.

as oldphart said, not much will flow through this tiny line... it will just let air in is all, and hence your distribution side will loose the vacuum and drain out.

if you dont mind the sputtering than just leave the line in place.

regarding the accumulator + solenoid setup... idk man i think im just bad at explaining this shit because i PROMISE you that its not hard what so ever... its super super simple, i think when ever i try to explain this shit i just make it sound harder than it really is... maby someone else can try.

 

[sheik_yerbouti]

yes that is precisely what i am proposing. however... if you already have the line in place, and its working, you might as well just leave it.

as oldphart said, not much will flow through this tiny line... it will just let air in is all, and hence your distribution side will loose the vacuum and drain out.

if you dont mind the sputtering than just leave the line in place.

regarding the accumulator + solenoid setup... idk man i think im just bad at explaining this shit because i PROMISE you that its not hard what so ever... its super super simple, i think when ever i try to explain this shit i just make it sound harder than it really is... maby someone else can try.

Ya I have a feeling that it's more daunting in thought than reality. Another problem for me though is I am seriously lacking in space so fitting a proper sized tank in would be challenging. I have another room that's even bigger that I'll be setting up next so having 2 tanks plus pumps and pressure switches would fill up my little space quickly. That or have to set up a dual solenoid system that let me run 2 rooms off one pump and accumulater with 2 separate reservoirs. It's possible as I have thought about it a lot to save the money on pumps but I just really like the KISS method and having 4 solenoids working to open lines to each room plus accumulator tanks and pressure switches is just getting to be a little much.

This system seems to be working pretty good now, I might add some pressure compensating drippers to each line to get more even flow to each plant, once that's dialed I think it will be about as simple and good as it gets for me.