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tmc_31
07-10-2010, 12:29 PM
Hi again guys,

One more sort of OT question. This question deals with hydraulics, specifically porto-powers.

What I want to do is separate two light pole sections. The light poles are galvanized steel approximately 70’ tall (in two sections) and about 20” in diameter at the joint. The poles are tapered and the joint between the two sections is a slip fit joint 1.5’-2.5’ long. Typically the poles are assembled by lubricating the pole sections with dishwashing liquid, then sliding the two sections together and pulling them together with two 3 ton cable hoists. The top section including the light fixtures, crossarms and top pole section can weigh up to 4 tons. This pole would have been sitting out in the weather for up to 10 years or so.

I want to separate the pole at the slip joint without damaging the top section of the pole. I am thinking of using two porta power rams with a single mule (hydraulic pump) to separate these sections.

My question is how large a porta power do I need (or how much pressure will it take to separate the sections)? Will a single mule power both rams to full capacity? Is there a better way to do this?


Tim

Boucher
07-10-2010, 02:07 PM
Plug both ends. Adjust your cutting torch then snuff the flame and run the gas mixture into the cavity then ignite.

Then there is black powder or even a little calcium carbide and water.

Sometime I will tell you the story about putting some carbide in a hollow in an oak tree with a little water to get a squirrel out.

Arcane
07-10-2010, 02:51 PM
If they are wedged together that tight, I think you might need a "shock load" to separate them. I would suggest applying a considerable bit of tension via large winches (or whatever is handy) to pull the ends in opposite directions then whale the tar out of the large flange at the bottom with a sledge hammer and see if that will break it apart. Once the "stiction" is broken they should come apart quite well.

This was the method we used to use to separate street light standards which have a straight section and a "gooseneck" section except they were just a fraction of the size of your standard and we didn't need to tug them apart, the sledge hammer was enough to do it all. Good luck! :)

doctor demo
07-10-2010, 03:06 PM
I want to separate the pole at the slip joint without damaging the top section of the pole. I am thinking of using two porta power rams with a single mule (hydraulic pump) to separate these sections.
My question is how large a porta power do I need (or how much pressure will it take to separate the sections)? Will a single mule power both rams to full capacity? Is there a better way to do this?
Tim
Tim, You didn't say weather You needed to save the bottom section. If not just cut it off below the joint and slice it open with a torch or grinder with a cut off disc.
If You have to save both and can make them water tight lay the pole down and fill it with water and attach a pump that is used for expanding trench shoring and pump the two halves apart .

Steve

tmc_31
07-10-2010, 03:17 PM
Boucher, you redneck!

That would get them apart alright. Don't know how the locals would like it. We used this method (fuel) in our tater guns until the schedule 80 pcv pipe started to blow apart (damn cheap a$$ Chinese glue).

Arcane,

Your point is well taken about applying a good whack when the pressure is on. I was trying to separate one of these poles with it standing in place a few years ago. The crane guy said had 5000lb on it and that was as far as he wanted to go. I told one of my guys to whack it with a 10lb sledge. When he did the pole jumped apart about 5' then settled back down on the stub. All I could see of my hand was a trail of dust!!

Did you work for an electric utility? I worked for West Texas Utilities for 26 years. Started out maintaining streetlights.

Tim

Arcane
07-10-2010, 05:57 PM
Yes tmc_31, I worked for 35 years as a Journeyman Lineman for Sask Power, 16 years of them as a District Officer. Over that period of time, I managed to do just about everything related to power distribution. The four little words "and other related duties" in my job description made sure of that! It was an excellent occupation and one I am proud to have done.

tmc_31
07-10-2010, 06:58 PM
Arcane,

I worked as a Line Serviceman for 10 years and then got into management. The last 11 years I was with them I was in Marketing & Technical Services as a Lighting specialist. I also found that working for WTU was some of the best I have ever done.

All,

I had another thought about how to get that base separated from the top pole section. Understand that we have taken the pole down and it is laying horizontal on saw horses. An associate suggested cutting the base section off about two inches below the joint, then slitting the left over piece inside the top section with a torch or plasma cutter. While I am sure this method would work, I am afraid of damaging the inside of the top section. It occurred to me the I might be able to build a "mill" that would attach to the inside piece and run a 3/8 carbide end mill down it to create the slot. DOC would be just the thickness of the pole section. I am not sure how best to attach the mill bed securely to the inside section. Does this idea have any merit?

