Personally I just use the Protein weight gain,but there's a guy at my Gym that sells em on the DL. 
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How do solenoids work?
- Thread starter Student Of Life
- Start date
I would just use a leader pump
https://www.amazon.com/Leader-Ecotr...der+pump&qid=1566953910&s=gateway&sr=8-2&th=1
That pump is designed to automatically turn on when it senses a valve opens...no timer needed. That way you only have to control the low voltage solenoid valves.
https://www.amazon.com/Leader-Ecotr...der+pump&qid=1566953910&s=gateway&sr=8-2&th=1
That pump is designed to automatically turn on when it senses a valve opens...no timer needed. That way you only have to control the low voltage solenoid valves.
Student Of Life
Member
Thanks man! Perfectly clear. Are flap check valves needed with solenoids, or does their design inherently prevent them? My siphoning issue wasn't water flowing back into the res, it was the 'chain' or vaccum of liquid from the res to the dripper lines being unbroken, or broken slowly, so they'd get fed way more than they should have after the pump turned off.
Any recommendations for solenoid brands? Have you ever have any of them fail on you? I'm gonna install a ball valve just behind each solenoid so I can manually shut off water to each feed line in case the solenoids malfunction.
Would you recommend pressure regulators? The 10+ GPM figure you quoted is accurate. I've got a .5 hp pump rated at ~1500 GPH, comes out to 25 GPM. That pressure won't be divided between liens either, as each 4x8 will have it's own solenoid and feed line. I'm concerned about having too much pressure tbh. The pressure, the siphoning, and the wiring are my concerns atm. I think I have the general concept down though.
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CrushnYuba
Well-known member
don't think a check would be needed for that. The valve would close. Siphoning won't be an issue as long as the valve doesn't fail.
I don't have any brand recommendations. They all kind of work the same. They can fail from being clogged. Doesn't happen alot. Orbits are really cheap and available at hardware stores. You don't need a ball valve on every line. Just one manual master valve and some spare parts. They are super easy to take apart, clean and fix.
You may need a pressure regulator. It really Depends on the irrigation setup. I really doubt there is any .5 hp pump capable of putting out 25gpm at any decent pressure and i would be doubtful of any pump rated that optimistically. What kind of pump is it? I usually see .5 hp single stage jet pumps putting out a little over 10gpm. I could make a pump recommendation if you don't have one already. Sizing a pump correctly is important.
I don't have any brand recommendations. They all kind of work the same. They can fail from being clogged. Doesn't happen alot. Orbits are really cheap and available at hardware stores. You don't need a ball valve on every line. Just one manual master valve and some spare parts. They are super easy to take apart, clean and fix.
You may need a pressure regulator. It really Depends on the irrigation setup. I really doubt there is any .5 hp pump capable of putting out 25gpm at any decent pressure and i would be doubtful of any pump rated that optimistically. What kind of pump is it? I usually see .5 hp single stage jet pumps putting out a little over 10gpm. I could make a pump recommendation if you don't have one already. Sizing a pump correctly is important.
Student Of Life
Member
It's a 'mondi gold series 1585', claims 1585 GPH, which /60 = 25. So does it go
1" line from res --> 1" disc filter --> 3/4" solenoids --> 3/4" 35 psi pressure regulator --> 3/4" poly tubing --> PC emitters --> 1/4" tubing --> plants' pot. The emitters are 7GPH, and there will be between 8 and 20 emitters per table, and only one table will be running at any given time. So I'd need a pump capable of putting out 50-150 GPH. In the future I could have multiple tables be the same strain, so perhaps up to 300-500 GPH would be nice. Is there overkill on the pump's strength? Can they overpower pressure regulators or disastrously crack/destroy the PVC mainline somehow?
Edit - The line from the res to the first table is 14 feet, to the last table is ~35ft. Line only goes up as high as it needs to in order to get out of the res, which is a 55gal blue drum.
Edit2 - Forgot to add the disc filter to the order of things.
