Discussions with other surveyors has caused me to think a 3/4" plumbing pipe should be called a 1" o.d. pipe.(outside diameter). But then I think that sounds clumsy and not what has been historical. thoughts or standards?
ID
> Discussions with other surveyors has caused me to think a 3/4" plumbing pipe should be called a 1" o.d. pipe.(outside diameter). But then I think that sounds clumsy and not what has been historical. thoughts or standards?
Common usage, prior to plastic caps, in my area were "crimp top" pipes that were listed as xx" O.D. crimp top in descriptions. Outside diameter was cited because the inside diameter of these could not be directly measured once the pipe was set.
These were 1/2", 3/4" or 1" inside diameter pipes with one end crimped closed in a vise. The open end was driven into the ground and the crimped end prevented the top from mushrooming as it was driven. The resulting narrow flat strip was often center punched at the correct distance and line.
Not monuments, but in chemical plant work, it's I.D. plus schedule type: 20, 40, 80, etc., depending on pressure being used. You're not going to find many places that can "pinch" a schedule 40 pipe.
It's always the INSIDE, unless specified otherwise.
Same for witness trees. MIDDLE of where stump hole would be, if it died, that was all that was left.
But, I find MANY that were meas to FACE of tree, AT THE BLAZE.
But, middle is the standard.
N
> Not monuments, but in chemical plant work, it's I.D. plus schedule type: 20, 40, 80, etc., depending on pressure being used. You're not going to find many places that can "pinch" a schedule 40 pipe.
When you have a steel supplier like Sebulskys Steel less than a mile from the county courthouse it would not be a problem. They received, fabricated and shipped by the truck load. Still they would cut 5 or 6 5/8" rebar to 30" lengths in minutes at minimum charge.
http://en.wikipedia.org/wiki/Nominal_Pipe_Size
We use Inside diameter for 12" and under, Outside diameter anything larger. Usually called out in our Engineering plans.
For the person reading your plat or map and attempting to relocate the monument, it would help assure proper monument identification if the dimension provided included whether it was "nominal pipe size," "inside diameter," or "outside diameter." If, for example, it is stated on a plat as "1-inch pipe," how does the reader know whether it is nominal size, outside diameter or inside diameter unless it is so stated? Including other information such as 3 inches above grade, flush, iron, copper or bent easterly, would also assist one attempting to identify the monument. Provide sufficient information, it does not have to be a book, for the potential user of the map to identify the monument you placed or found. Sometimes a sketch is necessary also.
I'm thinking now that "pipe" says inside diameter. "pin" or "rod" implies outside diameter. 3/4" pipe without specifying diameter reference is definately inside diameter and you would be suprised to find a 1/2" plumbing pipe.
Typically unstated is ID.
If I am noting OD then I say so on the map.
> Typically unstated is ID.
>
> If I am noting OD then I say so on the map.
Yes, steel or iron pipe is sold by the inside diameter and that's the logical way to describe it unless otherwise stated. It's certainly the convention I use.
> Yes, steel or iron pipe is sold by the inside diameter
Technically it's a nominal size. For example, the ANSI inside diameter specification for 3/4" Schedule 40 steel pipe is 0.82 inch.
> > Yes, steel or iron pipe is sold by the inside diameter
>
> Technically it's a nominal size. For example, the ANSI inside diameter specification for 3/4" Schedule 40 steel pipe is 0.82 inch.
Yes, but for identification purposes, one need typically only determine whether the nominal inside diameter is 3/8" (rare in Central Texas), 1/2" (very common here), 3/4" (very common here), 1" (less common here), 1-1/2", or 2" (mostly found on rural tracts around here). And if you find what you identify as a 24" x 1/2" galvanized steel pipe and go to the plumbing supply house and ask for a 24" length of 1/2" galvanized steel pipe, what you should expect to receive will be essentially identical. That's why the description works.
Try going to a plumbing supply house, ordering a piece of 0.62" galvanized iron pipe, and seeing whether there is any recognition at all that you've asked for nominal 1/2" pipe.
>
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> Try going to a plumbing supply house and ordering a piece of 0.62" galvanized iron pipe and see if they even take you seriously.
Or go to the local deli, and ask for 1.5 L-B-S (Say the letters L-BEE-S's) of shaved turkey, and just look at them. Lost as could be!
🙂
N
> These were 1/2", 3/4" or 1" inside diameter pipes with one end crimped closed in a vise. The open end was driven into the ground and the crimped end prevented the top from mushrooming as it was driven.
Crimp-tops aren't something I've ever run across in my area, but I wonder if the reason they exist has more to do with being cut by a shear than to prevent mushrooming. A shear would be a lot faster than using a pipe cutter or a saw.
close enough
A pint's 1.04 Pounds the world around
> > These were 1/2", 3/4" or 1" inside diameter pipes with one end crimped closed in a vise. The open end was driven into the ground and the crimped end prevented the top from mushrooming as it was driven.
>
> Crimp-tops aren't something I've ever run across in my area, but I wonder if the reason they exist has more to do with being cut by a shear than to prevent mushrooming. A shear would be a lot faster than using a pipe cutter or a saw.
Jim,
I would agree a shear might be quicker. However, several of the metal suppliers where crimp tops were common, including the one I mentioned before, used industrial band saws with feed tables and length stops. 
Set the length, load three twenty foot long rebars or pipes. The drop the saw, advance the feed. Repeat seven times and you have twenty-one 30 inch pipes/rebars.
Never saw the crimp tops made but the same shops had hydraulic presses and metal forming machines. All these shops fabricated metal framework and parts for factories and mineral processing facilities. They made pipes with flattened ends and bolt/pin holes for scaffolding and other prefab frameworks.
Pinchtop
I agree with all the insiders. When you go buy it, it's always I.D.
Jim Frame is right in our part of the country, that a shear usually perfected the pinchtop, but some were done in the field with an ax and a little wiggling back and forth. Of course this was usually welded water pipe which is an entirely different animal than schedule 40 pipe. It also costs about half as much, and lasts about as long. Wonder when reinforcing bar will talked about this way.
Pinchtop
It's ID; try to go to a pipe yard and buy pipe by OD.
Many times, they cut the pipe in the field. It is faster to do it with a chisel and 4lb hammer, bend it and wala! - done.
Hack saw blades were crappy and expensive in the "old days", and this was the preferred method; hence pinch pipes.
I love to find these things - they are always old.
I use a power hack saw, BTW. I have cut up an entire bridge full of rebar with it and it's still going.
The gist of the discussion seems to be that only those who buy pipes and set them as monuments should be allowed to read a plat. Heaven forbid the homeowner actually use the plat she paid so dearly for to help decide where to put her garden.