Tim

boslab
07-10-2010, 09:01 PM
Plug both ends. Adjust your cutting torch then snuff the flame and run the gas mixture into the cavity then ignite.

Then there is black powder or even a little calcium carbide and water.

Sometime I will tell you the story about putting some carbide in a hollow in an oak tree with a little water to get a squirrel out.
That was my first fishing pole, a scew top glass bottle, thicker the better [they were bloody thick, but not as thick as us] cup of carbide and a cup of gravel, gravel in the bottle, then carbide drop of water, screw the top on shake and throw the bottle in to the local Trout pond.
Wait till it blew then wade in and pick up the fish. The gamekeepers were not amused.
mark
BTW get 2 pipe vices and stick a ram between them to slide the poles apart, a little heat helps

Arcane
07-10-2010, 11:53 PM
If you want to slit it, howzabout a skillsaw with a metal cutting blade? Easy to set to a predetermined depth and it won't wear down like a cutoff blade would. (get earplugs too! :D)

tmc_31
07-11-2010, 12:01 AM
Boslab,

The two pipe vises with a ram is essentially what I had in mind. I plan to use 4 pipe vises (or something similar) with two rams, one on either side of the pole so as to exert equal force on either side of the pole. The question is how big do the hydraulic rams need to be to break this thing apart. The largest porto powers I've found are 20 tons. This would be 80,000 lb of force.

Tim

tmc_31
07-11-2010, 12:09 AM
If you want to slit it, howzabout a skillsaw with a metal cutting blade? Easy to set to a predetermined depth and it won't wear down like a cutoff blade would. (get earplugs too! :D)

That is a thought Arcane,

I have successfully cut some sheet metal with a carbide tipped wood blade but this stuff can be up to .250 thick. Is there a metal cutting blade that will fit in a skilsaw that will cut this stuff? I have a 7-1/2" worm drive Skilsaw that I think will fit inside the pipe.

Tim

wierdscience
07-11-2010, 12:20 AM
If you can get a tug on it and hit it with something like a demolition hammer while it's under tension that might do it.

oldtiffie
07-11-2010, 12:25 AM
20 tons maximum on a PortaPower is about right, but be aware of the pressures on the pump, ram and hoses - ~700 Bar or 10,000psi:

http://i200.photobucket.com/albums/aa294/oldtiffie/Hydraulics/Hydpresspressure1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Hydraulics/Hydpresspressure2.jpg

Arcane
07-11-2010, 12:36 AM
A quick Google check brings up several hits for "metal cutting skill saw blade" including this one (http://www.lenoxtools.com/pages/Product.aspx?id=MetalCuttingCircularSawBlades) for Lenox brand blades. (I'm partial to Lenox brand for certain cutting tools). I noticed their website even has a Material Safety Data Sheet complete with an Emergency Telephone Number. :rolleyes: :D

tmc_31
07-11-2010, 01:08 AM
Arcane,

After reading your post I also searched on metal cutting blades. Search led me to the Evolution website. Just one of many but it shows real possibilities.

Tiffe,

Thanks, I became aware of the pressures involved after reading the specs on the Blackhawk Automotive Porto-Power website. Until I read that I had no idea that a hand pump would deliver that much pressure. Do you have any insight as to the results of trying to run two rams off of one mule? It seems to me that I should get the full 20 tons of force, just not full stroke as the mule will run out of fluid. Am I off base here?

WS,

The demo hammer may be a good idea. better than a single whack with a 10lb sledge.

Thanks for the advice guys,

Tim

oldtiffie
07-11-2010, 03:36 AM
Arcane,

.................................................. ...........................................

Tiffe,

Thanks, I became aware of the pressures involved after reading the specs on the Blackhawk Automotive Porto-Power website. Until I read that I had no idea that a hand pump would deliver that much pressure. Do you have any insight as to the results of trying to run two rams off of one mule? It seems to me that I should get the full 20 tons of force, just not full stroke as the mule will run out of fluid. Am I off base here?

