Glossary

Abandonment

Throwing ‘dead’ a gas main or service

Anchor stakes

Used to anchor pipe pushing machines into the ground

Annular space or annulus

The space between an inserted pipe and the host pipe

Applicator Gun, SVI

A special hinged applicator gun used with the cartridges in SVI foam kits

Auger Boring

Method of forming a bore, usually from a drive pit by means of a rotating cutting head. Spoil is removed back to the drive pit by helically wound auger flights rotating in a steel casing.

Back reamer

Cutting head attached to the leading end of a drill string to enlarge the pilot bore during pull-back to enable to product to be installed

Bagging off

Temporarily flow stopping a gas main using inflatable bags

Blackburn Method

The original name for the Live Gas Mains Insertion technique which was first used in the town of Blackburn

Blind Drill & Tap

Allows inserted gas main to be drilled, for gaining access to new main, without the risk of damaging the PE

Bore

Void which is created to receive a pipe, conduit or cable

Carrier pipe

Pipe to be rehabilitated by any trenchless renovation method

Caulking

General term which, in trenchless technology, refers to methods by which joints may be closed within a pipeline or between lining segments

CCTV camera surveys

Surveys of underground pipes are carried out to …

Central drum

SVI pipe coil trailers have a central rotating drum to aid dispensing and preventing the PE pipe to be pulled through the trailer

Chemical grouting

Method for the treatment of the ground around a shaft or pipeline, using non-cementitious compounds, in order to facilitate the installation of an underground structure

Circumferential cutting

A specially designed wheeled cutting system allows large diameter cast iron, ductile iron or steel pipes up to 60cm/24” diameter to be cut

Close-fit lining

Method of lining with a continuous pipe for which the cross section is reduced to facilitate installation and reverted after installation to provide a close fit to the existing pipe.

Continuous Sliplining

See Lining with Continuous Pipe

Conventional Trenching

Method in which access is gained by excavation from ground level to the required level for the installation, maintenance or inspection of a pipe. The excavation is then backfilled and the surface reinstated

Crush Lining

See Pipe Eating

Cured-in-Place Pipe

See Lining with Cured-in-Place Pipes

Dead Endseal™

A SVI foam-filled fabric muff used on dead inserted gas mains

Directional Drilling

Steerable method of installing pipes, conduits and cables in a shallow arc using a surface launched rig.

Discrete Sliplining

Lining with Discrete Pipes

Disposable gland box

A SVI Lynontec gland box, used in Live Mains Insertion and designed to be left on the end of the inserted PE as an end seal

Drainblock Bag™

A SVI product for remotely sealing off disused drains or sewer laterals where they meet the parent main

Drill String/Stem

The total length of drill rods/pipes, bit, swivel joint etc. in a bore

Drilling Fluid/Mud

Mixture of water and, usually, bentonite or polymer continuously pumped to the cutting head or drill bit to facilitate the removal of cuttings, stabilise the bore, cool the head and lubricate the passage of the product pipe.

Dry Bore

Method of creating a bore without the use of a drilling fluid. Usually associated with guided impact moling, but may also apply to some rotary methods.

Duct sealing

Sealing the annular space in ducts to prevent the ingress of water etc.

Earth Piercing

Term commonly used in the US as an alternative to Impact Moling

Elbow tester

Used in Live Service Insertion to detect any sharp bends or elbows in a service which might lead to incorrect length measurements being recorded

Endseal™

A SVI fabric muff which is fixed around the end of an inserted pipe and host pipe and filled with expanding resin foam to seal off the annular space. Used in Live Gas Mains Insertion (see also Mini Endseal)

Expander

A tool which enlarges a pilot bore during a pull-back operation by compression of the surrounding ground rather than by excavation.

