Presentation GMAW

Mechanized
Mechanized
Gas
Gas
Metal Arc
Metal Arc
Welding (Auto GMAW)
Welding (Auto GMAW)
for
for
Qurayah Seawater Pipelines
Qurayah Seawater Pipelines


Before Start Welding
Before Start Welding
1. Approval of GMAW Process from CSD.
2. Approval of WPS & PQR.
3. Inspection of Welding Consumables
4. Welder and welding Operator
Qualification.
5. Welding Machine Calibration.
6. Approval of NDT Procedure.
7. Approval of NDT Personnel.

Approval of GMAW Process from
Approval of GMAW Process from
CSD
CSD
SAES-W-012: 5.4.1
SAES-W-012: 5.4.1
d) Automatic/machine welding using the GMAW
d) Automatic/machine welding using the GMAW
process Requires approval by CSD. A
process Requires approval by CSD. A
computerized automated ultrasonic inspection
computerized automated ultrasonic inspection
system, approved by Inspection Department,
system, approved by Inspection Department,
must be used.
must be used.
Contractor has to submit complete details
Contractor has to submit complete details
about their GMAW process, controls like which
about their GMAW process, controls like which
are the parameters are controlled by M/c and
are the parameters are controlled by M/c and
by welders , Gas & gas mixtures to be used
by welders , Gas & gas mixtures to be used
etc. to CSD for approval.
etc. to CSD for approval.


Approval of WPS & PQR

Approval of WPS & PQR
.
.
SAES-W-012: 7

7.1.1 . All welding procedures to be used shall be submitted to
Saudi Aramco as a complete package prior to the start of work.
The package of welding procedures, qualification test records, and
weld maps/tables shall be submitted for the technical approval by
CSD.

7.1.5 . Welding shall not commence until the welding package has
been approved for application by Saudi Aramco inspector and
returned to the fabricator. Any welding prior to the approval of
the welding package is subject to rejection at the sole option of
Saudi Aramco inspector.

7.1.6 . After approval by Saudi Aramco inspector, the fabricator
shall issue copies of the approved Welding Procedures and Weld
Table to the Saudi Aramco Inspector and PMT prior to the start of
fabrication.

7.2.1. All WPSs and PQRs shall conform to the latest edition of
the relevant Code (API STD 1104 or ASME SEC IX, as
appropriate). Procedures that comply with a previous edition but
not the current edition of the relevant Code are not acceptable,
Procedures no longer conforming to the latest Code edition shall
be revised and requalified.

Inspection of Welding Consumables
Inspection of Welding Consumables
SAES-W-012 :6.7

Shielding gases shall conform to the following
requirements:

6.7.1 Carbon dioxide (CO2): Federal Specification BC-C-
101, Type B or Compressed Gas Association CGA G-6.2,
Type F.

6.7.2 Argon (Ar): Compressed Gas Association CGA G-
11.1, Grade A.

6.7.3 The requirements for other gases and gas mixtures
shall be submitted to CSD for approval.

So contractor has to submit the certificate of shielding
gases to comply with above requirements.


Welder and welding Operator
Welder and welding Operator
Qualification
Qualification
SAES-W-012: 8

8.1 All welders, welding operators, shall be
qualified in accordance with either ASME
SEC IX or API STD 1104 and SAEP-321,

SAEP-322, SAEP-323, and SAEP-324, as
applicable, for all welding, including tack,
temporary, and repair welds.

8.3 Performance qualification tests shall
not be performed on production joints on
Saudi Aramco work


Welding Machine Calibration
Welding Machine Calibration
.
.
SAES-W-012: 18
18.2 Welding power supplies shall be
calibrated in accordance with BS 7570 or
an approved equivalent if impact
toughness test is required by the
applicable company or industry
specifications or codes. Calibration records
shall be available to Saudi Aramco
Inspection upon request.