.................................................
Tim

Thanks Tim.

Having two cylinders on one pump is a problem as the fluid will take the path of least resistance - ie the one that has the lowest resistive pressure. If that is the case, getting the cylinders to work precisely together will be a problem.

I'd be inclined to have two independent systems as not only will the rams move quicker (ie don't have to share pumped volume) but will require double the oil for the same ram displacement. Twin/dual systems will give a lot more independent control.

It is quite possible to connect two/dual rams to one pump and get effective independent motion and control, but I doubt that its worth it.

Porta-Power rams are not all that heavily built due to the portability requirement and so are not all that long - particularly so at higher pressures and forces.

My "Mechanics" porta-power (clone) set has cylinders that are rated at 2, 4 and 10 tons but they are pretty small.

https://www.machineryhouse.com.au/Products?stockCode=A364

https://www.machineryhouse.com.au/Products?stockCode=A367
I have a 8 (long) ton - 8,000Kg - "air over hydraulic" ram on my 1 ton shop engine hoist. It is very solidly built and has a long stroke. All I need is a static oil supply and a 90 psi air supply. It works very well. Two of those may suit your purpose very well.
I retro-fitted mine and as I have the original ram/cylinder,

https://www.machineryhouse.com.au/Products?stockCode=J032

I could use them together as separate units as they are actuated/powered independently.

This is my air-over-hydraulic unit:
https://www.machineryhouse.com.au/Products?stockCode=J033

Cost AUD150 x 0.85 ~ USD130.

The ends of both rams/cylinders are fitted for a yoke so that they act as "pin-pin" columns and are not restrained or acted upon by other than axial forces.

The yokes are standard shop engine crane models that will be seen on most cranes and are easily, quickly and cheaply made.

I hope it helps.

tmc_31
07-11-2010, 09:16 AM
Tiffe,

Your point about the rams not acting evenly is well taken. I would rather not have one ram pushing too much and cock the top section over and make things worse. So two independent systems may be better. It should only take 2-3 inches of stroke to break these poles loose. I think the shorter rams will be more stable. Keep in mind that the rams will be strapped to either side of the pole. If the ram is too long I am afraid it could bow out under pressure.

thanks,

Tim

RancherBill
07-11-2010, 10:07 AM
Here's some random far fetched solutions. I assume the pole will be on the ground.

Get a tiger torch, http://www.tooltimesupplies.com/assets/images/fans_heaters/1395_TigerTorch.jpgpressure washer, sledge hammer and a bottle jack.

Place the pole on a support on either end. In the middle place the bottle jack. Start pressure washing into the joint with a soap mixture, then apply heat unevenly to one side of the pipe, hit with sledge and then pressure wash again. You can wiggle the joint up and down with the bottle jack. It sounds like a big job, so I am assuming there will be two big trucks. Attach one end of one truck, The other connect to the crane truck. It would be a real bonus if that truck had pulleys so the it's cable could be rigged low like a winch.

Optional upgrade procedure, fill with gunpower while using Tiger Torch :eek: .

tmc_31
07-11-2010, 10:20 AM
Rancherbill,

Sounds like either you and Boucher are in cahoots, or explosives are the universal remedy. I would not want to be in either truck when that thing came loose. It is bad form to get the hands hurt.

I all seriousness though, the idea of using a pressure washer to force soapy water into the joint may have some merit.

Thanks,

Tim

RancherBill
07-11-2010, 12:55 PM
I'm glad I could contribute my own "random far fetched solution".

I am happy that one of the five concepts presented had merit. :) :rolleyes:


I always think of the gunpowder solution. In Canada I can't get it, I don't have a firearms licence. I like the YouTube videos of creative uses for gunpowder. I paricularly like the anvil launching ones. I could envision a lamp post separation one. The thought of the end section of light shooting straight up in the air hundreds of feet is pretty appealing.

Or you could make the worlds largest potato cannon and put a 100# sack of potatoes in at once. :eek: Just imagine the mushroom cloud of hundred of potatoes showering the area for a couple of hundred foot radius. :eek:

tmc_31
07-11-2010, 02:05 PM
I'm glad I could contribute my own "random far fetched solution".

