All pipe is to be supplied with nothing in the hole so that water, steam, or other stuff can be put in the pipe at a later date. All pipe is to be supplied without rust as this can be more readily supplied at the job-site. All pipe is to be cleaned free of any covering such as mud, tar, barnacles, or any form of manure before putting up, otherwise it will make lumps under the paint. Pipe over two miles long must also have these words painted in the middle so the fitter will not have to walk the full length of the pipe to determine if it's long pipe. All pipe closures are to be open at one end.
All pipe fittings are to be made of the same stuff as the pipe.
No fittings are to be put on pipe unless specified. If you do so, straight pipe will become crooked pipe. Fittings come in all sorts of sizes and shapes. Be sure to specify the direction you are going when ordering. Flanges must have holes for bolts separated from the big hole in the middle.