1" line from res --> 1" disc filter --> 3/4" solenoids --> 3/4" 35 psi pressure regulator --> 3/4" poly tubing --> PC emitters --> 1/4" tubing --> plants' pot. The emitters are 7GPH, and there will be between 8 and 20 emitters per table, and only one table will be running at any given time. So I'd need a pump capable of putting out 50-150 GPH. In the future I could have multiple tables be the same strain, so perhaps up to 300-500 GPH would be nice. Is there overkill on the pump's strength? Can they overpower pressure regulators or disastrously crack/destroy the PVC mainline somehow?
Edit - The line from the res to the first table is 14 feet, to the last table is ~35ft. Line only goes up as high as it needs to in order to get out of the res, which is a 55gal blue drum.
Edit2 - Forgot to add the disc filter to the order of things.
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Damn SOL you are complicating your system here as the pressure regulator will not be needed if you are using that mondi pump as it will not produce near 35 PSI.
Just a guess but I am thinking that you are copying someones irrigation system that runs off city water or a high pressure pump and that isn't what you have.
The emitters that you plan on using should be pressure compensating VS simple orifice because of the difference in length of hose run if you want the emitters to all flow equal.
Just a guess but I am thinking that you are copying someones irrigation system that runs off city water or a high pressure pump and that isn't what you have.
The emitters that you plan on using should be pressure compensating VS simple orifice because of the difference in length of hose run if you want the emitters to all flow equal.
Student Of Life
Member
I mean shoot, I hope I don't need the regulators, would save me a couple of dollars lol. Considered it, but I don't know how GPH/GPM translates into PSI, so figured I'd play it safe and not blow the emitters off of my lines. The emitters are pressure-compensating, that's why I called them "PC emitters", but the pressure compensation fails if you go above a certain PSI, which I think is generally 40 or 50, depending on the company.
I imagine the PC emitters need at least a bar each. So you need a pump that can deliver 150gph while maintaining a Bar of pressure. Unfortunately your pump can't supply any water at a Bar.
A bar is a 10 meter head. Your pump runs out of guts at a 9 meter lift. It's a great circulation pump, but has no use in a high pressure system.
7gph emitters are huge you know. You talk of 100ml doses. That's a 13 second interval. An emitter of about 0.5gph produces a stream of water, not drips. At 7gph you are looking at erosion and compaction issue, with no soak time. People are thinking 10 mins run time, for a good soak, that reaches a critical volume then drops out as if breaking water tension. Are these emitters spray heads? Because with fertigation that is a big can of worms.
These 4x8 tables, is that meters, and is it pots or beds. How many plants sites.
A bar is a 10 meter head. Your pump runs out of guts at a 9 meter lift. It's a great circulation pump, but has no use in a high pressure system.
7gph emitters are huge you know. You talk of 100ml doses. That's a 13 second interval. An emitter of about 0.5gph produces a stream of water, not drips. At 7gph you are looking at erosion and compaction issue, with no soak time. People are thinking 10 mins run time, for a good soak, that reaches a critical volume then drops out as if breaking water tension. Are these emitters spray heads? Because with fertigation that is a big can of worms.
These 4x8 tables, is that meters, and is it pots or beds. How many plants sites.
CrushnYuba
Well-known member
No way you will need a pressure regulator. That pump is just like a sump pump. It's super low pressure ( lift). It may produce good flow with no restriction just open flow at the top of the pump with no pipe attached at a low pressure, but it doesn't produce the pressure to overcome the pipe and tubing attached.
I don't think it would even work with a pressure regulator. U may not even have enough pressure to open and close the solenoid valves. It doesn't produce enough pressure to work with a pressure switch either. It night not even be enough pressure to push through the pc emitters.
That type of pump is terribly inefficient for irrigation. I personally don't use them. A 1/2 hp motor in the right pump can do allot. A 1/2 hp, multi stage submersible well pump can pump water 200ft up a well through 1" pipe and still be at 45 psi and 10gpm at the top to feed a house or irrigation system.