I am happy that one of the five concepts presented had merit. :) :rolleyes:


I always think of the gunpowder solution. In Canada I can't get it, I don't have a firearms licence. I like the YouTube videos of creative uses for gunpowder. I paricularly like the anvil launching ones. I could envision a lamp post separation one. The thought of the end section of light shooting straight up in the air hundreds of feet is pretty appealing.

Or you could make the worlds largest potato cannon and put a 100# sack of potatoes in at once. :eek: Just imagine the mushroom cloud of hundred of potatoes showering the area for a couple of hundred foot radius. :eek:

I didn't know there were rednecks up in Canada!! Watchout World we're everwhere (and lookin fer sumpin to blow up)

Tim

krutch
07-11-2010, 02:15 PM
I take it from the postings that you will not try to save the bottom section. Can you collapse it in on itself to deform and release it from the top? I've done this on similar applications, of much smaller sized stuff, though.

winchman
07-11-2010, 03:35 PM
We had dozens of poles like that for lightning protection around the explosive processing buildings where I used to work. I watched a lot of them being installed, and I had a chance to talk with the project engineer handling one of the jobs.

Nothing was applied to the joints as the sections were lifted and slipped together. The PE told me the rocking motion of the wind on them would work them together so tightly that the joint would eventually become stronger than a weld.

Based on that, I'd say you're not going to have much luck getting them apart short of cutting them.

darryl
07-11-2010, 04:00 PM
Did somebody already mention setting up two trucks, one with a winch- I'm also assuming the pole is horizontal, and you can set it up to stretch on it and wiggle it up and down in the center as Rancherbill suggested. I was going to suggest wicking in some penetrant as well- only difference is that I'm not going to suggest explosives :) though it would be fun-

What I am going to suggest is to forget about separating the sections and instead re-purpose the pole. If that were laying in my yard, I would have figured out how to install it vertically and mount a wind power generator on it. At the same time I'd have built a cable operated viewing platform that I could ride whenever the whim struck me. Then of course I'd have to have a lightning rod going skyward from the top, and then probably have some kind of tourist attraction contraption up there so the city wouldn't make me take it down :)

tmc_31
07-11-2010, 05:00 PM
Hey Guys,

Krutch,

I also thought about that. I could drill a 3/4 hole through both sides of the bottom section, insert a bolt all the way through and tighten a nut until the pole collapsed in on itself. My concern with this method is distorting the top section at the joint while doing this. I am going to have to install a new bottom section and then re-install the pole.

Winchman

I install these poles for my day job. The engineer is right, many times we will set the base section in concrete and then several days later set the top section on top of it. Usually, when the crane get off of it it is so tight that it is almost impossible to spin the top section for final adjustment. You had better have it right the first time. I have turned them, with great difficulty and with large tools.:D These have been in place for 6-10 years so I am sure that they are pretty well stuck together.

Darryl,

The bottom sections are damaged and for liability reasons not suitable for re-use. It kills me, but they are going to have to go to the scrapper.

Regards,

Tim

gmatov
07-12-2010, 12:29 AM
TMC,

Is the view of the Forum why you are saying that 20 ton is the max for Porta-Powers?

I used 50 ton jackheads daily in crane repair. I doubt that Enerpac has discontinued them, unless pu**ies have complained that they are too heavy. They damned well are, but sometimes you gotta use them, and sometimes they are not enough.

Hell, I even have a 50 ton bottle jack. They can be bought, too. Save the expense of an Enerpac pump, and useful where you can't get power.

Here is another example. When Westinghouse was still a going concern, 100 ton Enerpac jacks were used on each foot of turbogenerators to lift them to shim to align. ONE power source with valves to direct pressure to the jack that needed to lift. Units weighed 400 to 500 tons.

Cheers,

George

Are you involved with the company whose poles are falling down all over the country? I should imagine you are looking for an inexpensive remedy to this problem. I don't think anybody has been injured, yet, but, if I read it correctly, you have hundreds of those pylons, if not thousands, out there. I do not wonder that you are looking to do what you want at the least cost possible. You are in for a world of hurt, money wise.

Ken_Shea
07-12-2010, 12:55 AM
Tim,
Steve has the answer clear up in post#4, a sure and quick way, why are you not considering that?

