What to do to increase GPM without breaking the bank?

[JudgeDroid]

Hi. I need help. I am in process of installing a sprinkler system at my house. The incoming city water pressure is 60psi. The main line is 3/4" copper but as the house is more than 50 years old, the pipe should have sediment build up. Doing a GPM test with 5 gallon bucket is giving me around 6.5gpm reading. The reading is from the first faucet on a new 3/4" copper line right after the meter. What can I do to improve the GPM to make it around 8-10 GPM at a minimum? Planning to have Hunter pgp ultra heads with 4 in each zone, a total of 10 zones. Thanks

 

[Jadnashua]

Copper doesn't usually end up with a significant buildup. Are you sure that the shutoff valves in the line are fully opened? AN old gate valve may not be fully opened. A full-port ball valve would be the best choice.

 

[Sponsor]

 

[JudgeDroid]

Copper doesn't usually end up with a significant buildup. Are you sure that the shutoff valves in the line are fully opened? AN old gate valve may not be fully opened. A full-port ball valve would be the best choice.

Yes.. The line has ball valves.. Both before and after the meter. The new line for sprinkler is right after the meter which was also replaced couple weeks ago by township.

 

[CountryBumkin]

You should check the gpm at another faucet too. Maybe something is restricting that first faucet (like a kink in the line or some internal buildup (even though line was replaced) - can you see the entire line?).

 

[hj]

why are you testing at the house if the irrigation is connected "Right after the meter"?

 

[JudgeDroid]

why are you testing at the house if the irrigation is connected "Right after the meter"?

A new ball valve faucet was added to the line which will feed the sprinkler system... It's a new copper pipe not more than 10 ft long from the meter. No kinks in it as its a straight run. I am testing from there.. Another issue is as that faucet is opened, there's hardly enough water going to the entire house.

 

[JudgeDroid]

Also, my plumber is suggesting to add a 15gallon tank with a pump.. This is the way he says that we can increase GPM - by sending 80-90psi in the sprinkler line and put a pressure reducer to send 60psi to the entire house. But it's costing 2k for the entire job. And I have to add cost of electrician to run a new circuit as well. This is quite costly and unplanned expense.. So, looking at the forum to suggest any other idea. I also read increasing psi will add stress to the sprinkler lines which is not good in the long run.

 

[Plumber69]

Add a loop in ur plumbing. Will keep things up to gpm when other things our running

 

[Dj2]

1. At 60 psi, your city incoming water pressure is too low. better to have it higher and add a PRV. Can you ask your neighbors about their water pressure? Is your water pressure gauge in good working order?

2. Your main water supply from the meter to the house is only 3/4". Then you branch out for a sprinkler system, causing water pressure inside the house to drop significantly. Better to have a 1" main.

3. You say you have a new meter. Did you have low pressure with the old meter as well? Maybe you need your water company to come and check the new meter, it's a free call. A careless water department technician may let small rocks and dirt enter the meter while changing it, restricting outflow - I've seen it happen.

 

[Terry]

3/4" is too small if you're trying to run more than one head at a time. At the least you want 1"
I have even run 1.5" on large lots where I expect to run five heads at once.
There is a lot of friction loss trying to push much water through a tiny straw.
My mothers line was 3/4" running 250 feet to the house. We then went under the home, and out the other side, and up a hill to the back yard, adding another 200 feet. Changing the line from the meter made all the difference in the world.

 

[Cool Blue Harley]

What size is the new water meter supplied by the city?

A 3/4 inch water service is too small, the minimum allowed by code. The supply pipe size needs to be based on the total demand.

Each type of piping material has limitations on its ability to withstand the erosive effects of water flow at high velocities. If the velocity is too great, damage occurs.

Recommend a larger service up to your irrigation branch, volume over increased pressure. Around here we reduce the pressure for irrigation piping to 30 psi. anyway.

Properly sized, fully reamed piping is usually the answer. Keep it simple. Good luck!

 

[JudgeDroid]

Thanks for the responses. I was under same impression that increasing pressure to sprinkler is not good. I had the water utility guys come and they checked water pressure at the main line. It was 62psi and I am 60 psi when it enters my house by the meter. Its 3/4 all the way from the main line. Its a long run and goes in concrete slab so its cost prohibitive to change to 1". The meter was replaced last week with a new one (digital from old analog dial). The GPM increased by half gallon or so.. pressure remains the same.

 

[Valveman]

How many GPM's does your sprinkler use, and what is the pressure while they are on. You should be able to get almost as much at the house as the sprinklers are using.

You can't just add a pump and pressure tank if it will starve the incoming line. You can't pump water you don't have. But if the volume is there and the pressure is low, a pump can increase the pressure. As long as you have 20-30 PSI coming to the pump, even a small pump (1/2HP--3/4HP jet pump can boost the pressure to 60 or more. But if the pressure is already 20-30 PSI at high flow, it will be zero or less when you start sucking on it, which isn't good.

A 1/2 or 3/4 HP jet pump with a Pside-Kick kit to control it might cost 800 bucks or so, and you can plug it right into a wall plug if you want.

 

[Jadnashua]

IF the pressure drops dramatically when you run the sprinkler branch, you have a volume problem, not a pressure one. You'd need a much larger storage tank than 15g to overcome that problem if you can't make the supply line larger. Static pressure is one thing...pressure while flowing is another.

 

[JudgeDroid]

Thanks for all the responses. My installer is going to use 1.5" and 1" lines for the sprinkler system. We will start with this combination. No pumps or storage tank for now.

 

[JudgeDroid]

Add a loop in ur plumbing. Will keep things up to gpm when other things our running

Hi.. Can you please clarify how loop can be added? My house was built in 50s.. And plumbing is running through the slab. Thanks