Extension tube

One metre extension tubes fitted to the Mini Purge Ejector to achieve required distance above ground

Fire retardant encapsulation

A tailored fabric muff, injected with fire retardant material, is used to encapsulate the cut sections of service in the SVI Live Riser Transfer technique, providing a 30 minute fire check

Flame trap

Fitted to a SVI Test End

Flexirod

Supplied with a SVI Live Service Insertion equipment kit and used in measuring the service and knocking out the pip in the nose cone

Foam Kit

Generic term for SVI Foambag™ and Foamstop™ kits

Foambag™

A SVI patented system for flow stopping sections of gas mains to be abandoned

Foambag™ capsule

A specially designed SVI Foambag™ which is housed in a capsule for use in the Live Stub End Abandonment technique

Foamcap™

A lightweight alternative to metal caps offered by SVI  for sealing off abandoned mains

Foaming off

Using the SVI Foamabg™ system to permanently sealing off a gas main prior to abandonment

Foampack™

A sealed two-part sachet supplied by SVI containing resin and hardener. When central spine is removed, foam is mixed together ready for injection

Foamstop™

A SVI technique which provides a no-gas method of service cut-off for small diameter low pressure gas pipes

Foamstop™ tee

Used in SVI Live Service Transfer to allow drilling of the service in no-gas conditions and injection of FOAMSTOP™ foam

Fold & Form Lining

Method of pipeline rehabilitation I which a liner is folded to reduce its size before insertion and reversion to its original shape by the application of pressure or heat

Four wheel cutter

Hand held SVI tool for cutting steel service pipes; equipped with four heavy-duty wheels designed for use where a complete turn is impossible

FULLSEAL™, SVI

Annular sealant for inserted gas services

Grout filling

Specially formulated cementitious grout is used to seal off underground voids

Grout gun

A SVI barrel applicator gun used for injecting grout, for example during dead service insertion

Grouting

Method of filling voids, usually with cementitious grout

Guided Auger Boring

Method of auger boring in which the guidance mechanism is sited in the draft shaft

Guided Boring

See Guided Drilling

Guided Drilling

Method for the installation of pipes 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. The necessary deviation during the pilot boring is provided by a slanted face to the drill head, eccentric fluid jets or a combination of these, usually in conjunction with a locator.

High Integrity FOAMBAG, SVI

High performance FOAMBAG™ developed for use in the nuclear sector

Hydraulic pipe pushing machine

See pushing machines

Impact Moling

Method of creating a bore using a pneumatic or hydraulic hammer within a casing. Usually associated with non-steered or limited steering devices relying on the resistance of the ground for forward movement. The spoil is displaced, not removed.

Impact Ramming

See Pipe Ramming

In Line/On Line Replacement

See Replacement

Insert shells

Fitted to SVI pipe pushing machines to accommodate different pipe diameters

Insertion Seal™

A SVI expanding resin foam injected into the annular space between an inserted gas pipe and host pipe in order to throw it ‘dead’

Iris Stop

A mechanical device used to temporarily flow stop a gas main

Isolation, live service

A Steve Vick International Technique for isolating steel services prior to Live Insertion or abandonment

Isolator Clamp

A specially designed SVI wrap-around clamp which is fixed to a steel service during Live Gas Service Isolation

Jet Cutting

Guided boring method using pressurised fluid jets for soil cutting

Joint Sealing

Method in which an inflatable packer is inserted into a pipeline to span a leaking joint, resin or grout being injected until the joint is sealed and the packer then removed

Lining with close-fit pipe

Method of lining with a continuous pipe for which the cross section is reduced to facilitate installation and reverted after installation to provide a close fit to the existing pipe

Lining with continuous pipe

Method of lining with a pipe made continuous for the length of the section to be renovated prior to insertion (and which has not been shaped to give a cross section diameter smaller than its final diameter after installation)

Lining with cured-in-place pipe

Method of lining with a flexible tube impregnated with a thermosetting resin which produces a pipe after resin cure

Lining with discrete pipe

Method of lining with pipes shorter than the section to be renovated which are not jointed prior to insertion to form a continuous pipe and which have not been shaped to give them a cross section diameter smaller than their final diameter after installation

Lining with inserted hose

Method of lining with a loose fit reinforced hose to provide a pipe lining such that fluids may be conveyed under pressure

Lining with pipe segments

Method of lining with pipe sections made of at least two pieces with both longitudinal and circumferential joints

Lining with spirally wound pipe

Method of lining with a profiled strip, spirally wound to form a continuous pipe after installation

Live Gas Mains Insertion

A technique used in renovation of gas mains. A new PE pipe is inserted into the old metal main. By using a special SVI gland box, the old main is kept live throughout the insertion process and customers remain on gas.

