Large Scale Central

Gravity Drip System

OK today’s wandering thought of the day. So with the construction of the layout one of my goals is to make it green. Why do you ask? Because I am a tinkerer and can’t just do things simple. Saving the environment is only a secondary benefit. I plan to power the layout in 12v DC eventually with all solar but likely with a transformer for awhile. The goal is to be 100% solar out there.

I have the idea to use a gravity fed drip system from a 55 gallon barrel made to look like a water tank that catches rain water from my roof and can be supplemented with domestic water from the tap. After doing some reading unless you can effectively reach around 15 PSI, drip systems can be erratic in their delivery.

In the water world this can be done a couple ways. I am thinking the best way might be the way and RV water system works. Where by a 12v pressure pump is inserted into the system and pressurizes the system and shuts of until the need to pressurize again. Now they pressurize the main holding tank (I think) but I am thinking a check valve on the supply line should be added since it is an open system and then use a pressure tank or bladder to hold the minimum 15 psi. With a reasonable watering regimen I wouldn’t think the pressure pump would need to be used much.

Anyone ever do Scythian like this or have any experience with drip systems and can tell me the demand of these systems. I plan to only have limited vegetation.

Could the system pressure of the domestic water line be used to pressurize the gravity system without itself then supplying all the water? Thus bypassing the need for a pressure pump.

Devon, how are you going to add water to a pressurized tank? The way we did it with ink supply systems, that indecently ran at about 15 psi, was to use a small gear pump driven by an air motor. I would think that a 12 volt DC motor could do the job, if it were big (strong) enough. But, you know about water and pressures and stuff, how high would the barrel need to be above the ground to have 15 PSI at ground level? In other words, what if the barrel were mounted on a platform of some sort? I know the pressure would go down with the water level in the barrel, but, in the dry season you were going to supplement the barrel with tap water anyway.

David, with an Edna lifting injector . . . this from a railroad guy, geez. No that is a good point isn’t it. The barrel would need to be 35 feet high to get 15psi. They do it all the time un-pressurized but results on the drip system are not uniform and require fussing with it to make everything work right.

However lets back up a second, an electric RV pump should, with the installation of a check valve, draw water from the barrel and on its inlet side and then pressurize the system. The checkvalve allows the pressure side to stay pressurized and the open side open. When the pressure drops it activates a pressure switch and charges the system again. This is an everday thing for people on ground water wells.

A pressure tank makes the system “bigger” and therefore sustains pressure longer. the larger the tank the longer the pressure lasts. I am thinking that a sprinkler timer could be used to control the pump (or any electrical timer) so that the system will not maintain pressure all the time but only when needed for watering.

Here’s a thread on standing head (elevation of your tank) vs. pressure.

http://cr4.globalspec.com/thread/22317

Easy to calculate:

2.307 feet of head per psi.

15 psi x 2.307 = 34.61 feet

Devon,

Boats and RVs have “demand” pumps, which strive to keep pressure up in the downstream water delivery system. The water tank is open to the atmosphere.

http://www.starmarinedepot.com/shurflo-pump-aqua-king-ii-standard-3.0-12v.html?gclid=Cj0KEQjwjIy5BRClh8m_9Zu64d8BEiQAtZsQf5jDiDs8BSJV9jaytdL5IpSqKaTaRcUrFRLjpw5bwJ4aAi4O8P8HAQ

On my boat the water delivery is slowly pulsed when a tap is open, as the pump detects the pressure drop and runs until it is back up to snuff.

And yes, they are 12V pumps, and boats often have solar panels. I have 2x 3W-12V panels for my boat to charge the batteries when I am not using it. I’d use a battery (sealed 12V mini) and let the solar charge it all the time.

(I probably have a dead one somewhere around that you could rebuild.)

35 feet high? Sounds like a water tower build project to me.

Devon, do the local laws allow you to collect the rain water off your roof? Before you laugh, that’s not as ridiculous as it sounds.

Pete Thornton said:

Devon,

Boats and RVs have “demand” pumps, which strive to keep pressure up in the downstream water delivery system. The water tank is open to the atmosphere.

http://www.starmarinedepot.com/shurflo-pump-aqua-king-ii-standard-3.0-12v.html?gclid=Cj0KEQjwjIy5BRClh8m_9Zu64d8BEiQAtZsQf5jDiDs8BSJV9jaytdL5IpSqKaTaRcUrFRLjpw5bwJ4aAi4O8P8HAQ

On my boat the water delivery is slowly pulsed when a tap is open, as the pump detects the pressure drop and runs until it is back up to snuff.

And yes, they are 12V pumps, and boats often have solar panels. I have 2x 3W-12V panels for my boat to charge the batteries when I am not using it. I’d use a battery (sealed 12V mini) and let the solar charge it all the time.

(I probably have a dead one somewhere around that you could rebuild.)

So RV and boat tanks are also open. So What I want to do is exactly what an RV system does. Only by adding a substantial bladder or pressure tank and the minimal demand of the drip system pressure should be sustained for awhile.

Steve Featherkile said:

Devon, do the local laws allow you to collect the rain water off your roof? Before you laugh, that’s not as ridiculous as it sounds.

No your right it isn’t ridiculous at all. CA and WA both outlaw it at the state level. Oregon is by county I believe. Other states require a water right permit. Idaho however does not require one. Many states are now considering water to be a public resource regardless of where one finds it. Rain water, springs on your property, streams running through, its all consider to be public property. The reason being is that it is the water cycle that replenishes the streams and aquifers. If we block any part of the cycle then we effect the entire cycle.

However, I have a major argument to the thinking. If I capture water from my roof and then apply it to my land as irrigation then that water will still end up either evaporating or replenishing the aquifer. I haven’t blocked anything. Its a broad action law to prevent private companies from removing water from the cycle.

Todd Brody said:

Easy to calculate:

2.307 feet of head per psi.

15 psi x 2.307 = 34.61 feet

Another way to say the same thing is ever .433 feet of elevation yields 1 psi. 15/.433=34.64 feet. Were off a few but they both work.

So, 55 gallon drum at 33 or 34 feet off the ground, with some sheet metal work to make it look like a proper water tower, with Post Falls painted on the side. If you put it where it can be seen from the street, you could have a landmark that folks would be talking about.

David,

Your sorta missing a key element of this project. Its a rain water collection barrel collecting run off from my roof. I am almost positive there will be an issue with me putting up a water tank 35 feet in the air; I might need a permit. But I am almost certain they won’t issue me a permit for raising my house 35 feet into the air.

That’s because you don’t live in Seal Beach. This is called “killing two birds with one stone.” (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

BTW, the structure originally served steam engines.

http://www.odditycentral.com/pics/california-water-tower-is-actually-a-beautiful-3-storey-house.html

Devon, I didn’t miss the point, I was making a joke.

I know David and that was my missed attempt to make one back

Todd,

Talk about having a house fit the theme

I dunno Devon. A house 35 feet up in the air would have certain advantages. And, certain disadvantages. If you were to put your house up that high, you would not have to worry about flooding, you would have a large covered space to park your project car, and giving directions to your house would be easy. But the stairs would be a killer. 3 flights of stairs and I am in need of a pause, to let my knee quit complaining and catch my breath. I couldn’t see doing that every time I wanted to go inside.

I took and drilled holes in the drip pipes every 1/2". seven 55 gal. barrels and a timer water my raised beds quite well.

Dave M.