How to increase psi in my gravity irrigation system?

[goeduck]

I have a gravity system on one of my properties and I would die to have 35 psi, I think mine is about 20 psi. If I were you I would stay with the simplicity of a straight gravity system and get lower pressure rated sprinkler heads.

 

[dougtrr2]

Could you just build a small water tower near the collection box. Then use a windmill or solar powered pump to fill the water tower and gain the needed PSI? I was curious since I didn't notice any mention of timing. Is it continuous irrigation or is there some timing to it?

Doug in SW IA

 

[goeduck]

What kind of irrigation system do you have? 35 psi is not a bad pressure. On another of my properties I have an artesian well with about 10 psi but tons of volume. I do not run spinklers on that one (mostly for livestock water tanks) but gravity and artisan water both make for less hassle.

I believe in Keep It Simple.

 

[RedNeckRacin]

Pretty simple to plumb a pump in and run it when needed. Sure you have to run electric but it works. It will also not be limited by storage volume. I don't know about you guys but I want something that flat out works. I don't want to make things more complicated than needed if I can help it. Have we looked at how expensive it would be to run the electric pump?

 

[goeduck]

Pretty simple to plumb a pump in and run it when needed. Sure you have to run electric but it works. It will also not be limited by storage volume. I don't know about you guys but I want something that flat out works. I don't want to make things more complicated than needed if I can help it. Have we looked at how expensive it would be to run the electric pump?

One of the troubles with adding a pump at the bottom of a gravity system is that you can out pump your flow capacity and cavitate and/or draw air into the pipe. Leaks on a low pressure gravity system can go undetected but if you put suction on the pipe you will draw air in. Also (this happened to me) you may have to worry about the intake getting suddenly plugged (kids playing around or whatever) and the suction shock collapsing the pipe. Adding a pump adds to the suction the pipe full of water already creates. I do not know what pipe the 2-1/2 is made of in this case but mine was not ever expected to be under suction.

 

[plowhog]

Could you just build a small water tower near the collection box. Then use a windmill or solar powered pump to fill the water tower and gain the needed PSI? I was curious since I didn't notice any mention of timing. Is it continuous irrigation or is there some timing to it?

Doug in SW IA

The water box is on a fairly steep slope in a heavily forested area. Probably could not construct a windmill, and the forest canopy blocks solar-- not to mention damage to both from falling limbs and debris.

I use the "Node" irrigation controllers for timed irrigation. I don't have electric wires to any of the sprinklers, but the Node units are battery operated and last a season on a 12V battery.

 

[plowhog]

One of the troubles with adding a pump at the bottom of a gravity system is that you can out pump your flow capacity and cavitate and/or draw air into the pipe. Leaks on a low pressure gravity system can go undetected but if you put suction on the pipe you will draw air in. Also (this happened to me) you may have to worry about the intake getting suddenly plugged (kids playing around or whatever) and the suction shock collapsing the pipe. Adding a pump adds to the suction the pipe full of water already creates. I do not know what pipe the 2-1/2 is made of in this case but mine was not ever expected to be under suction.

This year I added a standpipe in the water box. It is a T off of the 2 1/2 inch PVC supply line. I added this so if there is ever a restriction or plug at the intake I won't collapse the pipe. I used to shut off irrigation water by screwing a cap on the PVC pipe all the way at the top. I got very nervous about that after reading what could happen. I am guessing there used to be a stand pipe but over the years maybe someone took it out. And while there is an air relief valve down the pipe a ways, it is brass and over 50 years old. So I don't want to rely on that.