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 hole in the ozone layer happens because the ozone in the stratosphere is destroyed by chlorine and bromine from halogen atoms. These atoms come from man-made halocarbon refrigerator gases (chlorofluorocarbons [CFCs], freons and halons) which are emitted at ground level but move up into the ozone layer.zone depletion was observed to increase as emissions of halo-carbons increased. Ozone is a protective layer in the upper atmosphere. It is formed when oxygen molecules absorb short wavelength ultra violet radiations from the sun. Ozone is mostly destroyed by free radicals in the atmosphere.