For your situation, i would recommend a small diaphragm delivery pump. Something designed to produce the flow and pressure you need efficiently. It will come with a built in pressure switch so the pump will work automatically when a valve opens. You won't have to wire it to the irrigation controller. It will only cost about 60$ and it will use wayy less power then that pump you planned on using. Flowjet and shurflo both make pumps like this.
I don't think it would even work with a pressure regulator. U may not even have enough pressure to open and close the solenoid valves. It doesn't produce enough pressure to work with a pressure switch either. It night not even be enough pressure to push through the pc emitters.
That type of pump is terribly inefficient for irrigation. I personally don't use them. A 1/2 hp motor in the right pump can do allot. A 1/2 hp, multi stage submersible well pump can pump water 200ft up a well through 1" pipe and still be at 45 psi and 10gpm at the top to feed a house or irrigation system.
For your situation, i would recommend a small diaphragm delivery pump. Something designed to produce the flow and pressure you need efficiently. It will come with a built in pressure switch so the pump will work automatically when a valve opens. You won't have to wire it to the irrigation controller. It will only cost about 60$ and it will use wayy less power then that pump you planned on using. Flowjet and shurflo both make pumps like this.
Many PC emitters are self cleaning. This means that when you switch off, lowering pressure, they are wide open. Emptying your lines, and any crud that had got in the valve has a larger hole to escape through. They actually need the pressure (a bar usually) to clamp down to the rated flow.
This can cause problems with weak pumps. If the 7gph emitter is wide open at perhaps 14gph, then the 150 pump, would need to be a 300. This pump in question couldn't even close one emitter, so if they are self cleaning, that 13 second watering interval could be halved.
I'm not keen on positive displacement pumps. Some $20 shurflo's are 80&90psi. Using just 1/10th of a horse. It's too high for push on pipe connections. Domestic mains water is often half of that.
I'm hearing 20 pots. So thinking 60 arrow drippers. Each table with it's own $30 RV pump. Anti-syphon taken care of with sprung check-valves. An RV pump can power a shower and a couple of taps (well some can) and they are a nice safe 12/24v. Pressure at each emitter can be evened out by proper pumping(equal pressure manifold). Arrows are happy with rubbish pumps, but are aimed at a bar. You can put about 100 on a reasonable RV pump, and each will emit 40ml a minute. 120ml per plant site. A typical duration for a plug in timer.
Anyone can work that
This can cause problems with weak pumps. If the 7gph emitter is wide open at perhaps 14gph, then the 150 pump, would need to be a 300. This pump in question couldn't even close one emitter, so if they are self cleaning, that 13 second watering interval could be halved.
I'm not keen on positive displacement pumps. Some $20 shurflo's are 80&90psi. Using just 1/10th of a horse. It's too high for push on pipe connections. Domestic mains water is often half of that.
I'm hearing 20 pots. So thinking 60 arrow drippers. Each table with it's own $30 RV pump. Anti-syphon taken care of with sprung check-valves. An RV pump can power a shower and a couple of taps (well some can) and they are a nice safe 12/24v. Pressure at each emitter can be evened out by proper pumping(equal pressure manifold). Arrows are happy with rubbish pumps, but are aimed at a bar. You can put about 100 on a reasonable RV pump, and each will emit 40ml a minute. 120ml per plant site. A typical duration for a plug in timer.
Anyone can work that
CrushnYuba
Well-known member
F-E: we are talking about the same kind of pump. The kind of shurflo i am talking about are made to be used in RV's usually. I have never seen an rv pump that wasn't a positive displacement diaphragm pump. Shurflo is the largest manufacturer of RV pumps.
Shurflo also makes higher pressure lower volume diaphram pumps for stuff like spraying. That's the pump you aren't to keen on.
RV pumps have built in pressure switches. So when you open a tap or solenoid valve, pressure drops and it turns on automatically. You don't have to use multiple pumps and timers. One controller, One pump, and a few valves are all that's needed.
