| Term |
Definition |
|
| Gallons per minute |
US customary unit to measure liquid volume discharge rate. One gallon per minute equals 0.063 liters per second. (abbrev. GPM). |
| Galvanic cell |
A cell consisting of two dissimilar metals in contact with each other and with a common electrolyte (sometimes refers to two similar metals in contact with each other but with dissimilar electrolytes; differences can be small and more specifically de |
| Galvanizing (spelter coating) |
A plating for iron and steel composing primarily of zinc. It may be applied electronically or by dipping the pipe or casing in molten zinc (the fumes are poisonous to breathe). |
| General corrosion |
Corrosion in a uniform manner. |
| Geographical Information System (GIS) |
A computer software system designed to store,manipulate, analyze, and print geographically referenced information. |
| Gloves |
Gloves (cloth, rubber & leather) used by operators, crew members and tracking locator operators that provide maximum protection against electrical shock if properly used. |
| Gradation |
Sieve analysis of aggregates. |
| Grade |
The elevations shown on plans and/or survey grade stakes for the installation of the carrier pipe. It is occasionally to give elevations for casing. In most cases, it is given to the flow line but can also be given to the top of the pipe or casing. |
| Gradient |
See Grade. |
| Grain |
A portion of a solid metal (usually a fraction of an inch in size) in which the atoms are arranged in an orderly pattern. The irregular junction of two adjacent grains is known as a grain boundary; also a unit of weight, 1/7000th of a pound; also use |
| Granular |
Technical term referring to (the uniform size on grains of crystals in rock. |
| Graphitization (graphitic corrosion) |
Corrosion of gray cast iron in which the metallic constituents are converted to corrosion products, leaving the graphite flakes intact, Graphitization is also used in a metallurgical sense to mean the decomposition of iron carbide to form iron and gr |
| Gravity sewer |
A sewer that is designed to operate under open channel conditions (below pipe full capacity) up to a maximum design flow at which point it will become surcharged. |
| GRC |
Glass fiber Reinforced Concrete; a rehabilitation lining. |
| Grease trap |
Mechanism in a lateral that collects grease before it can reach a main line. |
| Grinder pump |
See Sewage grinder pump |
| Grip |
Applies travel to rod or pipe. |
| Ground mat |
Metal mats rolled out on either side of drill rack for operators and crew to stand on during operation to give grounding protection in case of electrical strike. |
| Ground mat cables |
Cables connecting the drill rack to the ground mats. |
| Ground plane |
The surface upon which the machine is placed. |
| Ground rod |
This is a copper/brass rod which is hand driven into the ground and is connected to the drill rack and mats to provide adequate grounding of unit and personnel. |
| Ground rod cable |
Cable connecting the mats and drill rig to the ground rod. |
| Ground water table (or level) |
Upper surface of the zone of saturation in permeable rock or soil (when the upper surface is confined by impermeable rock, the water table is absent). |
| Groundwater table |
See reference groundwater level. |
| Grout |
(1) Material used to seal pipeline and manhole cracks; also used to seal connections within sewer structures. (2) A material, usually cement based, used to fill the annulus between the existing pipe and the lining; and also to fill voids outside the |
| Grouting |
(1) Filling of the annular space between the Host pipe and the Carrier Pipe. Grouting is also used to fill the space around laterals and between the new pipe and manholes. Other uses of grouting are for localized repairs of defective pipes and ground |
| GRP |
Glass Reinforced Plastic, a family of rehabilitation linings. Often generically known as Reinforced Plastic Mortar (RPM) and Reinforced Thermosetting Resin (RTR). |
| Guard |
A protective device fitted to the machine to minimize the possibility of inadvertent contact with hazards. |
| Guidance system |
The guidance system continuously confirms the position of the MBTM. |
| Guide rail |
Device used to support or guide, first the shield and then the pipe within the drive shaft during a pipe jacking operation. |
| Guided auger boring |
A term applied to auger boring systems which are similar to microtunneling, but with the guidance mechanism actuator sited in the drive Shaft (e.g. a hydraulic wrench which turns a steel casing with an asymmetric face at the cutting head). The term m |
| Guided boring |
Method for the installation of pipes, conduits and cables using a surface-launched drilling rig. A pilot bore is drilled using a rotating drill string and is then enlarged by a back reamer to the size required for the product pipe. The necessary devi |
| Guided drilling |
See Guided Boring. |
| Gunite |
A rehabilitation technique that employs steel reinforcement fixed to the existing sewer which is covered in concrete, usually spray applied. |
| Gusher |
Applied to infiltration to quantify water flowing under pressure into a sewer in a continuous way through a defect or faulty joint. |
| GWI |
Groundwater Infiltration; results from the movement of groundwater in the saturated zone into the collection system through defects in the components of the system located below the water table. |
