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old_desert_rat

Advice on PVC Pipe vs Black flexible Tubing

old_desert_rat
18 years ago

I am on a well on 2 1/2 desert acres. I have 165 trees and shrubs I have planted in the last two years. At present I have 16 zones (manual) on 1/2" black flex tubing with 1/4" flex spagetti with 1 emitter per plant. I water for 1 hr every three days and plants are doing well. My well output water line is 3/4" PVC (schedule 40?) for a water line to my spigots. I hook to my spigots with the 1/2" black flex tubing. I need to install an automated irrigation line with controller(s), Valve boxes, etc.

Question 1: Should I use 3/4" or 1" PVC (solid pipe) or 3/4" or 1" black flex tubing for my zones off the valve boxes?

Question 2: Would there be more of a pressure problem using 1" rather than 3/4" coming off my 3/4" main water line?

Question 3: Valve boxes (zones): I don't know what size these boxes come in, but obviously you can only get so many zone valves in a box and be able to work on them.

I am a real novice when it comes to irrigation, so I would appreciate any advice I can get on controllers, zone valve/boxes, size and type of water lines off these zone valves, and any other pertinent information.

Thanx,

Bill

Comments (5)

  • mtorzews
    18 years ago

    The size of the pipe is based on required flow rate, length of the pipe, and available static pressure. The choice in PVC or poly line is more of personal choice. Both work. Poly line is used more often in cold climates because it performs better than PVC if water freezes in it.

    Check out this website. This is where I learned how to design my system.
    http://www.irrigationtutorials.com/

    Okay silly question - If the current lines work why not keep using them and just change the manual valves to electronic valves?

  • gardenracer
    18 years ago

    If you have gopher or underground rodent problems, pvc would be best. The poly tubing tends to get chewed on.

  • hpywndrr_yahoo_com
    16 years ago

    Good thread on Poly vs. PVC.
    When I first installed my water lines I considered poly, but figured it to be a 2nd class solution as it was cheaper... Now 22 years later I'm having underground leaks from the 1' sched_40 PVC breaking. This is in the Pacific NW, not real cold but very occational quakes. The problems don't seem to corellate with quakes though...
    When doing mods/repairs, found the PVC has become brittle as compared with when it was new. I guessed at the time the glued and threaded fittings to be more reliable with PVC, but are the really? I'm ready to replace the 22 year old PVC. The ease of installation of black poly would be great as I too have rocks/stumps to go around.
    BUT BUT BUT can't help be suspicius of those brass barbed fitting held only in place with a SS hose clamp.
    Are there any tips/tricks to installing the larger (~1'+) black poly to make the connections as reliable as PVC or make the job go easier? Any situations to avoid with black poly? (I've got to go ~200' through-the-woods from pump house to the area needing water) cheers

    Here is a link that might be useful: Garden Web

  • devinglanz
    16 years ago

    PaulW
    there is no reason to use brass insert fittings on poly pipe it will cost you big $. just use the plastic ones thats all i use on installs and dont use the regular hose clamps it will take you forever, get some otiker crimp clamps. there is no reason to be suspicius of poly I work on 30 year old poly sytems with little or no problems. if you are really woried obout leaks you could use "Lox On" strap claps made by ideal if you have a presurized main line. also make sure you size your pipe properly especial on long runs because there will be a lot of fricion loss. you can find the friction loss charts in the back of the sprinkler manufacturer catalogs or online somewhere.

  • Sherwood Botsford (z3, Alberta)
    16 years ago

    I now have nearly a mile of black poly. I lay it on the surface where there's no mowing, notch into the sod so it's flush with the surface where I mow. I open all the valves, and lay the hosebibs flat in the fall. I've got a few strategic couples in low spots that I break open to get most of the water out.

    Spend the extra money for nylon barbed fittings. The best ones are black, glass filled (short bits of fiberglass) Second best are the white nylon ones. They will degrade in the sun. You may want to paint them or bury them in mulch.

    The grey ones are brittle, and will break easily.

    The larger sizes of black poly are a bear to get coupled tightly. I now take a tea kettle and a camping stove and get the pipe steaming hot before putting the fitting in. 1.5" I now double clamp (2 hose clamps.) If you can keep the system under 20-30 psi you don't need hoseclamps on 1/2" insert fittings.

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