SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

It is very rare that a 5/8 meter is feeding a 1-1/4 line, unless the design has very long runs. One extra zone makes for less flow per zone, makes for smaller pipe needed.

put in five-inch pipe if you want - no never-mind to me

you are supposed to use friction-loss tables to make this decision - run the numbers

From a cost perspective, you want to use 1" pipe... if you can.

1/2", 3/4" and 1" PVC are the most common sizes used/sold (at the big box retailer). Since these are the highest volume (in sales), they have the best prices. Therefore, you are getting the most bang for the buck with 1" PVC. Once you go above 1", not as much is sold. As a result, the 'discount' price you get at the big box retailers isn't as good for this lower volume item.

But as Boots points out, you've got to do the math. If 1" PVC pipe at your designed flow rates creates too much of a pressure loss, your irrigation system won't work correctly and rather than saving money using 1" PVC you will loose money because it will all be a waste.

If you need a table, you can find one here on page 4 for Sch 40 PVC pipe.

If you use 1" pipe, and your system is designed to run at 12 gallons per minute (assuming your system can supply that much), then you are going to loose about 7psi on a 200' run (3.36 *2). Increase pipe size to 1-1/4 and pressure losses are <2psi. But if you design for 9gpm, then your 1" pipe will only loose 4psi on a 200' run.

go to a irrigation supply store and pay half of that for 20' sticks

Quoted from "aswilburn"

At Lowes in S.C. 10FT SCH 40 1-1/4 is $4.71 a stick, guess what 10ft SCH40 1'' stick is the same price, guess u guys know what I'll be useing then!
Thanks guys, your patience and knowledge is priceless

The sticks might be the same, but make sure to check the price of the fittings. That's where I've seen the big difference in prices. Then again, I have not checked prices since I installed my system three years ago.

When a system is being installed with poly pipe, it would be extremely rare to see 1-1/4 inch tubing. It isn't just the cost, but rather the additional set-up time to pull the larger tubing. Much easier to invest in an additional zone, if need be.