Ken

metalmagpie
07-12-2010, 11:42 AM
I am thinking this is going to need more force than you're thinking. Forget portapowers. If I had to do that I'd weld blocks top and bottom both sides drilled for heavy clevis pins, and install 6" hydraulic cylinders on both sides for even push. Pin them at one end and just let them push on the other, so it doesn't bend the ram when the pieces come apart. Plumb them both to the same pump with 10000 psi hydraulic line.

Heat the outer pipe with a rosebud or two or three or four, and turn on the hydraulic pump. When the pieces are separated, scarf off the blocks if desired.

tmc_31
07-12-2010, 02:00 PM
Tim,
Steve has the answer clear up in post#4, a sure and quick way, why are you not considering that?

Ken

Ken,

I have considered Steve suggestion, in fact cutting off the base near the joint then and slitting it for the inside is plan B. These poles have numerous penetrations so that it would be difficult to seal up and pump it apart hydraulically. Although I had considered that too.

Metalmagpie,

I have to do this with stuff that can be moved easily around the job site. Also welding to the top section will ruin the galvanizing and so is out. I am working out some push blocks that I can clamp to the poles (the machining part of this thread).

gmatov,

I realize that 40 tons may not be enough and that I can get larger jacks. I may do that. I am thinking two 50 ton air/hydraulic jacks (100 tons total). Do you know if these will work in the horizontal position. I have a 20 ton A/H I will have to try it horizontal. Yes, I am gearing up to repair these poles.

All,

Anyone have an idea how to calculate the force required? Sir John? Evan? Anyone?

Thanks,

Tim

gmatov
07-13-2010, 01:21 AM
tmc,

The jack head will work in any position. The pump won't but that is irrelevant.

The moment I read the above about welding to both pieces, I said that's a no-no, he is trying to salvage the major part of the installation, and they are galvanized.

Whether you can get bigger than 20 ton jack heads, see here:

http://www.enerpac.com/en-US/products/cylinders-lifting-products-and-systems/high-tonnage-0

50 to 1,000 ton, although 1,000 ton seems like it is on the large side.

Since you want to save the major portion of these stanchions, and they are made in a taper, are they not, it may be difficult to make push blocks that will grip the upper portion. It is tapered the wrong way. If you have a lip on the bottom edge to catch the joint of the upper section, it could work.

I assume your crimp roll makes them all to a close pattern?

Weld as you will to the bottom, throw away section, position 2 or 4 jack heads and go to town. You might need a couple 20 pound sledges on the lower section, or biggish soft faced mauls on the upper, to be saved. You don't want to mess up the galvanize, or you will be back in a couple years.

I know you can't say for litigation's sake what the problem is. Bad galvanize, lack of a weep hole, even bad steel. Usually, as far as I can see, such stanchions have a thick plate for a base, which should have a large hole in the base plate, so water buildup should not cause rust out. 4 all thread adjusting screws to plumb.

Ah, well, hope I have helped you a bit.

Cheers,

George

tmc_31
07-13-2010, 01:58 AM
George,

Thanks for the link to enerpac, seems they have a little better selection than porto-power. You are correct, there is a lip that I think I can catch on the top section at the slip joint The top set of blocks will be strapped to the top section. I will probably bolt the push blocks to the bottom section of the pole since it is to be discarded anyway. An earlier poster suggested using a demolition hammer (jack hammer) to jar the poles apart while another suggested using a pressure washer to force soapy water into the joint. These are only two of several ideas that have merit that have surfaced on this thread.

The company that designed, built and sold the poles "Whitco" is no longer around. They went bankrupt in 2006 and none of the owners can be found. Of course this leaves the pole owners holding the bag. I (fortunately) have not ever had any association with Whitco. I am developing a fix because I think there is a market for it, I am familiar with the problem and I think I have a relatively economical solution.


Many thanks to all who have made suggestions, even the explosive ones!:D


Tim

RancherBill
07-13-2010, 10:15 AM
Here's another "random far fetched solution"

I was driving yesterday and took a 'new look' at the poles I'd seen for years. They are BIG!