Approval of NDT Procedure and NDT Personnel
Approval of NDT Procedure and NDT Personnel

SAES-W-012: 16
16.1.1. Nondestructive Testing (NDT) inspection procedures shall be established in

accordance with ASME SEC V. A written procedure for each inspection method and
technique, including acceptance criteria, to be used shall be submitted to Inspection
Department for approval. Qualification of the procedure by the contractor may be
required, as determined by Saudi Aramco Inspection. Inspection procedures in
conformance with other standards are acceptable only with the approval of Inspection
Department. NDT performed without approved procedures shall be considered
unacceptable.
16.1.6 All NDT personnel shall be qualified in accordance with SAEP-1140 or SAEP-
1142, as applicable.

SAEP-1142

4.2 Any organization supplying, employing, or delegating NDT personnel shall have a
written practice or procedure covering NDT personnel training, experience,
qualification, and certification. This written practice shall meet or exceed the
minimum requirements of ANSI/ASNT CP-189 (latest edition) plus the additions and
clarifications outlined in this SAEP. The organization's NDT personnel qualification and
certification procedure shall be submitted to the Saudi Aramco Inspection
Department, Dhahran, for review and approval prior to the commencement of any
NDT operations.

4.4 Personnel responsible for interpretation of or affecting the results of NDT
operations shall be certified to a minimum of Level II per the certifying organization's
written practice.

Schedule ‘Q’ Attachment VI (Replace Table of Attachment IV)
Personnel qualification procedure approval and Personnel qualification approval not
required when NDT is subcontracted to an approved in-kingdom sub contractor. NDT
technician performance shall be monitored by Contractor on all projects.

Comparison of SMAW
Comparison of SMAW
(
(
Shield Metal Arc Welding ,
Shield Metal Arc Welding ,
Manual welding
Manual welding
) with Auto
) with Auto
GMAW
GMAW
Note: Applicable only in Qurayah Seawater pipelines
Note: Applicable only in Qurayah Seawater pipelines


Major Points
Major Points

Purpose or Use in Qurayah Pipelines

Joint Design

Fitup or Joint preparation

Clamps for Fitup


Preheating

Shielding Gas

Electrode / Filler wire

Control

Production

Defects

NDT


Purpose or
Purpose or
Use
Use
in Qurayah Pipelines
in Qurayah Pipelines

SMAW
Welding of Tie-in , Road , Railway & Pipeline crossing
sections.

GMAW
Mainline welding (Long sections)

Joint Design
Joint Design

SMAW
Single ‘ V ‘ with Root Gap
Groove Angle = 60º (+10º, - 0º)
Bevel Angle = 30º
Root Face = 1.6mm
Root Gap = 2-3 mm


GMAW
Single ‘ U ‘ without Root
Gap


Bevel preparation
Bevel preparation

SMAW
By gas cutting and
grinding

GMAW
Using Beveling
Machine
Beveling Machine


Clamps for Fitup

Clamps for Fitup

SMAW: Using external
Clamp

GMAW: Using Internal
Clamp
SAES-W-012 :10.4

An internal line-up clamp shall be
used if the pipe diameter is 16
inches or larger, except for tie-in
welds or cement-lined pipe. Special
shoes must be used for internally
coated pipe to ensure the coating is
not damaged.

10.4.2 The internal line-up clamp
shall not be removed before the
completion of the root bead. For
external clamps, the root bead
must be at least 50% complete
prior to removal.

External clamp

Internal Clamp


Shielding Gas & Electrode / Filler wire

Shielding Gas & Electrode / Filler wire

SMAW:
Shielding gas – Nil
Electrode – Flux coated electrode
E6010- Root welding, E8018C3 – Hot, Fill & Cap pass
Direction of Welding – Uphill ( from Down to Up)
Preheat – By Gas Torch

GMAW:
Shielding gas – 100% CO2 - for Root, hot & Fill pass1 welding
70% CO2+ 30% Argon – for Fill 2 & Cap pass
Electrode: Bare Filler wire, ER 70 S6 – for All passes
Direction of Welding – Down hill ( from Top to Down)
Preheat - By Induction heating and Torch


Control & Production
Control & Production

SMAW:

Completely Manual, all parameters to be
adjusted by welders.

Slow process and production also less
compared with GMAW

GMAW:


Filler wire feed automatically.

All parameter fixed in m/c and Operator can
adjust a bit of oscillation and stick out.

