water pipe corrosion

My fittings on the six inch underground irrigation system are rusting out. I'm digging up the third one as soon as parts come. This is a totally awful
terrible job. Unless you like doing Mexican backhoe in a mud hole.
Anyway, the fittings are all a weldament of six inch and four inch by 1/8" wall steel tubing. I'm getting a small rust hole right at the bottom of the pipe where water sits during the off season.
Anybody know of a corrosion preventative or something I could apply to the steel like a zinc based paint maybe. Other ideas?
Karl
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Karl Townsend wrote:

Replace the system with common black poly. No rust. Cheap and easy.
--
Steve W.
(\___/)
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They don't make custom fittings out of plastic in six inch diameter. At least I've never seen them.
Karl
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What do you mean by custom? You can definitely replace it with PVC and probably adapt to whatever you need:
http://www.idswater.com/water/us/jm_manufacturing/polyvinyl-chloride-pipes/13473_0/g_supplier_2.html
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http://www.idswater.com/water/us/jm_manufacturing/polyvinyl-chloride-pipes/13473_0/g_supplier_2.html
You found the pipe, mine's the six inch PIP. The pipe is buried in the field road. Now, just try to find an offset riser to put the three inch shut off valve beside the road at soil level. Don't forget the winter drain valve. Trust me, it ain't made.
Karl
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The valves we use in the northeast are always in line with the pipe and require a long-ass bar to operate.
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On Tue, 20 Apr 2010 13:49:00 -0500, the infamous "Karl Townsend"

Can you run out a pair of 3- or 4-inchers instead? Flexi links to half a dozen ABS pipes? Aluminum pipe? Stainless steel? (Only a couple hundred thou more, eh?) Teflon lined pipe available?
-- "I think you very well may see a revolution in this country and it will not be a revolution to overthrow the government," he said. "It would be a revolution to restore government to its constitutional basis." --Rob Weaver on VoA, 4/19/10
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On 4/20/2010 11:39 AM, Karl Townsend wrote:

http://en.wikipedia.org/wiki/Cathodic_protection
How about sacrificial anodes bonded to the pipe at intervals?
--Winston
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Good idea, and I see Mcmaster sells them. I'll put one on it.
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Karl Townsend wrote:

If you can access these parts out of the system, and since it's non-potable water, I'd look at a coating like those made to coat inside a gas tank.
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Do you have a name. Need more direction to know what to order. I'd to order it yet today.
Karl
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Karl Townsend wrote:

Here are a few possibilities:
http://www.kbs-coatings.com/Tank-Sealers_c_7-1-0.html
http://www.caswellplating.com/aids/epoxygas.htm
http://www.justgastanks.com/store/index.php?main_page=index&cPath !_335
http://www.summitracing.com/parts/SUM-900056 /
You can probably get something at a local auto parts store.
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How about Pick-Up Truck bed liner goo, like "Rhino"?
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On Wed, 21 Apr 2010 02:15:29 -0400, the infamous "Buerste"

First, learn to type in complete sentences. <bseg>

Even if it did work, it's naturally sticky and would give the moving water fits as it went through the pipe. Can you say "turbulence"? I knew you could.
Hmm, Slick50 treatment? Connect pipes, pour in Slick50, rotate long section while heating, pour out Slick50. Hmm...
-- "I think you very well may see a revolution in this country and it will not be a revolution to overthrow the government," he said. "It would be a revolution to restore government to its constitutional basis." --Rob Weaver on VoA, 4/19/10
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On Wed, 21 Apr 2010 06:11:54 -0700, Larry Jaques

The oil field people usually demand that after a "pig" is run by driving it with water, the water either be completely removed or the pipe be left completely full.
I am assuming from your posts that the pipes require draining to prevent freezing but I wonder whether, after draining as best as possible an air compressor could be connected and "blow down" the pipe for a few days might not prevent further corrosion.
John B. Slocomb (johnbslocombatgmaildotcom)
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    [ ... ]

    How about pulling a vacuum on the pipes instead -- assuming that they can take the compressive forces of pulling a vacuum on the pipe. This will cause the water to evaporate relatively quickly -- assuming that you have a way of sealing the other end of the pipe.
    Enjoy,         DoN.
--
Email: < snipped-for-privacy@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
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I'm sure that any pipes that can take an internal pressure of 50-80 psi can handle a vacuum without imploding. However, that would be a very large volume of water to evaporate. If you do try this I recommend watching a vacuum gauge as you pump down as you will get boiling and then freezing and you will see a plateau at 5-15 torr during boiling and evaporative cooling. Keep pumping until the pressure falls below maybe 5 torr (where the amount of ice starts to become large), and then vent the system to air and allow time for the ice to melt before you do another cycle.
Karl, I know you said that all the special risers and valves you need are not available in PVC, but how about using PVC pipe for the main runs and adapting to iron for all those fittings? When they rust out you can replace them but you won't have to dig up all the long runs of pipe, at least.
----- Regards, Carl Ijames
| Voice (all times): (703) 938-4564

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On 23 Apr 2010 01:34:17 GMT, the infamous "DoN. Nichols"

Or a -hot- air blower down the pipe for a couple of days, then sealing it tight.
-- ...in order that a man may be happy, it is necessary that he should not only be capable of his work, but a good judge of his work. -- John Ruskin
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On Thu, 22 Apr 2010 20:00:40 -0700, Larry Jaques wrote:

...
Since the irrigation-pipe volume is around 20 cubic meters per km, running a hot air blower might be far more practical than either a compressor or a vacuum pump or a surplus dry nitrogen generator. I imagine the underground pipe length is between 100 and 1000m, for 20 acres of orchard. A picture of some surface pipe in a strawberry patch appears in the first web document (a .pdf file, in spite of its .aspx extension) listed at <http://www.google.com/#q=growers15.aspx .
--
jiw

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Karl Townsend wrote:

Check out POR 15 , they have several products that might work for you .
--
Snag
"90 FLHTCU "Strider"
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