So here's two ideas. The first is a recycling of an earlier section. Heat the outer pipe with 4 tiger torches, when it is warm start pressure washing the inside to the pipe with cold water. Have some tension on the damaged section with the porta power.

My second idea which I call the pipealator might work. Essentially it's a U shaped device with guide wheels on the out side. On the inside there are guide wheels and an angle grinder. It would be a simple way to slit the inner pipe.
http://i294.photobucket.com/albums/mm100/rancherbill/pipealator.jpg

Edit - I'd only 90% of the way through the inner pipe to avoid damaging the salvageable outer/top pipe.
The inner pipe is under compression and the outer is under tension. The cuts reduce the compression.

gmatov
07-13-2010, 11:47 PM
Bill,

One of the problems with heating is that they are galvanized, danger of burning the zinc off, then where are you?I don't know if they are galvanize or galvalume, regardless, they won't take too much localized heat to destroy the protective/sacrificial layer.

If I am correct, tmc is trying to salvage all them stanchions that have from 8 to 24 BIG high wattage lamps illuminating college, high school and other arenas.

Several have already fallen over, and, fortunately, I don't think there have been any injuries.

I have no idea the cost of each, probably in excess of 50 thou. Stadiums, at least at my little high school field, usually have 6 or more of them. It is a big expense to replace them. If he can salvage them for a fraction of that cost, he has a good thing going.

Base section is probably 1 or 2 thou, installed. If there is no recourse to the mfg., venues are going to jump at any viable alternative.

I assume tmc is going to hook on and pull the top 90% of the stanchion off the base section, with a little force from hydraulics, not pull it off and lay it down and try to pull it apart.

At least, I wouldn't try it that way. Laying it down will put extra strain on the join, make it that much harder to get apart. Also, putting a strain on it with a crane will get that SOB flying around if you take too much when it parts. You don't want a 100 foot pole flaying about.

I am assuming that these things are straight taper, not necked down at the join, ie, no limit as to how far down they CAN go, without a shoulder to butt up to?

Good luck. I don't think you should have TOO much difficulty. Hope you make a few bucks while you save some school districts a few bucks. I don't know if the cost is covered under the school district's insurance against shoddy workmanship. I'd guess NO.

Cheers,

George

tmc_31
07-14-2010, 12:39 AM
Bill,

I like the pipealator:). For a while I considered such a rig only with a spindle turning an endmill to split the pipe section. I dismissed my idea as too complicated for work in the field. Yours however seems much simpler. In an earlier post doctordemo suggested slitting the pole section and arcane suggesting using a metal cutting saw blade in a skillsaw. George is right, I am afraid that applying heat via torches or rosebuds may damage the galvanized coating on the pole. This said, the redneck in me briefly considered wrapping a many coils of welding lead around the joint then attaching it to a big a$$ welder. Induction heating anyone:D ?

George,

The joint on most of these poles is at about 40% of the length. I need to lay them down prior to separating to avoid having the guys try to work with all this gear on an unstable pole in the air. Safety is the primary issue. I have separated them with the pole standing (read post #5, on this one the joint was 3' above grade) but it is a dicey situation.

All the best,

Tim

darryl
07-14-2010, 01:48 AM
Another idea- I'll try to describe it- use the concept of leverage and compression. Say you have a triangle made of steel beams or whatnot- the connection points are hinged. Lay the long side of the triangle on the ground, and make the length of the long side such that it's only a little shorter than both other sides put together. This means this will be a long triangle, but with very little height. Now if you pushed downwards on the top of the triangle, the base will be stretched while the two other sides are put in compression. Arrange the two shorter sides to be only a tad longer than the base section, and you get an enormous mechanical advantage if you apply force perpendicular to the base.

Transfer this concept to the pole you're dealing with. Make two assemblies, each consisting of two steel tubing segments about ten feet long, and hinged together. Gonna be some welding needing done here. Lay one assembly on top of the horizontal pole, then lift the hinge area off the pole by maybe a foot or so. Pin the other ends to the pole where they touch it. Turn the pole over and attach the second assembly the same way. Now just figure out how to pull the hinged ends towards the pole. What comes to mind is something like a log splitter which sits under the pole, and can pinch from both sides simultaneously. For every thousand pounds applied there, many times that force will be trying to force the pole sections apart.

