Also called bell and spigot piping this gravity-rated vent and drain or pressure piping, has a bell-shaped section at one end with a straight section at the other. The straight part fits into the bell-shaped end as pipe is being installed.
Method of cutting down large trees, which makes use of the way the tree leans naturally. A horizontal face cut goes about a quarter of the way through the trunk, with an upward angled cut just below, intersecting the face cut, making the tree becomes unbalanced when this piece of wood is removed. Another horizontal cut is made on the opposite side of the trunk slightly higher than the face cut. When a wedge is inserted into the back cut, the tree falls forward because it goes past its center of gravity.
Measurement of long-term hoop stress, which is the item's resistance to pressure from the inside, rating of plastic pipe, at a specified temperature in pounds per square inch. The force is exerted outward on an article, which has a circular cross section, like a pipe.
Test using noncompressible liquid under pressure. Test pressure is equal to or greater than the maximum operating pressure that will be utilized when in use, depending on specifications of requirements. Codes often require that a hydrostatic test be done at 1 ½ times the normal operating pressure of the particular system, to guarantee that the system is leak-tight and safe. While some systems are only tested before the first operation, systems such as steam boilers are tested periodically to guarantee that no deterioration has occurred during use.