| Term |
Definition |
|
| Machine roller |
See cam follower. |
| Major blockage |
A blockage (structural defect, collapse, protruding service connection, debris) which prohibits manhole-to-manhole cleaning, TV inspections pipe flow, or rehabilitation procedures. |
| Male hex connector |
See shank. |
| Man-accessible |
Description of a pipe or excavation which can be physically entered by an operative. |
| Man-entry |
Describes any trenchless technology process which requires an operative to enter a pipe, duct or bore. OSHA has no minimum size limit for Man-Entry; however, they address a much broader concept of "confined space" in Title 29 Code of Federal Regulati |
| Manhole |
A structure that allows access to the sewer system. |
| Manning's Formula |
An equation for the value of coefficient c in the Chezy Formula, the factors of which are the hydraulic radius and a coefficient of roughness; an equation itself used to calculate flows in gravity channels and conduits. |
| Manual Inspection |
Method of sewer inspection that usually involves physical entry and hands-on examination; also includes used of CCTV camera with manual puppetting (e.g., in manholes). |
| Manual mechanical shield |
Open shield in which manpower is used to excavate the material but which has some steering capability. |
| Marsh funnel viscosity |
An instrument used to measure viscosity. For trenchless applications, used to determine slurry viscosity. |
| Master casing pusher |
See casing pusher. |
| Master track |
The rear most track section. |
| Maximum allowable operating pressure |
The highest working pressure expected and designed for during the service-life of the main. |
| Measurement while drilling (MWD) |
Borehole survey instrumentation that provides continuous information simultaneously with drilling operations, usually transmitting to a display at or near the drilling rig. |
| Mechanical cleaning |
Methods used to clean sewer lines of debris mechanically with devices such as rodding machines, bucket machines winch-pulled brushes, etc. |
| Mechanical props repair |
See Rerounding. |
| Median barrier |
A double-faced guardrail in the median or island dividing two adjacent roadways. |
| Melt flow |
A measure of the molten material's fluidity. |
| Melt flow rate |
The quantity of thermoplastic material in grams that flows through an orifice during a 10-minute time span under conditions as specified by ASTM D 1238. |
| Melt index |
The melt flow of a thermoplastic material as determined under Condition E of ASTM D 1238. Condition C or high load melt index produces a higher melt flow for a given material as a result of the greater force applied to the sample during the test. |
| Melt viscosity |
The resistance of the molten material to flow. |
| microtunnel boring machine (MTBM) |
The microtunnel boring machine (MBTM) refers to the microtunnel shield jacked through the earth which excavates the ground in advance of the pipe being installed. |
| Microtunneling |
A trenchless construction method for installing pipelines. Microtunneling uses all of the following features are utilized during construction: (1) Remote controlled - The microtunneling boring machine (MTBM) is operated from a control panel, normally |
| Midi-rig |
Steerable surface-launched equipment for the installation of pipes, conduits and cables. Applied to intermediate sized drilling rigs used as either a small directional drilling machine or a large guided boring machine. Tracking of the drill string ma |
| Million gallons per day (mgd) |
US customary unit for flow measurement. One MGD equals 43.81 liters per second. |
| Mini-horizontal directional drilling (Mini-HDD) |
A term sometimes applied to Guided Boring. |
| Mixed face |
A soil condition that presents two or more different types of material in the path of the bore. |
| Modifications |
(1) A written amendment of the contract documents signed by both parties. (2) A change order. (c) A written clarification or interpretation issued by the engineer in accordance with the terms of the contract. (d) A written order for a minor change or |
| Modified sliplining |
A range of techniques in which the liner is reduced in cross sectional diameter before insertion into the Carrier Pipe. It is subsequently restored to close to its original diameter, generally forming a close fit with the original pipe. Methods of cr |
| Modulus of elasticity (E) |
The stress required to produce strain, which may be a change of length (Young's modulus); a twist or shear (modulus); a twist or sheat (modulus or rigidity); or a change of volume (bulk modulus), expressed in dynes per square centimeter. |
| Mole |
See impact moling. |
| Mole ploughing |
Burying a pipeline by pulling a plough through the ground while a continuous length of pipe is fed into the top of the plough and laid out underground from the tail of the plough. An alternate ploughing technique may use a plough blade with a bullet |
| Molecular weight distribution |
The ratio of the weight average molecular weight to the number average molecular weight. This gives a preliminary indication of the range of molecular weights. |
| Moling |
A minimum excavation procedure for the construction of pipelines. In collection system re-engineering, moling is typically used as a form of on line replacement, breaking aside the existing sewer fabric and pulling through a new structural lining. |
| Moment of Inertia |
Function of some property of a body or figure - such as weight, mass, volume, area, length, or position, equal to the summation of the products of the elementary portions by the squares of their distances from a given axis. |
| Moment, Bending |
The moment which produces bending in a beam or other structure. It is measured by the algebraic sum of the products of all the forces multiplied by their respective lever arms. |
| Muck |
As a noun, it means the same as spoil. As a verb, it means to dig as in "muck out the hole." |
| Multiple ring brick sewer |
A brick sewer that consists of three or more layers of bricks. |
| Multistaged new installation |
To plan and undertake projects with regard to a phased/milestone schedule. |
