Direct Drains - Glossary


	Clock References
	Clock references are given clockwise, ie. from 10 o'clock to 2 o’clock=1002. Thus the upper half of a pipe is 0903 and the lower halt is 0309. This is illustrated below :



	Collapsed
	Complete loss of structural integrity. Most of cross-sectional area lost.



	Connection
	A lateral pipe which has been added to the sewer. lncludes all saddle connections



	Continuous Defect
	A defect which extends or is repeated over two or more consecutive pipe lengths.



	Debris
	Grease, organic or silty materials deposited in a sewer, which cause flow turbulence and a reduction in hydraulic efficiency. Examples of this are road grit, fatty deposits and soil washed in by infiltarting groundwater.



	Defective Connection
	The junction or the adjacent sewer have become damaged during or after construction, or the connection is incorrectly positioned or of poor workmanship.



	Defective Junction
	The junction or the adjacent sewer have become damaged during or after construction.



	Definitions of Structural Defects
	The following definitions are given to assist the classification of defects. CRACKED Crack lines visible on the pipe wall, pieces all still in place. FRACTURED Cracks visibly open on the pipe wall, pieces all still in place. BROKEN Pipe cracked with pieces of pipe visibly displaced, some pieces could be missing. Cracked, fractured and broken can be further described as; LONGITUDINAL Defect runs approximately along the axis of the sewer. CIRCUMFERENTIAL Defect runs approximately at right angles to axis of the sewer. MULTIPLE Combination of both longitudinal and circumferential defects.



	Deformed
	Original cross-section of sewer altered, pipe probably extensively broken.



	Displaced Joint
	The spigot of the pipe is not concentric with the socket of the adjacent pipe.



	Encrustation
	Deposits left by the partial evaporation of infiltration by groundwater containing dissolved salts. Classified into light, medium or heavy by percentage diameter lost.



	Infiltration
	The ingress of groundwater into the sewer through defects, joints or manholes. The four terms used to describe this are : SEEPER The slow ingress of water. The usual indication of this type of infiltartion is that the joint or crack 'glistens' in the light of the CCTV cameras. DRIPPER Water dripping in through a crack or faulty joint. RUNNER Water running through a crack or faulty joint. GUSHER Water entering a pipe under pressure through a crack or joint



	Intruding Connection
	The connection intrudes into the sewer



	Junction
	A purpose made or preformed junction built into the sewer during construction.



	Line
	A visible divergence in the sewer line. May be left, right, up or down.



	Manhole
	Any access point. may be direct or side entrance shaft, or lamphole. May be 'buried' , i.e. covered over at same time since construction.



	Obstruction
	Solid material in a sewer which impedes the inspection and /or causes a reduction in hydraulic efficiency. e.g. brick, rods, or displaced sealing rings.



	Open Joint
	Adjacent pipes are longitudinally displaced at the joint.



	Roots
	The ingress of roots through defects in the sewer,connections of manholes. Described as fine, mass or tap roots depending on severity. 'Tap' means that individual roots are over 10mm thick.



	Scale
	Hard deposits which cannot be identified as encrustation. e.g. deposits resulting from corrosion of iron pipes, or hardened ground.



	Water Level
	The level of water at the observed point in the sewer.