January 2011 Tube Products International
53
& pipel ine products
Video inspection and internal weld scanning
from a single source
Optical Metrology Services Ltd (OMS)
specialises in measuring equipment
and consulting services for use within
the pipe manufacturing and pipeline
construction sectors, both onshore and
offshore. A key focus for OMS is in the
dimensional measurement of oil and
gas pipes or other structures such as
military gun barrels, processing industry
tubes or manufactured cylindrical
objects, where dimensions are critical.
Hugh Davies, head of sales at OMS,
discusses how video inspection and
internal weld scanning tools are being
used to check weld quality on pipes
and other deepsea subsea oil and gas
structures.
When inspecting the inside of pipelines
and other subsea structures such as
valve manifolds, video inspection can
provide close-up views of features that
are otherwise very difficult to access.
Video inspection enables inspectors to
assess a wide variety of features relating
to welds, internal corrosion, internal
structure, coatings and so on.
Whether onshore or offshore, inspectors
need the best possible lighting and
video technology, as well as a variety
of methods of deploying the video tools
inside different types of structures.
Optical Metrology Services (OMS) Ltd
has a wide range of advanced video
inspection equipment. This includes the
latest pan-and-tilt camera technology,
auto-focus zoom lenses, tractor systems
and motorised cable reels.
For specialist weld inspection
applications, OMS designs and
manufactures unique digital imaging
solutions, which can be deployed inside
hot pipes during production welding.
OMS also offers tool operators and
qualified weld inspectors, who provide a
full turnkey solution. Bespoke designed
and manufactured systems can be
delivered to solve the most challenging
client inspection requirements.
For ‘reeling trials’, OMS offers video
inspection services that can be
combined with laser scanning of pipes
to provide a combination of imaging
and dimensional mapping of pipes or
features in 3D.
OMS inspection reports provide
comprehensive independent inspection
records, which can include still images,
video records, interpretation and
analysis.
OMS clients can access the best
technology and skilled, experienced
operators to deliver the best possible
video inspection in challenging pipeline
engineering applications, whether in
QC, standards compliance, or in special
projects.
In oil and gas pipes, the quality of the
root pass of a weld is critical to the
structural integrity of the girth weld.
Oil and gas companies therefore have
stringent inspection requirements for
checking welds. However, few if any
tools currently exist on the market that
can perform this kind of work. Welding
of clad pipe is especially challenging
and requires accurate measurement of
the weld area in order to ensure zero
defects and to avoid the delay and cost
of a weld cut out later in the welding
process.
Using its groundbreaking internal weld
inspection system, in combination
with video-based inspection systems,
OMS offers customers comprehensive
inspection services for checking the
internal size and shape of girth welds on
pipes that are destined for use in deepsea
subsea oil and gas applications.
The Internal Weld Scanning Tool is a
unique system that internally scans
welds inside pipes, both visually and
dimensionally, enabling the quality of
the root weld to be assessed quickly
and confidently. The tool is available on
a service contract or rental basis, with a
trained OMS inspector.
The service is available both onshore
and offshore at different stages of
the pipe welding process. The internal
weld scanning tool can be used on
corrosion-resistant alloy-lined pipe
to identify sour (aggressive) ingress
points, in both clad butt-weld and
clad weld inlay applications. The tool
can also be used to improve weld
procedure development efficiency and
to check the root weld and geometry
before next passes are deposited. The
technology provides similar uses in
fatigue-sensitive applications (SCRs)
where the pipe is subject to higher
dynamic stresses.
Using OMS’ internal weld scanning
service, a wide range of weld features
can be detected, including root
penetration, root concavity, cracks,
lack of penetration, discolouration,
oxidisation, surface porosity and burn-
through.
The Internal Weld Scanning Tool can
be mounted to a purge dam, with an
integrated camera for positioning and
inspection. Pipe can be inspected whilst
it is being spooled onto a pipe laying
vessel or during stalk fabrication/tie-in.
Here, the tool is retrieved using a winch
and wire system, with weld positioning
controlled by a camera and precision
motorised system.
The service includes integrated
analysis software, which enables the
documentation and interpretation
of internal weld features, as well as
the measurement of cross-sectional
data. Scanning a typical 10", 12" or
14" diameter pipe takes around 45
seconds in total. Once the automated
scanning of the root weld is complete,
the software enables the user to
identify the features of the weld and
measure them. Cross-sections around
the weld, for example, can be chosen
and the main features of the weld then
measured.
The software is also a traceability tool.
Inspectors can choose cross-sections
around the pipe at regular angles and
log any defects as they are found.
The software automatically records
all measurements, as well as typed
comments from the inspector. This
information, including sample images
and cross-sectional profile data, can
then be archived. Logged data can be
directly imported to Microsoft Excel as
part of a weld inspection record.
Optical Metrology Services Limited
– UK
