To understand what a slipped, or herniated, disc is, you have to understand how the intervertebral discs work in your spine. Intervertebral discs are natural shock absorbers between the stacked vertebrae. These discs have two main components, an outer fibro-elastic shell and an inner, gelatinous core.
Drain-waste-vent (DWV) pipes carry waste and water out of the house without gurgles or fumes. Never install or replace a DWV pipe without consulting a building inspector. These pipes must be installed according to precise specifications. Drainpipes. The centerpiece of a DWV system is the main stack, usually a pipe 3 or 4 inches in diameter that runs straight up through the roof. A secondary stack, perhaps 2 or 3 inches in diameter, serves a branch of the system.
To ensure that the water seal is maintained, the slope and size of the waste pipe connecting it to the stack pipe depends upon the length of the pipe run, typical figures are: Stack pipes should not be joined into less than 450mm above the bottom of the bend at the bottom on the stack pipe underground.