High speed process, weld deposition less and
production very high.
SAES –W-012 -7.4.18
Maximum Tolerance limits of Parameters for
Automatic welding:

travel speed: ±20% of the actual PQR
value

voltage range: ±10% of the actual PQR
value

current range: ±15% of the actual PQR
value

Auto GMAW welding head


Defects & NDT
Defects & NDT

SMAW
Defects : Most common defects are Slag, Porosity, Lack of root fusion and
penetration
NDT : 100% Radiography

SAES-W-012, 10.4.2:
External line-up clamp may be used for pipe diameter 16 inches or larger if approved
by CSD Welding Engineer with a condition that 100% radiography is performed to
the production welds.

GMAW
Defects: Common defect is Side wall lack of fusion. Due to high rejection, it may
affect project repair rate.
NDT : 100% Automatic- Ultrasonic Testing
SAES-W-012, 16.6:
Exception:
For girth welds made with an automatic/mechanized GMAW process using the short-
circuiting mode, 100% inspection using a computerized automated ultrasonic
inspection system is required.

16.6.1.1.3 Additional radiography
The following weld joints are also required to be radiographed, in addition to the
extent of NDT previously specified.
a) All welds of the first day's production for a particular job or a minimum of the first
forty (40) production joints, whichever is greater. For consecutive, similar jobs (e.g.,
multiple flowlines), the first five (5) joints on the subsequent jobs shall be
radiographed.


NDT Continue…
NDT Continue…
SAES-W-012, 16
SAES-W-012, 16

16.1.8 Inspection of all welds shall include a band

16.1.8 Inspection of all welds shall include a band
of base metal at least 25.4 mm wide on each side
of base metal at least 25.4 mm wide on each side
of the weld.
of the weld.

16.3.2 A computerized automatic ultrasonic system must
be used for all welding performed with an
automatic/mechanized GMAW welding system operating
in the short-circuiting mode. The system must be
approved by Inspection Department.

16.3.3 When a computerized automatic ultrasonic system
is used, it shall be operated within the equivalent of one
hour's production from joints currently being welded. For
normal jobs, it is expected that the UT system will be
within approximately 10 joints of the last completed
weld. (repetitive defects do not occur for a large number of consecutive welds)


Repair
Repair

SAES-W-012 7.4.16.
Repair may be conducted using a welding procedure
different than the original welding procedure used to weld
the joint with the conditions:

a) Repair procedures shall be qualified for each base metal
thickness range as listed in API STD 1104.


b) The weld deposit thickness used for the procedure
qualification shall be the maximum qualified deposit
thickness unless a full thickness procedure qualification is
conducted.

17.1: Welds may be repaired twice. If the weld is still not
acceptable after the second repair, then Saudi Aramco
Inspection has the sole authority for the decision to permit
additional repair attempts or to require that the entire weld
be cut out.

17.4 : All repaired welds shall, as a minimum, be inspected
using the original testing method. Additional test methods
may also be required, if deemed necessary by the
authorized Saudi Aramco inspector. ( Normally UT &
Radiography )


Some Important Points on Pipeline Welding
Some Important Points on Pipeline Welding

The second or hot pass shall be added as soon as possible
after the completion of the root pass, but shall not exceed 5
minutes for vertical down welding with cellulosic electrodes
or 15 minutes for vertical up welding. If a production joint
exceeds the specified time lapse, then magnetic particle
examination of the root pass shall be conducted and the joint
preheated to 60°C minimum or the preheat specified in the
procedure, whichever is greater, prior to making the hot

pass. If the joint has been completed without MT of the root
pass, then supplemental NDT of the joint, as specified by
Inspection, shall be conducted.

The hot pass shall be made while the pipe is still fully
supported by the sideboom tractor or supports.

The weld joint shall be completed within 24 hours of starting.

The working clearance shall not be less than 900 mm all
around the pipe.

For pipelines greater than 16 inch diameter, at least two
welders shall be used, operating simultaneously and in
opposite quadrants.


Some pictures of GMAW Machine
Some pictures of GMAW Machine
(Saipem)
(Saipem)
Control unit




Thank You
Thank You