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CrushnYuba
Well-known member
You also have to realize when a pump is rated at a psi of pressure and a gpm of flow, they make it somewhat deceiving.
Like some shurflos say 45psi and 3.5gpm. They don't make it clear that it's 45psi OR 3.5gpm. When it is flowing at an open flow of 3.5gpm it is not at 45psi. It's probably more like 25psi. It doesn't hit 45 psi until the flow gets restricted. When the valve closes, the pump will keep pumping until pressure hits 45 psi and the switch tells it to turn off. It doesn't actually ever go through the irrigation system at 45psi even. It is only 45 psi up to the valve when it is closed.
Like some shurflos say 45psi and 3.5gpm. They don't make it clear that it's 45psi OR 3.5gpm. When it is flowing at an open flow of 3.5gpm it is not at 45psi. It's probably more like 25psi. It doesn't hit 45 psi until the flow gets restricted. When the valve closes, the pump will keep pumping until pressure hits 45 psi and the switch tells it to turn off. It doesn't actually ever go through the irrigation system at 45psi even. It is only 45 psi up to the valve when it is closed.
Student Of Life
Member
Crushn, do you mean a pump like this?
https://www.amazon.com/SHURflo-2088...sr_1_9?keywords=shurflo&qid=1581372052&sr=8-9
And I'm looking for a 6-zone irrigation controller than can control down to the second, but most seem to only work by the minute. Considered getting the Aqua-X so that I can expand the system in the future into multiple rooms, and the water sensor feature is nice, but also considering going with a cheaper controller for the time being, since I don't have multiple rooms up atm.
https://www.amazon.com/SHURflo-2088...sr_1_9?keywords=shurflo&qid=1581372052&sr=8-9
And I'm looking for a 6-zone irrigation controller than can control down to the second, but most seem to only work by the minute. Considered getting the Aqua-X so that I can expand the system in the future into multiple rooms, and the water sensor feature is nice, but also considering going with a cheaper controller for the time being, since I don't have multiple rooms up atm.
Student Of Life
Member
And to clarify some confusion about plant/site counts. There'll be anywhere between 6 and 15 plants per table (4x8ft), with 1 to 2 sites per plant, so 6-30 sites. 30 sites is to make room for future expansion, it's not currently relevant as I'm currently running 10 plants per table. I do 1-2 gallons coco. Have never found a necessity in the past of having more than one emitter per pot, regardless of GPH rating, but since I do alot of pheno hunting, sometimes one of the girls gets a growth spurt and becomes very thirsty, so I add another line to her pot with a smaller emitter to give her some extra love, hence me leaving room in the equation for 2 emitters per plant. I always like to calculate things a little oversized.
Decided to stick with 2GPH emitters since it's whats available atm, I've got a hundred or so of them laying around. So 6-30 sites at 2GPH = between 0.2 and 1 GPM rating. The emitters are rainbird, which are rated for 10-50 psi. I'd like that to be around 20-30 to be in the safe zone. I was considering this pump right here (which you can find for much cheaper on amazon etc)
https://www.leaderpumpshop.com/Products/Irrigation/EcoJet/ECOJET-R-90.aspx
but my rated needs, calculated from this video;
https://www.youtube.com/watch?v=jgrHRPdcFeQ
comes out to 1 GPM and ~80ft head. So the linked pump is 5x stronger than my needs, rated at 5GPM at 80ft head. This is why I asked about pressure regulators. The pumps youre mentioning are cheaper and weaker, which sounds convenient. I don't know about design differences (centrifugal vs diaphragm), that's above me.
The pump only being on when a pressure difference occurs confuses me a bit. When the solenoids open and the pump kicks on, does it ever turn off mid-watering cycle if it momentarily reaches desired PSI? If so, it would cycle on/off quickly. Is that a concern/does that happen? Most of these pumps seem to be available only as wired units, as in there's no plug on them. Would I just wire them to an irrigation controller and have them "on" 24/7?
