Register free!


Reply
 
Thread Tools   Display Modes
  #1  
Old 05-23-2013, 12:46 PM
goodmatt78 goodmatt78 is offline
LawnSite Member
 
Join Date: Mar 2010
Location: ohio
Posts: 18
Tuning new system - PR questions

I just installed a system using PGP rotors and red nozzles. I have static of 45 psi and 12 GPM (on interior 1/2" line hose bib)...exterior main line is 1" and we are tapped in a within 1 foot of that entering the house with 1" to supply the system.

I balanced the system and plan to do an audit this weekend to better determine the watering duration.

Currently I use the following nozzles:

90deg - #2
180deg - #4
270deg - #5-6
360deg - #7

Irrigation tutorial suggests: #3,#6,#8,#9

I am almost exactly 75% of the GPM recommended on irrigation tutorials.

Currently running 25min/zone w/ 6 zones and 4 heads per zone. My most exhausting zone is at 8.4 GPM now (charted for 40psi).

I plan to renozzle a zone this weekend to see if I can bump up nozzles without ill effects from pressure drop.

Currently I show about 40 psi on a hose bib while running the system. I figure I am probably already below 35psi at the heads. Sound about right? Therefore, I am not sure if I can up my nozzles more.

What PR should I be aiming for. Around .5 in/hr?

Thanks.
Reply With Quote
  #2  
Old 05-24-2013, 10:41 AM
Kiril Kiril is offline
LawnSite Fanatic
 
Join Date: Jun 2007
Location: District 9 CA
Posts: 18,318
There is no PR to aim for. Zones should have been designed per available flow and area to be irrigated, with a little overhead for flow and pressure fluctuations. While you can play with different nozzles a bit after install using the adjustment screw, that would only be to fix poor design. The rest of it (ex. PR) comes into factor when scheduling the controller.

Also, don't know what you mean by "75% of the GPM recommended on irrigation tutorials". Assuming all the radii and nozzle pressures are the same, the design GPM per nozzle should be an exact multiple of the output for your 180 degree arc on the other non-180 arcs, with a few exceptions. You will probably never achieve this exactly with PGP reds, but you need to get as close as you can with the nozzles provided without having to use the adjustment screw excessively.
Reply With Quote
  #3  
Old 05-24-2013, 12:15 PM
Mike Leary's Avatar
Mike Leary Mike Leary is offline
LawnSite Fanatic
 
Join Date: Mar 2007
Location: Cactus Hug, Arizona
Posts: 20,574
Quote:
Originally Posted by Kiril View Post
you need to get as close as you can with the nozzles provided without having to use the adjustment screw excessively.
Ditto what you said. I've seen PGPs dogged-down so far that they only threw 5'!
Reply With Quote
  #4  
Old 05-24-2013, 04:15 PM
goodmatt78 goodmatt78 is offline
LawnSite Member
 
Join Date: Mar 2010
Location: ohio
Posts: 18
75% meant that it is suggested to use 3,6 and 9 nozzles (since you have wind issues with the smaller nozzles) and I am using 2,4 and 7. Yes I am matched but using smaller nozzles than suggested.

I did a quick audit last night and I am putting down about .3"/hr and keep 40psi at an open hose bib while running. I will try nozzling up to 3,6,9 and see how it does. I think my heaviest zone will still around 11GPM.

I would like to get high enough PR to only water 4 times a week.

As for the diffuser, screw I have them set to just nick the stream, but not shorten the radius.

Thanks for the replies.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump






Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ©1998 - 2012, LawnSite.comô - Moose River Media
All times are GMT -4. The time now is 06:22 PM.

Page generated in 0.06469 seconds with 9 queries