Drill Stem Pipe Tower

[dg5267]

Will 2-3/8" drill stem pipe work as a guyed tilt-up tower pole for a three blade 11 ft. diameter home made genny? Are there any good formulas to use to get this right the first time?

I'll probably go up about 30 ft. initially with hopes of reaching a final height of 6 ft.  The expected maximum wind is 70 mph. The genny will furl at around 25 mph.  

[Todd a]

I would not trust it.  An 11' turbine has a pretty large surface area.  Even with a good furrowing system you are going to take a lot of strain at anything close to 70mph (even at 30mph).  You would need a lot of support so it will not flex.  With an 11' turbine you are looking at about a 6 foot span above the highest guild wire.  That means with a 30' tower you will have one set of guild wires at 24'.  I would not trust one set and would likely put another set at 12'.  The only problem is at the 24' point you will have a lot of torque trying to snap that last 6' section clean off.  I would reinforce the tubing around that 24' guild wire.  Maybe a 4' piece of thick walled steal tubing welded over the well piping.

All that said you are still looking at a pretty heavy piece of hardware on top of this tower.  I personally would like to see a bigger tube to use.

[jmk]

Are you talking inside dia.? I am useing the pipe with that inside dia. and about 7/16" wall. The outside dia is actually about 3 1/2". I have a 12' mill on a fifty four foot tower with that stuff. It's really heavy pipe, about 400 lbs for 21'. If you are talking about that stuff then it is plenty strong it's just plenty heavy!

[RobC]

Hi

 I use 2-7/8" drill stem on my 11ft mill and it flexes quite a bit at the top. If you use your pipe I wouldn't go over 10-intervals without guys. My tower because of the strength of the pipe was guyed at 30ft the first time, big mistake a micro burst came though and bent it like wet spaghetti. The turbine mowed down part of a shrub on its way to the ground LOL. RobC  

[Rover]

2 3/8" pipe sounds like regular 2" schedule 40 steel pipe. I agree with everyone else that said not push a span more than 10ft. Even on my small pma, I get quite a lot of bend. One thing I do is to fill the pipe with an epoxy/vermiculite mix. once it hardens, it adds quite a bit of regidity. Also makes it harder for the pipe to break as it has to also compress and crack the filling , which is like rock.

It does add a tad to the weight though.

[dg5267]

I checked again. The pipe has an OD of 2.875 so it's the 2-7/8 drill stem tubing.

[dg5267]

I checked again. The OD of the pipe is 2.875 in.  It is 2-7/8 drill stem pipe.

[jmk]

 Rover, if you fill your pipe, how do you get your wires down?

[Rover]

This time I did I ran the wires then expoxied, I had a brushed collar at the time so didn't worry about wires twisting. Since then, like my 30 ft tower, I only fill the bottom 3rd and run the wires inside , and then outside.

[Tritium]

I am still confused. Is this Drill Stem or is it oil field pipe? Drill Stem has a very thick wall usually about 1/2" thick and very special conical very course threads at 1 end and the other end is a bell end. Oil field pipe has regular pipe threads and is not that thick walled at all (more like somewhere between sch 40 and sch 80).

Thurmond

[RobC]

If this is the same pipe I use it has a 3/4 rod in it and a pump at the bottom when it is installed in an oil well. Most people mistakenly call it drill stem including myself. It varies in wall thickness and sometimes the pump/sucker rod has worn almost all the way though. If it were new I think it would be almost almost sch 80. Its not the greatest pipe to use. RobC

[dg5267]

The receipt from the metal company indicates drill stem pipe.  I don't know any better.  It's certainly does not have 1/2" thick walls.  It's closer to schedule 40 pipe. It does have a belled end with threads.  If drill stem pipe must have a thickness of 1/2", I guess it's oil fieled pipe.