Live Gas Service Insertion

A method of renewing live, metal gas services by inserting PE; avoids decommissioning the main and excavating in the road or footpath

Live head, SVI

A perforated steel conical head fitted to the leading end of PE pipe during Live Gas Mains Insertion; allows gas to flow in and out of the pipe

Live Insertion

Method of installation of a liner whilst the product pipe remains in service

Live Riser Transfer

A technique offered by SVI which allows a gas riser within a building to be partly renewed or transferred to a new main without decommissioning it

Live Service Isolator

A SVI technique for isolating steel services prior to Live Insertion or abandonment

Localised repair

Repair work on a pipe, particularly sewerage, for lengths less than the run between two adjacent access points

Locator

An electronic instrument used to determine the position and strength of electro-magnetic signals emitted from a transmitter sonde in the pilot head of a boring system, in an impact moling tool or from existing underground services which have been energised. Sometimes referred to as a Walkover System

Lyontec gland box

A lightweight SVI gland box used in Live Gas Mains Insertion to allow PE to be inserted into a ‘live’ cast iron main. Designed to be left in the ground

Lyontec™, large diameter

SVI Gland boxes designed for mains of 12” and above fitted with safety valve

Mains Insertion

See Live Gas Mains Insertion

Man entry

Description of any operation which requires an operative to enter a pipe, duct or bore.

Microtunnelling

Method of steerable remote control pipe jacking to install pipes of internal diameter less than that permissible for man-entry. In the US, the term is used to describe remote control continuous pipe jacking in all diameters

Midi Rig

Steerable surfaced launched drilling equipment for the installation of pipes, conduits and cables. Applied to intermediate sized drilling machines or large guided boring machines.

Mini End Seals

A fabric muff which is fixed around the end of an inserted pipe and host pipe and filled with expanding resin foam to seal off the annular space. Used in the Live Service Insertion technique

Mini Horizontal Directional Drilling

An alternative term for Guided Drilling

Modified Wask Night Cap, SVI

Used to drill live gas mains in no gas conditions during foaming off operations

Mole

See Impact Moling

Mole ploughing

Method of installing a pipeline by pulling a plough through the ground whilst a continuous length of pipe is fed into the top of the plough and buried in the ground from the tail end

Narrow trenching

Method of excavation of a trench up to 100mm wider than the outside diameter of the service to be installed – usually employing either a rockwheel or chain type trencher

Night Cap, Wask Modified.

Used to drill live gas mains in no gas conditions during foaming off operations

No-gas conditions

Live gas pipes are rendered safe to cut during various renovation/replacement techniques using valves, stoppers and gland boxes

Nominal Size

Size pipe in terms of internal working diameter

Non-man entry

Size of pipe, duct or bore less than that for man-entry

Nose cone

Rubber, nylon or plastic device with fins fitted to the end of a PE pipe before it is inserted into a carrier pipe (used in Live Service Insertion, Sealback™ etc.)

Open Cut

See Conventional Trenching

Ovality

The difference between the maximum and minimum diameter divided by the mean diameter at any one cross section of a pipe – generally expressed as a percentage

PE

Polyethylene pipe used throughout the utilities sector

Pilot Bore

First, usually steerable, pass of any boring operation which later required back-reaming or other enlargement

Pipe bursting

Size-for-size replacement or upsize replacement of gas and water mains and sewers by splitting the host pipe and drawing in a new (usually PE) pipe

Pipe Bursting

Replacement method in which an existing pipe is broken by brittle fracture using mechanically applied force from within. The pipe fragments are forced into the surrounding ground. At the same time a new pipe – of the same or larger diameter – is drawn in

Pipe clamp

A device fitted to pipe pushing machines which grips the PE as the rams move back prior to pushing in the next section of pipe

Pipe Coil Trailer

Trailer designed to transport and dispense coils of PE and other flexible pipe

Pipe Eating

Replacement method, usually based on microtunnelling, in which a defective pipe is excavated together with the surrounding ground and a new pipe installed.

