The taper rate for all NPT threads is 1â16 (3â4 inch per foot) measured by the change of diameter (of the pipe thread) over distance. The angle between the taper and the center axis of the pipe is 1Â° 47'â² 24â³ (1.7899Â°). Commonly-used sizes are 1/â8, 1/â4, 3/â8, 1â/2, 3â/4, 1, 1 1â/4, 1 1â/2, and 2 inch, appearing on pipes and fittings by most U.S. suppliers.
Schematic representation of the photochemical ozone formation and destruction. Ozone is a gas found in the atmosphere consisting of three oxygen atoms: O 3. Ozone is formed in the atmosphere when energetic ultraviolet (UV) radiation dissociates molecules of oxygen, O 2, into separate oxygen atoms. Free oxygen atoms can recombine to form oxygen molecules but if a free oxygen atom collides with an oxygen molecule, it joins up, forming ozone.
The ozone molecules in the upper atmosphere (stratosphere) and the lower atmosphere (troposphere) are chemically identical, because they all consist of three oxygen atoms and have the chemical formula O3.his region of the atmosphere is called the stratosphere. The ozone in this region is commonly known as the ozone layer. The remaining ozone is in the lower region of the atmosphere, which is commonly called the troposphere. The figure (above) shows an example of how ozone is distributed in the atmosphere.