Glossary

Bevel (to)
To machine the ends of the pipes to form a bevel in preparation for welding

Bevelling
Preparing the ends of the pipes to be welded by machining them so that the angle of the edges is anything but 90°

Bug-and-band
A type of pipeline welding equipment consisting of a welding bug which runs onto a guiding band positioned at the pipe’s joint level

Coating
A layer of material applied over the pipe surface in order to protect it

Coating stall
A station where the coating operations are performed

Cut-back
The distance between the pipe end and the pipe coating

Double-joint
A 24-metre long pipe

Dual torch welding
A welding process which consists of running two weld passes at a time by using two torches simultaneously

Field Joint Coating (FJC)
Operation which coats the space of pipe that has not been coated (coating cut-back) after the welding and testing operations

Flux cored arc welding (FCAW)
An arc welding process that uses a continuously fed consumable electrode containing a shielding flux

Gap
The space between two bevels after pipe alignment

Gas metal arc welding (GMAW)
An arc welding process that uses a shielding gas to protect the molten weld pool from the surrounding atmosphere

Hex-joint
A 72-metre long section composed of six 12-metre long pipes

High-low or hilo
The height difference between the bevel edges after pipe alignment

Hydraulic power unit (HPU)
A machine used to convert electric or diesel power into hydraulic power

Inert gas
A gas which does not react with the electrode or pipe’s base metal, and which shields the molten weld pool from the reactive gases in the atmosphere

Internal line-up clamp (ILUC)
The equipment inserted into the pipes that are to be welded, to hold them together jointly and coaxially for initial welding passes

J-Lay
A deep-water pipe-lay technique in which the pipes are welded in vertical or near vertical (2G) position and then lowered to the seabed floor

Joint
In French, the space between two beveled pipe ends to be filled out with metal during the welding operation

Joint
In English, a 12-metre long pipe

Machine (to)
To prepare a pipe for welding using a tool-machine (“to bevel” is more often used)

Metal active gas welding (MAG welding)
An automatic or semi-automatic welding process which uses a continuous and consumable wire electrode and an active gas to shield the molten weld pool

Metal inert gas welding (MIG welding)
An automatic or semi-automatic welding process which uses a continuous and consumable wire electrode and an inert or semi-inert gas mixture to shield the molten weld pool

Molten weld pool
The liquid part of the electrode and pipe molten metals during the welding operation

Non-destructive test (NDT)
A test to identify weld defects without damaging the pipes or the weld

Pipe-facing machine (PFM)
The equipment used to machine the end of the pipes to be welded in order to form a bevel

Pulsed arc welding
A MIG-MAG process used with an arc mode where current and frequency are controlled independently by the power source and where the wire melts at each current peak

Quad-joint
A 48-metre long section composed of four 12-metre long pipes

Reeling
The operation which consists of spooling lengths of pipelines onto a pipe-lay vessel reel

Shielding gas
An inert, semi-inert or active gas used to protect the molten weld pool from reactive gases

Short arc welding
A MIG-MAG process used with an arc mode where the welding wire melts when it meets the molten weld pool and then provides a short circuit

S-Lay
An offshore pipe-lay technique in which the pipeline is lowered to the sea in a horizontal position

Spoolbase
A shore yard where lengths of pipelines are welded before being spooled off onto pipe-lay vessels, and then transported offshore for laying on the seabed floor

Stalk
In spoolbase operation, a welded pipe section to be welded on the barge

Steel catenary riser (SCR)
A pipeline in a vertical position which extends from the sea surface to the seabed floor

Surface tension transfer (STT)
A GMAW process used with a controlled short-circuit arc mode, developed and patented by the Lincoln Electric Company, and which is used to run the root pass without any support

Tandem welding
A pulsed MAG process which consists of using two welding wires in one torch and in melting them in one molten weld pool

Tungsten inert gas welding (TIG welding)
A welding process which uses non-consumable tungsten electrode and an inert gas to shield the molten weld pool

Turntable
A J-Lay welding station which turns around the pipe

Unreeling
The operation which consists of un-spooling lengths of pipelines from a pipe-lay vessel reel in order to lay them on the seabed floor

Weld bead
The result of the weld pass

Welding arc
An electric arc created by a welding power source between an electrode and the pipe base metal in order to melt both metals

Welding bug
Welding equipment on a guiding band that runs a weld bead in the joint formed by the two pipes that are to be welded

Welding cabin (US) / welding shack (UK)
A cabin positioned at the pipes’ joint level, which contains all the welding equipment

Welding pass
A single progression of welding along the joint formed by the two pipes to be welded

Welding torch
A part of the welding equipment which performs the weld using an electrode

1G position
A pipelaying technique where the welding bug remains in fixed position to perform the weld, while the pipe held in a horizontal position turns round upon itself

2G position
A pipelaying technique where the welding bug performs the weld by turning around the pipe held in a vertical fixed position

5G position
A pipelaying technique where the welding bug performs the weld by turning around the pipe held in a horizontal fixed position

6G position
A pipelaying technique where the welding bug performs the weld by turning around the pipe held in a 45° fixed position