Pipe Jacking

Method for directly installing pipes behind a shield machine by hydraulic or other jacking from a drive shaft such that the pipes form a continuous string in the ground

Pipe Pulling

Method of replacing small diameter pipes where a new product pipe is attached to the existing pipe which is then pulled out of the ground

Pipe Pushing Machines

See Pushing Machines

Pipe Ramming

Non-steerable method of forming a bore by driving a steel casing – usually open-ended – with a percussive hammer from a drive pit. The soil may be removed by augering, jetting or compressed air.

Pipe Splitting

Replacement method for breaking an existing pipe by longitudinal slitting. At the same time a new pipe of the same or larger diameter may be drawn in behind the splitting tool

Pneumatic pipe pushing machine

See pushing  machines

Power Pack

Supplied as an optional extra with Hydraulic Pipe Pushing Machines

PU foam

Polyurethane resin foam which is used in SVI Foambag™, Foampack™, Insertion Seal and End Seal™ kits. The resin and hardener are mixed together immediately prior to use; the foam expands and cures within 15 to 30 minutes depending on formulation and ambient temperature

Purge Ejector, Mini

SVI’s smaller version of the traditional Venturi Purge Ejector for purging gas from metallic and PE gas mains during pipe abandonment.

Purging

See purge ejector, mini

Pushing machine

A machine, either manually, pneumatically or hydraulically operated, designed to push a new pipe into a carrier pipe.

Reaming tool

Small reaming tool for PE services used prior to fitting nose cone in Live Service Insertion

Reception/Exit Shaft or Pit

Excavation into which trenchless technology equipment is driven and may be recovered during the installation or renovation of a product pipe, conduit or cable

Red Mini Endseal™

Used exclusively in the SVI Live Service Insertion technique

Rehabilitation

All methods for restoring or upgrading the performance of an existing pipeline system

Reinstatement

Method of backfilling, compaction and re-surfacing of any excavation in order to restore the surface and underlying structure to enable it to perform its original function

Removal Tool, Live Service

A tool which easily removes a section of metallic pipe which has been ‘live’ inserted with PE

Renovation

Methods of rehabilitation in which all or part of the original fabric of a pipeline is incorporated and its current performance improved

Replacement

Methods of rehabilitation of an existing pipeline system by the installation of a new system, either on or off the existing line, without incorporating the original fabric

Re-rounder

Device fitted to pipe coil trailers to help remove ovality from PE and assist smooth dispensing

Rerounding

Preparatory operation in which an expansion devise is inserted into a distorted pipe to return it to a circular cross section. Usually carried out prior to the insertion of a permanent liner or supporting band

Resin Injection

Method used in the localised repair of pipes, usually sewers, by injection into cracks, defects or cavities of a resin formulation which subsequently cures to prevent leakage and further deterioration

Reversible standpipes

Allow no-gas injection of Insertion Seal during Live Mains Insertion procedure

Robot

Remote control device with close circuit television (CCTV) monitoring used mainly in localised repair work such as cutting away obstructions, re-opening lateral connections, grinding and re-filling defective areas and injecting resin into cracks and cavities

Rod Pushing

Method of forming a pilot bore by driving a closed pipe head with rigid attachment from a launch pit into the soil which is displaced.

Roller bracket

Fitted to pipe pushing machines to guide PE into jaws

Sealback™

A technique which enables short sections of low-pressure gas main to be replaced  from a remote location, to where it intersects its parent pipeline. Carried out by SVI as a Special Contract Service

Service pushing machine

A SVI manual pushing machine designed for inserting PE into metal gas services

Service Taper Tool, SVI

Safe and Easy method of chamfering PE services prior to insertion

Serviflex™

ServiFlex® is a gas service pipe replacement system capable of negotiating long and short radius bends. Supplied by Synthotech Special Products Ltd

Sewer laterals, sealing off

See Drainblock Bag™

Shell inserts

Fitted to SVI pipe pushing machines to accommodate different pipe diameters

Shoot bolt

Used on SVI pipe coil trailers to secure drum bars onto central rotating drum

Sliplining

A method of inserting a new pipe within a defunct host pipe

Standpipes

Used for launching SVI Foambags™ into live gas mains and services in no-gas conditions

Steve Vick Drill

A drill which allows a hole up to 44mm to be cut in live gas pipes running at pressures up to 2 bar in ‘no-gas’ conditions.