I didn't do a very good job of explaining this idea, but I don't think it's hard to grasp. You'd probably set it all up on supports so it doesn't have to be held while pinning the ends. Whatever mechanism that would be used to bring the hinged junctions on the steel tubing segments towards each other can likely be used to support those elbows as well, and the whole setup would be in the same horizontal plane. Oh, yeah, I guess I've stuck on the idea of drilling holes in the pole sections so pins can be inserted to have something to press against. If there's any other way to clamp something firmly enough to the pole without drilling it that can be pushed against without slipping, then use that instead of drilling and pinning.

A.K. Boomer
07-14-2010, 08:55 AM
The way I see it is you only really have one shot at saving both sections,

You can't use internal pressure to separate --- it will just expand the inner pipe against the outer.

You also cant build an apparatus to attach to the ends to try and separate --- This is a classic "knee-jerk" reaction and it's totally flawed by an engineering viewpoint as what will happen is the narrow outer section will be the one that ever so slightly "gets stretched" -- what this effectively does is act like a Chinese finger torture deal where the harder you pull the more it will grip...

This is a fiasco for sure, there's nothing more stubborn than a mild taper fit,

Your only real hope is to attach something like a large collar to the base unit real close to the joint ------ then make a floating collar that butts up against the base of the top unit and catches its thickness, the two collars are then fitted with massive push bolts all around them, by prying in this direction you both expand the base of the outer top pipe's diameter whilst pushing against it, yet the inner bottom pipe is actually being stretched so its diameter shrinks,

Torque bolts uniform , then start creating shock wave's around the outer casing with a little hand sledge --- start at the base and work your way up, re torque ---- repeat.

The answer for separation does not lie in pulling the two units apart, Pushing the two units apart is your surest bet,,, Although a highly elastic example ---- A simple stubborn radiator hose will prove this theory time and time again...

Boucher
07-14-2010, 10:23 AM
There are inflatable packers that are used to isolate sections of bore hole in fracking operations in the water well and oil well business. something like this would allow you to pump them apart. These are basically rubber bags that are inflated to grab the wall of the bore hole. The normal taper of the top section could be used to to hold an internal plug over however long an area need to prevent dammage. The bottom section if it is not needed could be cut and cross bolts installed to hold a seal in the bottom section. We used inflatable packers to pump liquid CO2 into rock bore holes. You might even try just running some of that on the internal bottom section. Then like the gunpowder idea maby run some liquid nitrogen on it and hit it with a hammer.

RancherBill
07-14-2010, 04:16 PM
Pipealator Deaux

You are right on the metal cutting saw. A grinder would wear out too quickly.

This is a thought I had on a simple mechanism. The previous u-shaped device might be hard to control because of it's size.

This is on a sled. Springs keep the cutter where it should be. You can propel it by pushing with a stick or pulling with a rope. one thing that isn't shown if the release mechanism. You have to have a release mechanism for the springs to get it in or out of the pipe and in emergencies/failures.

http://i294.photobucket.com/albums/mm100/rancherbill/pipealatordeaux.jpg

The saw should actually be 1", to pick a number, ahead of the trolley. You can cut all the way through the pipe before the wheels fall over the edge of the inner pipe and thus let the saw go too deep.:eek: :eek: :eek:

ulav8r
07-14-2010, 05:50 PM
Can you remove all the cross arms? If so lay it on rollers so you can rotate the assembly. Support the top section so it stays straight but support the bottom slightly out of line. As you rotate the assembly the taper should work itself apart.

darryl
07-14-2010, 09:49 PM
It just came to me- use my idea but do it on the inside of the pole. A single hydraulic cylinder can be used to press outwards on what I called the 'elbows'- the hinge pin points. It all hinges (sic) on how you provide points for the arms to push against on the upper and lower sections of the pole.

