(1) All piping, including tubing,
fittings, gaskets, and packing, shall be made of material suitable for use with
nitrogen fertilizer solutions and designed for the maximum
pressure to which they may be subjected.
(2) Screwed joints are permissible provided they are able to withstand
maximum pressures to which they are
subjected. Pipe joint compounds shall be resistant to
nitrogen fertilizer solutions and compatible with materials employed.
(3) Provision shall be made in the piping system to compensate for
expansion, contractions, jarring, vibration and settling.
(4) After assembly, all piping and tubing shall be tested and proved to be
free from leaks at a pressure not less than the normal operating pressure of