Stub ends

Short lengths of gas main typically left live, although defunct. Can be finally abandoned using  the SVI Live Stub End Abandonment technique

Taper Tool, SVI

Safe and Easy method of chamfering PE services prior to insertion

Test Ends

In Live Mains Insertion, fitted to the end of the PE pipe prior to insertion to allow pressure testing of the pipe and purging air; comes with flame trap

Trenchless technology

Methods of replacing or renovating underground utility services without digging trenches

Under pressure drill

A SVI drill which allows live gas pipes to be drilled in ‘no-gas’ conditions

Under Pressure Tee, SVI

A special fitting used in Live Service Transfer and Live Riser Transfer to allow a new section of service to be connected to the old service remaining in commission

Venturi

A technique used in the Mini Purge Ejector to create a vacuum in a gas pipe to allow it to be purged

Wask Night Cap, modified

Used to drill live gas mains in no gas conditions during foaming off operations

Window cutting

A method of cutting a metal pipe to gain access to a previously inserted carrier pipe

Yellow Mini Endseal™

Used exclusively for dead service insertion

Segmental Lining

See Lining with pipe segments

Segmental Sliplining

See Lining with Discrete Pipes

Sleeve Pipe

Pipe installed as external protection to a product pipe

Sliplining

General term used to describe methods of lining with continuous pipes and lining with discrete pipes

Soft Lining

See Lining with Cured-in-Place Pipes

Spacer Block

Device used to extend the distance that the hydraulic rams within a jacking system can propel the pipeline

Spiral Lining

See Lining with Spirally Wound Pipes

Spray Lining

Method for applying a lining, usually of cement mortar or resin, by a rotating spray head which is winched through an existing pipeline

SSES

Sewer System Evaluation Survey of tributary sewer systems with levels of infiltration and inflow

Standard Dimensional Ratio (SDR)

The ratio of minimum outside diameter of a pipe to wall thickness

Steerable Moling

Similar to impact moling with a limited steering capability

Swagelining

Method of lining with close-fit pipes in which a temporary reduction in diameter is achieved by passing it through one or more dies which may be heated.

Target Shaft or Pit

See Reception/Exit Shaft or Pit

Thrust Boring

Unpreferred term loosely applied to various trenchless installation methods. See Rod Pushing

Thrust Jacking

Method in which a pipe is jacked through the ground without mechanical excavation of  material from the front of the pipeline

Thrust Pit

See Drive/Entry Shaft or Pit

Drive/Entry Shaft or Pit

Excavation from which trenchless technology equipment is launched for the installation or renovation of a pipeline, conduit or cable.

Thrust Ring

Load spreading device to transfer force from the hydraulic rams onto the pipeline in a pipe jack operation

Trenching

See Conventional Trenching

Trenchless Technology

Methods for utility and other pipe installation, rehabilitation, replacement, renovation, repair, inspection, location and leak detection with minimum excavation from the ground surface

Tunnel Boring Machine

A machine that excavates a tunnel by drilling out the face to full size in one operation.

Uncased Bore

Self supporting bore without a lining or inserted pipe – whether temporary or permanent

Upsizing

Method in which the cross sectional area of an existing pipeline is increased by replacing it with a larger diameter pipe

Utility Corridor

Duct in which two or more different utility services are installed with access for maintenance. Also referred to as a Common Utility Tunnel, Common Duct or Utilidor.

Walkover System

See Locator

Washover Pipe

Rotating drill pipe or larger diameter than the pilot drill and placed around it with its leading edge less far advanced. Its purpose is to provide stiffness to the drilling pipe in order to maintain steering control over long bores, to reduce friction between the drill string and the soil and to facilitate mud circulation. See Directional Drilling

Water Jetting

Method for the internal cleansing of pipelines using high pressure water jets