Decided to stick with 2GPH emitters since it's whats available atm, I've got a hundred or so of them laying around. So 6-30 sites at 2GPH = between 0.2 and 1 GPM rating. The emitters are rainbird, which are rated for 10-50 psi. I'd like that to be around 20-30 to be in the safe zone. I was considering this pump right here (which you can find for much cheaper on amazon etc)
https://www.leaderpumpshop.com/Products/Irrigation/EcoJet/ECOJET-R-90.aspx
but my rated needs, calculated from this video;
https://www.youtube.com/watch?v=jgrHRPdcFeQ
comes out to 1 GPM and ~80ft head. So the linked pump is 5x stronger than my needs, rated at 5GPM at 80ft head. This is why I asked about pressure regulators. The pumps youre mentioning are cheaper and weaker, which sounds convenient. I don't know about design differences (centrifugal vs diaphragm), that's above me.
The pump only being on when a pressure difference occurs confuses me a bit. When the solenoids open and the pump kicks on, does it ever turn off mid-watering cycle if it momentarily reaches desired PSI? If so, it would cycle on/off quickly. Is that a concern/does that happen? Most of these pumps seem to be available only as wired units, as in there's no plug on them. Would I just wire them to an irrigation controller and have them "on" 24/7?
PurplePotion
Member
They make accumulators to stop the cycling issue you’re referring to. Just plumb it in-line after the pump and set it 2-3psi less than when the pump kicks in (typically 15psi less than it’s rated output pressure; ie: a 60psi pump kicks on at 45psi and kicks off at 60, so you set the accumulator to 42-43psi. All done with a standard tire gauge and air compressor.)
CrushnYuba
Well-known member
Yes. Like that shurflo, but that one seems a little expensive for a 3.5gpm unit. I think mine were more like 45$ for 3.5 gpm. They also make smaller rv pumps if you really aren't going to go over 1gpm. Diaphragm pumps cycling isn't a huge deal.
You would just wire the pump to a power source always on. Not to the irrigation controller at all.
I think that leader pump is garbage. It is made to run off no pressure tank (acumulator). It's way oversized for your situation. If you did expand and get into bigger stuff, there are way better options for larger pumps. I have a few off these pumps that i really like and they are cheap.
https://www.amazon.com/Bur-Cam-5062...ywords=jet+pump+package&qid=1581384166&sr=8-3
That one is 3/4hp but you can get packages like that with smaller motors on the pump.
I run them basically at full flow. My zones are like 14gpm. But because it has a 5 gal accumulator it could do 1gpm without getting pump chatter. It would cycle but not rapidly. You can put a cycle stop valve on it, and it wouldnt cycle at all. The CSV valve and a small pressure tank around 5 gallons are what they are using in houses these days instead of big 30 gallon pressure tanks. CSV valves with small tanks are also replacing expensive variable frequency drive pumps.
You would just wire the pump to a power source always on. Not to the irrigation controller at all.
I think that leader pump is garbage. It is made to run off no pressure tank (acumulator). It's way oversized for your situation. If you did expand and get into bigger stuff, there are way better options for larger pumps. I have a few off these pumps that i really like and they are cheap.
https://www.amazon.com/Bur-Cam-5062...ywords=jet+pump+package&qid=1581384166&sr=8-3
That one is 3/4hp but you can get packages like that with smaller motors on the pump.
I run them basically at full flow. My zones are like 14gpm. But because it has a 5 gal accumulator it could do 1gpm without getting pump chatter. It would cycle but not rapidly. You can put a cycle stop valve on it, and it wouldnt cycle at all. The CSV valve and a small pressure tank around 5 gallons are what they are using in houses these days instead of big 30 gallon pressure tanks. CSV valves with small tanks are also replacing expensive variable frequency drive pumps.
It's quite a linear line when graphed out. From 3.5gpm if there is absolutely no resistance to flow, to 45psi being made when the water flow is about static.
