Pipe nipples and fittings typically have a series of letters and numbers stamped on them. what do they mean?
927858
Typically pipe and fittings have markings that indicate the material from which they are made and the specification to which they are made. To cover all of these with a chart is a pretty good task since this covers ASTM, ANSI, API, AWWA and other standards and specifications.\n\nThey may also have the manufacturers indentification or symbol. That is a completely different can of worms.
1072434
I'd used the pipe character (|). It's above the backslash.
1108275
A numerical digit, the physical shape of the number, what it symbolizes, how it is spelled, what abstract thought each brings to mind.
416889
Odd numbers and the number of letters in them.\n\n1 is 3\n3 is 5\n5 is 4\n7 is 5\n9 is 4\netc..
924835
A flat, denoted by a symbol that looks a bit like a lowercase "b."
164606
there are # embossed on a block surface. On a small block 8 they are on the front. A dealer will tell you what the code means
774116
the letter S... it stands for sulfur
41266
(_o_)   Do you know what these symbols mean?\n\n (_x_)\n  \n (_!_)
1063910
Flanges are flat plates attached to the ends of pipes and associated fittings such as valves, auto mufflers, etc. Their purpose is to provide an attachment surface for bolting two such fittings together. An ordinary flange has a hole to accommodate flow through the fitting; a blind flange has no hole and is used to close off a fitting with a mating flange. See the ref.
432679
There is a description of the symbols and their meaning at the US Mint website, here:\n\nhttp://www.usmint.gov/mint_programs/50sq_program/states/index.cfm?state=NY
727959
It's a string that has a metal weight on one end (a plumb bob). It is hung by the other end, and the weight pulls it down so it makes a vertical reference line. It's used in construction to see that walls and objects are vertical.
870803
This is a note or part number on a drawing with an arrow attached pointing to something on the drawing such as a bolt, nut or other standard part to define its characteristics without any other information.\n\nThe object is usually also listed in the 'bill of materials' above the title block on the drawing.
248113
They don't say what they are because you are suppose to get a copy of B31.9 and follow its requirements. \n\nB31.9 can change from time to time and this way the specification is always current. If the specification spelled out B31.9 and then quoted the requirements and they had changed in the mean time there would be a conflict.\n\nI have written many specifications for piping and this is the only way to be sure B31.9 or other industry standards are met.
4239
it has to do with estimating the steel weight (of a pipe)
766762
The class of a valve refers to ANSI flange ratings. They start with 150# class,and go up thru 400#, 600#, 900#, 1500# and 2500#\n\nThe actualy pressure rating varies with material and temperature.\n\nValves typically are manufactured to have a pressure rating to match the nominal flange rating.\n \nAs an example: a steel 150# ANSI flange has a pressure rating of about 285 psi at 100 degrees F and declines to about 20 psi at 1000 degs F.  NOTE: Carbon steel is not used above about 750 to 800 degs F for extended periods of time due to changes in the carbon structure that weakens the steel.
180692
perhaps roman numerals
1071137
That would be according to the mail client...Each uses a different symbol.