# Trying to understand (drip) lines, sizes, and types.



## penright (Apr 6, 2020)

The subject is my question but I feel like there needs to be some context.

All these (pictures) were found in the box store's irrigation section.
I have moved some popup's in the past and I used 1/2" that was a thick rubber (green line). 
The guy who planted two big (100" truck) oak trees, used a drip line that we buried just below the ground for the trees. He said to use it for the first 2 - 3 summers and then I should not need it any longer. It was 1/2" (?) more of a thinner black plastic-type. Since it was temporary it is being fed from the house hydrant. We stuck a couple of 1/4" emitters off of it.

I wanted to do some more drip irrigation so I thought the thinner black is what you should use. I bought some 1/2" and 17mm fittings. I was expecting 1/2" to be .500" and 17mm to be .669" both fit loosely in the 1/2" black. I have done a lot of searching on 1/2" vs 17mm and did not see anything that directly said what is different between 1/2" and 17mm. 
It does appear that 1/2" is all over the place in ID/OD.

So how do you make sure pieces will work together?

One interesting thing I learned while searching this, is most threaded specs are mnpt. The m is male part, while fnpt, the f is female. And 1/2" mnpt is not 1/2" OD but is .840". This has not been an issue for me in the DIY irrigation world since it seems the two sizes are 1/2" or 3/4" and there is enough visual difference to know the difference without measuring. I guess not the case with drip lines.


----------



## jayhawk (Apr 18, 2017)

Tree drip line ...yeah, not much roi there

Thick rubber (green line)is generally for the 'last mile' between irrigation pipe and the popup body.

Are u leveraging a irrigation zone or going off the house bib ?

I just went through multiple trips to Ewing, Depot to drip my small garden. I'm off a timed hose bib. Here, the 1/2 is brown plastic like as a trunk where you ultimately poke to add 1/4 " rubber lines (branches) to drip emitters.

You lost me on all the fittings talk


----------