The Whale GP1692 delivers 1.5gpm@1bar and has a maximum pressure of 1.5bar, so can just be run, even using just one dripper. It has the capacity to water two tables, and as an inline design, you can use them in a row to double the pressure.
This idea of using them inline, has me looking on amazon at 'Pump 800L/H 5M' for $10. Two in a row is 15psi and with less than a third of the capacity being taken, they look great. However, the published power consumption don't add up and they talk of PC cooling. Money back though surely?
1 second duration timers are a little rare.
https://www.internetreptile.com/lucky-reptile-pro-digital-timer-et-2uk/
Problem here, is that won't switch a 12v 5amp psu, any more reliably than it would a 600w HID.
I instead use a 12v system for the timers, and in turn use power relays or 30a automotive relays for the pump. I'm not sure of your skill set, but this is the part of interest TM-618sh which is not wired up the way the manufacturer believes. Not on any of their timers. If you use the 230v version, to switch 12v as they should, it joins the 230v neutral to the 12v live. Each design has a different problem, but I'm here to help.
The Jebao dosing units offer a timer with up to 8 items being controlled. It only has an on time, then a run time in ml though.
For emitters you should really be ok with a timer to the nearest minute. You aim for about 10 minutes anyway. But if you're thinking about 12v then the timer needs to be good for a 600, Or use further switchgear as you would for a 600.
Sureflo is indeed a misting/water injection pump to me, and I had just been on another project and had a brain jam. They make lots and lots of pumps. Many aimed at bilge will be happy with our salty water.
I control siphoning with these https://duckduckgo.com/?q=double+ch...gz.co.uk/width=1000/height=1500/imgf93403.jpg
It's a non return valve, that has a small spring to close the valve, not just a loose ball or flap. It is actually two such valves in a row. It's a double check valve. For water to flow in the right direction, it must first overcome the spring tension. A tank a meter higher than your drippers doesn't have the head to overcome the spring. I actually smash one of the two valves out when using a typical setup. You simply can't blow through it, unless you take one out. Then it's still difficult.
This completes my line-up. The 12v psu. 12v timer. Power relay. RV pump. Check valve.
Slip a filter in just after the pump, so you can open it (or get a leak) and any drips don't go on the floor. You must also open it, with the pump submerged, to allow air out the pump and water to get in. If you use these pumps dry they fail. They must be primed and not run till they pull air.
These pumps may only last a couple of years at 15 minutes a day. I have not had one fail except for developing a rattle from dry running, but some brands talk of 150 hours, like the Rule IL series. Maybe 15 years I have used the Whale brand and surely had 500 hours before people have run them dry. Though two pumps in-line offers a great safety margin, I have never bothered. But these submersible pumps are a lot cheaper in smaller sizes from China.
Note these are 60w pumps. If kept away from the edge of the barrel, you can't hear them running, even with all your fans off. I have mechanical timers that tick louder. Keeping them off the bottom by 8" is easy enough with an inline, as a silicone tube can reach from the pump to the bottom. I have seen commercial grow shows where the pumps have been bricked in they were so loud.
I'm interested to see what parts other people put forward. I notice the BURCAM 506227P 3/4 HP linked to above is under a Bar so falls in the low pressure drip system category.
CrushnYuba
Well-known member
I don't know off you could run 2 off those pumps in line. Maybe you could. It seems like it's kind of making things complicated. I have no idea what that pump is. It doesn't seem to be meant to be used as a stand alone pump for a small water system like an RV.
I do pump service for a living. Mostly installing deep well pumps and booster pumps for pumping out of storage. I also do irrigation. I install everything properly and do everything to code. It's all for homes, landscaping and commercial gardens. A properly installed well pump has to run for 10 years. I don't make up my own way of doing things or rig stuff. I do it the way any other professional pump service would do it. I do my irrigation the way any other professional service would do it. It's not theory or my own creation. It's tried and true standard way of doing it. None of this stuff really needs to be reinvented.
