# PVC line size vs supply size



## raymond (May 4, 2018)

https://www.irrigationtutorials.com/should-pipe-be-the-same-size-pipe-as-the-sprinkler-inlet/

At my house I think I have a 3/4 inch supply line I'm about to tap into for a new sprinkler.

In YouTube videos and on the Irrigation Tutorials link referenced above they mention having lines either the same size or larger than the supply line.

Is the performance of a larger line (a 1 inch line in my case) really worth the money going larger pipes? In my case 3/4 to 1 inch piping maybe would be $60-100 more money for the pipe for the project, not a crazy number. But it starts to affect other project items like backflow preventer etc.

Thoughts?


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## SCGrassMan (Dec 17, 2017)

I would do 1".

Get the ZURN 975 XL reduced pressure 1" backflow and the Rachio gen 3.

All my personal opinion


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## Grass Clippins (Apr 30, 2018)

@raymond What is the supply line made of? I'd bet it's polyethylene.


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## raymond (May 4, 2018)

Grass Clippins said:


> @raymond What is the supply line made of? I'd bet it's polyethylene.


My house is 50 years old (literally) and I'm 98% sure it's galvanized steel.


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## raymond (May 4, 2018)

SCGrassMan said:


> I would do 1".
> 
> Get the ZURN 975 XL reduced pressure 1" backflow and the Rachio gen 3.
> 
> All my personal opinion


Daddy big bucks here! Lol. I was planning on just getting a double backflow preventer... little cheaper (closer to $100 vs the $200+ for the model you mentioned) plus it can be buried which is a huge plus. I recognize that the irrigation tutorials says this isn't good enough for potable water, but my local city water requirements says it's fine. It using a double backflow frownee upon on TLF?


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## SCGrassMan (Dec 17, 2017)

Save up the extra $100 and then get the good one.


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## raymond (May 4, 2018)

Anybody have experience with the Apollo vs the Zurn back flow preventers.

https://www.homedepot.com/p/Apollo-1-in-Lead-Free-Bronze-FIP-Reduced-Pressure-Backflow-Preventer-4ALF205A2F/307753775


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## unclebucks06 (Apr 25, 2018)

3/4" wont provide many GPMs under 5ft per second velocity.


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## datcope (Oct 29, 2018)

I grew up being taught that in order to get the flow rate up, we installed a 1 1/4" main line around the project as soon as we came out of the anti-siphon valve.


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## raymond (May 4, 2018)

Will it make a significant difference if I begin the 3/4 to 1 inch pipe size before or after the backflow preventer? My supply line is only 3/4. I'm weighing options for the backflow preventor so need to understand if there's a different of having the larger 1 inch pipe before or after matters


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