24 foot 3 1/2" Structural Steel Pipe, good for 10' Dish?

[SERAPIO]

My local craigslist has the following mast

3 1/2 Structural Steel Pipe


Looks to be a base plate 2' x 2' mount, How safe can this be for a 10FT Unimesh / Sami / Perfect 10 dish??

 

[Arion]

The piping looks thick but my 10' dish takes a 4 1/2 inch pipe. Can't imagine a 10' dish with a pipe that narrow. At the least you would probably have to fabricate a reducing collar.

 

[SERAPIO]

an other factor would be mounting the actual dish 24 feet above the ground. More $$$ to get a Crain or cherry picker

 

[harshness]

an other factor would be mounting the actual dish 24 feet above the ground.

That's what band saws and cutting torches are for. You can make an arbitrarily long section of pipe (usually 21') into a much shorter piece.

 

[SERAPIO]

That's what band saws and cutting torches are for. You can make an arbitrarily long section of pipe (usually 21') into a much shorter piece.

True but then it would be cheaper buying a shorter pole too

 

[harshness]

True but then it would be cheaper buying a shorter pole too

I just looked up a 10' chunk of 3.5" standard (schedule 40) pipe online and it was almost $200. Sometimes it pays to cut down a longer piece if you can figure out how to move it (and you're willing to live with the pitting and rust).

 

[BigRyan]

I saw a reducing collar fabricated out of PVC, more like a bushing that took up the slack. Another member did something like this, I thought was neat.
https://www.satelliteguys.us/xen/attachments/img_0099-1-jpg.80919/

 

[harshness]

I'm not sure I'd pick PVC over steel pipe. Sure, the surface is nice and smooth, but I wonder if it has the grab and torsional strength necessary to prevent twisting. PVC has all the right properties for pressure pipe, but the structural properties surely aren't the same as steel.

 

[richyrich]

This pipe new, without welding is 9.00 or more a foot 9x9= eighty-one dollars; yes; materials a worth more new.;; and cost less old; and steel @ 3.0 id sched. 40 holds the big dish down, and they listed the types found all over the US from the 80's to the 90's...

 

[harshness]

There's technically no such beastie as 3" ID pipe. There's just 3" size pipe. 3" schedule 40 pipe is nominally 3.068" ID (although with modern tolerances it is probably bigger as the "thickness" of everything runs within a few thousandths of the absolute minimum).

Up to 12", pipe sizes are not based on actual dimensions but the one dimension that always stays the same is the OD so regardless of schedule, 3" pipe will always have a 3.5" OD. 3" XXH pipe has a nominal ID of 1.8" and an OD of 3.5".

The confusing part is that at >=14", pipe size is the outside diameter.