Its probably easier to think of this as if you were doing a water system for a house.
That burcam i posted is not low pressure. It's a jet pump. It comes with the pressure switch set at 30/50 but it can be adjusted. It keeps pressure between 30 and 50psi. That's between 2 and 3.5 bar ( standard household water pressure). Jet pumps are pretty much the standard way of pumping out of a shallow wells or water storage at household pressure and flow. Its at that pressure if you are just cracking a faucet or you are running sprinklers at 15gpm.
If you need to pump out of a deep well or up a steep hill our any other reason that you need to overcome allot of head, it's standard to use a multi stage submersible pump.
Houses on wells or storage almost always use one of these 2 types of pumps. They can use different sized motors and different pumps for different situations. They can be gotten in packages but they always are used with a pressure tank and switch.
In a situation like an RV, boat or tiny home, that you want household pressure but your flow is always low, it's standard to use a diaphragm delivery pump with a built in pressure switch like a shurflow. Diaphragm pumps do well at producing good pressure at low flows. Positive displacement pumps are not linear the way you think. I bet that shurflo would be capable of pumping 1-3gpm at 45psi through a small diameter pipe. It just wouldn't do it at it's flow LIMIT of 3.5gpm.
I do pump service for a living. Mostly installing deep well pumps and booster pumps for pumping out of storage. I also do irrigation. I install everything properly and do everything to code. It's all for homes, landscaping and commercial gardens. A properly installed well pump has to run for 10 years. I don't make up my own way of doing things or rig stuff. I do it the way any other professional pump service would do it. I do my irrigation the way any other professional service would do it. It's not theory or my own creation. It's tried and true standard way of doing it. None of this stuff really needs to be reinvented.
Its probably easier to think of this as if you were doing a water system for a house.
That burcam i posted is not low pressure. It's a jet pump. It comes with the pressure switch set at 30/50 but it can be adjusted. It keeps pressure between 30 and 50psi. That's between 2 and 3.5 bar ( standard household water pressure). Jet pumps are pretty much the standard way of pumping out of a shallow wells or water storage at household pressure and flow. Its at that pressure if you are just cracking a faucet or you are running sprinklers at 15gpm.
If you need to pump out of a deep well or up a steep hill our any other reason that you need to overcome allot of head, it's standard to use a multi stage submersible pump.
Houses on wells or storage almost always use one of these 2 types of pumps. They can use different sized motors and different pumps for different situations. They can be gotten in packages but they always are used with a pressure tank and switch.
In a situation like an RV, boat or tiny home, that you want household pressure but your flow is always low, it's standard to use a diaphragm delivery pump with a built in pressure switch like a shurflow. Diaphragm pumps do well at producing good pressure at low flows. Positive displacement pumps are not linear the way you think. I bet that shurflo would be capable of pumping 1-3gpm at 45psi through a small diameter pipe. It just wouldn't do it at it's flow LIMIT of 3.5gpm.
Student Of Life
Member
Thanks Crushn. You're saying that the leader pump is no good because it has no accumulator, which means it will cycle on/off constantly? As for it (or any other pump) being oversized for my use, does this matter? Say for example a pump is rated at 12 GPM at 30psi, yet I'm using it for only 2GPM worth of emitters at 30 psi. I'm beginning to understand that flow =/= pressure, but I'm wondering where all those extra GPM go, if not translated into excess pressure, if you understand my confusion. Is there a danger in having an oversized pump in terms of flow? The lines I'm running won't have a return to the res, they'll simply cap at the end of the main line, and the end of each feeding line will have a flush valve which is shut when pressure is introduced, so there's no escape for extra pressure/water.
Edit - Another thing I'm still confused about is pipe sizing. Some of these smaller diaphragm pumps have small outlets, like 1/2" or even 1/4". Won't screwing this into a 1" adapter/coupler reduce pressure, since I'm increasing pipe size? I cannot have a 1/2" main line running to 5 different zones, as the solenoids themselves are a minimum size of 3/4", and I'm used to having the main line either be identical in size or larger than the feed lines they split off into.