Next thing that comes to mind relates to the first idea- putting the leveraging arms on the outside as I suggested a couple of posts ago. If the upper section slips over the bottom section, then maybe there's a lip accessible for two of the arms to push against. If so you only need holes in the lower section.

tmc_31
07-14-2010, 09:53 PM
Hi guys,

More interesting ideas, awesome.

darryl,

This is an interesting idea, and may be inexpensive to build (more stuff to build in my little machine shop:D ) If I understand you correctly it would be kind if like a scissor jack split in half top to bottom. Anchor the lower arm of both sides to the bottom section with thru bolts, let the top arm push against lip of the top section. Insert large bolt through the pole and the center hinge of the arms and tighten with an air gun. This may work and would be cheaper than buying porta powers. What you are describing with 10' arms would be pretty hard to handle in the field. However, 2' arms might be doable. How much force you could generate with this apparatus? A lot I would guess.

Boomer,

I think you are right, pushing the poles apart should be easier than pulling them. I really hadn't thought of the Chinese handcuff analogy, but it is a good description of what will happen if you try to pull these poles apart.

Boucher,

I hadn't heard of this technology. If you could seal up the pole sections as you describe and could apply 2000 psi with a hand pump or air over hydraulic pump you could generate over 300 tons of force pushing the poles apart (alright guys, be ready to run). One difficulty may be sealing up the pole joint. The other thing is you would need to be able to remove the plug in the top section as that is the wireway. Neat technology!! Do you know of a vendor?

Rancherbill,

Neat carriage! I like the springs to keep down force on the saw blade in the tapered pipe. Maybe three sets of guide wheels one set at the rear, one set just behind the blade and one set just in front of the saw blade.

ulav8t,

I can remove the crossarms if necessary, but would rather not as it creates additional work. I need to be able to retrofit 4 poles in two days, so speed is essential.

Last night, I had a brain fart about creating an induction heating system based on an engine welder and some coils of welding lead. Just for grins I searched on induction heating and found the millerwelds site. They have developed just such a system for use in pre and post heating welds on large pipe. It consists of a 5-25kW power source and wire coils in an insulating blanket. The system will heat the pipes from 400deg F to 1250deg F.

All the best,

Tim

RancherBill
07-14-2010, 10:16 PM
Tim

Steal all the best and just go do it!!!!

You will be rich with TMC_31 Pole Salvage Service Inc. There are a lot of good tops going for salvage.

darryl
07-14-2010, 11:34 PM
Tim, I suggested 10 ft arms because the distance they would push when 'scissored' would be greater than with shorter arms. But maybe 10 ft is too long.

I just did a quick mock-up using 42 inch long arms, which are some scrap plywood pieces I have laying around. Looks to me like I'd get about one inch of push from a 6 inch range of motion at the pivot. If I raised the pivot to about 10 inches, there would be about 2 inches of push, but the mechanical advantage is less- 5-1 vs 6-1. It looks like I'm getting about 5 or so degrees of angle on the arms when the pivot point is up, and my feeling is that that is about all the angle you would want to start with. The best mechanical advantage is when that angle is close to 0, but then the distance that it can push is much less.

What you need is the hardest push right from the start, so (I'm guessing again) I think you would not want to use arms shorter than about 5 ft each. If you managed to make this apparatus and got your pole sections started coming apart, you may have to reposition the arms at least once, maybe twice- or find a way to use shims as the separation process proceeds. Or make use of some large diameter threaded rod as a way to alter the length of two of the arms. Whatever you do, the high pressure push needs to be inline with the arms, so no bracketry or whatever that would impart any bending moment to the arms.

I was thinking about this problem earlier today and came up with the idea to set up the apparatus on a cradle that you would build, which keeps all the parts of it more or less together, then you lower the pole onto the cradle as well (in the proper position to be worked on of course). The cradle might be a framework that you weld up and put wheels on so it can be maneuvered into position for use, or put away when not in use. Far as that goes, you could build it from 2x4s- basically it's just a replacement for a few sawhorses. It doesn't figure in the process of applying pressure, it just supports the hardware

tmc_31
07-15-2010, 12:07 AM
darryl,

yes, I can see the mechanical advantage improves as the arms move closer to the pole. The joint should have to only slip about 2-3 inches for the seal to break. I think I would use some spacer blocks with this apparatus as the pole sections moved apart. A fella might have to run it in and out several times to get the required travel. You would almost certainly need a cradle or saw horses or something to support the arms while attaching them to the pole.

Thanks for the idea,

Tim