Edit - Another thing I'm still confused about is pipe sizing. Some of these smaller diaphragm pumps have small outlets, like 1/2" or even 1/4". Won't screwing this into a 1" adapter/coupler reduce pressure, since I'm increasing pipe size? I cannot have a 1/2" main line running to 5 different zones, as the solenoids themselves are a minimum size of 3/4", and I'm used to having the main line either be identical in size or larger than the feed lines they split off into.
CrushnYuba
Well-known member
Yes. I don't like that leader pump because there is no accumulator. It's just a cheap jet pump with a cheap tankless pressure switch screwed onto the top. You can get that pressure switch and ones like it that will go on any jet pump. They just don't work well. Those tankless switches usually cycle the pump too fast AND they operate at a crazy wide range of pressure.
The best way to use a large pump at a low flow in my opinion is with a 5 gal accumulator tank and a cycle stop valve. The csv valve will keep a constant pressure in the lines with any flow without cycling the pump.
A fancy variable frequency drive pump can do the same thing by slowing down the motor. It keeps a constant pressure and doesn't need any tank. but those setups are really really expensive.
Those are the new ways of doing it. The old way is with a large pressure tank. The pump will cycle but slowly. The larger the tank, the slower it will cycle. Most houses i see with these traditional setups have tanks around 30 gallons. Pressure will not be constant, it will cycle in the range of the pressure switch. Like with a 30/50 switch the pump kicks in when pressure drops below 30 and it turns off when it hits 50. But that's wayy better then a tankless controller also.
The reason diaphragm pumps have small inlets and outlets is because they don't flow fast. The friction loss in a 1/2" pipe flowing at only a couple gpm is minimal. You don't have to use a much larger pipe. You can though and it won't hurt anything. The pressure in the pipe won't really be reduced because it still has to push against your emitters too get out of the pipe. The only reason you would really have to use a larger pipe is if its running a very long distance. You could look up a pipe sizing calculator online. You put in the the length of pipe and your flow. It will tell you exactly what your friction loss will be for different pipe diameters... I ran 3,000ft of 1" pipe before that i was running 10gpm through.
Your biggest concern should be if your solenoid valves will function properly at the low flow you are using. Size of valve doesn't have to match size of pipe. It will say on the valve what flow range it can function with. They make low flow and adjustable flow valves.
The best way to use a large pump at a low flow in my opinion is with a 5 gal accumulator tank and a cycle stop valve. The csv valve will keep a constant pressure in the lines with any flow without cycling the pump.
A fancy variable frequency drive pump can do the same thing by slowing down the motor. It keeps a constant pressure and doesn't need any tank. but those setups are really really expensive.
Those are the new ways of doing it. The old way is with a large pressure tank. The pump will cycle but slowly. The larger the tank, the slower it will cycle. Most houses i see with these traditional setups have tanks around 30 gallons. Pressure will not be constant, it will cycle in the range of the pressure switch. Like with a 30/50 switch the pump kicks in when pressure drops below 30 and it turns off when it hits 50. But that's wayy better then a tankless controller also.
The reason diaphragm pumps have small inlets and outlets is because they don't flow fast. The friction loss in a 1/2" pipe flowing at only a couple gpm is minimal. You don't have to use a much larger pipe. You can though and it won't hurt anything. The pressure in the pipe won't really be reduced because it still has to push against your emitters too get out of the pipe. The only reason you would really have to use a larger pipe is if its running a very long distance. You could look up a pipe sizing calculator online. You put in the the length of pipe and your flow. It will tell you exactly what your friction loss will be for different pipe diameters... I ran 3,000ft of 1" pipe before that i was running 10gpm through.
Your biggest concern should be if your solenoid valves will function properly at the low flow you are using. Size of valve doesn't have to match size of pipe. It will say on the valve what flow range it can function with. They make low flow and adjustable flow valves.
