Procedure of

Production welding
ACPL

PROJECT NAME MAHUVA CITY GAS DISTRIBUTION PROJECT

CLIENT GUJARAT GAS LIMITED (GGL)
TPIA M/s. VCS QUALITY SERVICES PVT.LTD.
CONTRACTOR M/s. ANERI CONSTRUCTION PVT.LTD.
JOB PROCEDURE ACPL/GGL/MCGDP/ MAHUVA /JP-03
Rev. 00

Procedure
For
Production Welding

00 For Approval ACPL M/S VCS M/S GGL

Rev. Date Description Prepared By Reviewed By Approved By

1 OF7 Procedure for Welding

 Procedure of
Production welding
ACPL

1 Scope
This document shall be followed for the fabrication of all types of weld joints and repairs
of the weld of Steel Pipeline network for distribution of natural gas network.

2 Applicable Codes & Standards

2.1 Governing Standard

ASME B 31.8 Code for Gas Transmission and Distribution Piping

Systems ASME B 31.8
API 1104 Standard for welding of Pipelines and Related Facilities -
API 1104
2.2 Reference Standard

ASME Sec. II, Part - C Specification for welding Electrodes and Filler Materials

ASME Sec. V. Non Destructive examinassions

ASME Section IX Qualification for welding and brazing

3 Procedural Step

3.1 Health, Safety & Environment

 The approved procedure of Health, Safety & Environment shall be followed during the
execution.
 All equipments used shall have valid equipment Passport.
 All the persons involved in performing the activity shall have valid Safety Passport issued
by GGL.
 All the drivers / operator shall having defensive driving training
 PPEs shall be used as per the PPE’s Matrix approved by GGL.
 Site specific Risk Assessment & risk mitigation action shall be conducted before execution
of activities on daily Basis.
 GGL approved execution Methodology shall refer.
 Site supervisor shall available to control unsafe behavior of entire working crew.
 All Measuring Equipment used shall be calibrated and well maintained.
 CON308 Guideline for Medical Emergency Management shall be referred.
 Tool Box talk with each members of working crew shall be done
 All waste shall be collected separately in waste collection Box i.e. electrodes, Glass,
Canteen Waste, Cotton, Papers.
 All Persons involved in Welding / hot work activity shall use Fire retardant cloth.

2 OF7 Procedure for Welding

 Procedure of
Production welding
ACPL

3.2 Execution
 The root gap shall be accurately checked and shall conform to the qualified welding
procedure. The use of pipe clamp either internal or external is selected considering
requirements of pigging of pipeline in future However, in some case (tie in welds,
flanges, fittings, diameter of pipe 10” etc.) where it is impossible to use internal clamps,
an external line up clamp may be used.
 Approved welding procedure Specification shall be used for production.
 Certified electrodes shall only be used for the welding. Electrode selection shall be done
as per approved WPS.
 Welding Procedure Qualification and Welder’s Qualification Records shall be verified by
GGL / TPIA before starting the welding. No welder shall be permitted to work without the
possession of Welder identity card.
 Welding of various materials under this specification shall be carried out using Shielded
Metal Arc Welding Process (SMAW) with the approval of the Engineer – in – charge/TPIA.

3.2.1 Bevel Cleaning:

 Before welding, all rust and foreign matter shall be removed from the beveled ends by
power-operated tools. This shall be effected inside and outside and for a minimum
distance of 25 mm from the edge of the weld bevel. The bevels shall be thoroughly
inspected at this stage.
 If any of the ends of the pipe joints are damaged to the extent that, in the opinion of
Engineer – in – charge/TPIA, satisfactory weld spacing cannot be successfully done, the
damaged ends shall be cut and beveled to the satisfaction of the Engineer – in –
charge/TPIA with an approved beveling machine. A manual cutting and weld repair of
bevels shall not be allowed. If laminations, split ends or inherent manufacturing defects in
the pipe shall be discovered, the lengths of pipe containing such defects shall be removed
from the line to the satisfaction of Engineer-in-charge/TPIA. On pipes which have been
cut back, a zone extending 25 mm back from the new field bevel, shall be ultrasonically
tested to the requirement of the line pipe specification to ensure freedom from
laminations. The new bevel shall be 100% visual and 100% dye penetrate / MPI tested. A
report shall be written for all testing and records shall be kept.
 Each weld bevel and adjacent 25mm internal / external area shall be free from any Mill
scale / Grease / Dust etc., which shall be achieved by degreasing where applicable,
followed by power brushing.

3.2.2 Alignment Spacing and Fit-up:

 The first pipe shall be positioned on skids (Size Min 6” each) at minimum height of 500
mm above the ground unless approved by the Engineer – in – charge/TPIA.

3 OF7 Procedure for Welding

 Procedure of
Production welding
ACPL

 From the ground and support skids shall be minimum two per pipe, the skid shall have
rubber sheet / sand / soft soil / saw dust bags placed over them to avoid damage to the
pipe coating. Prior to the line up, pipes shall be checked with cleaning / gauging pig to
ensure freedom internal dent or debris.
 Seam orientation of welded pipe shall be selected to ensure that at the circumferential
welds, the longitudinal welds shall be staggered in the top 90 o of the pipeline, or 250 mm
whichever is the lesser. A longitudinal joint shall pass an appurtenance of a structural
element at a minimum distance of 50 mm.
 For pipe of the same nominal wall thickness the circumferential offset shall not exceed 1.6
mm. No hot dressing shall be permitted. When different wall thickness are involved, the
thickness of thicker pipe shall be tapered to a minimum 1:4 by grinding or any other
means approved at site. Alignment and fit- up shall be checked before welding.
 Any branch connection, sleeve, etc. shall be positioned at least 150 mm from any other
adjacent weld.
 The welds for fittings shall be so located that the toe of the weld shall not come within 50
mm of any other adjacent weld.
 When welding pipes of different pipe grade (as directed by Engineer-in-charge/TPIA.)
A special transition piece shall be used. This shall have a minimum of 1:4 taper. The welds
shall be subject to both ultrasonic and radiographic inspection.
 Before commencement of welding works Aneri Construction shall submit Electrode Batch
Certificates to the GGL/TPIA for all electrodes prior to deployment on the project.

3.2.3 Preheating
 As per qualified WPS
 Preheating shall extend to at least 50 mm on both sides of the weld area.
 Preheating temperature shall be maintained over the whole length of the joint during
welding. The CONTRACTOR to check the temperature shall provide temperature
indicating crayons or other temperature indicating devices.
 Upon re-starting of any suspended welding operating (after depositing weld metal of at
least 50% of pipe thickness) and depending on the material, wall thickness and welding
process, a pre-heating of at least. 100 degree C shall be carried out.

3.2.4 Welding
 The welding process to be employed is given in the welding specification any deviation
shall be through the written consent of GGL/TPIA agency. The root gap shall be accurately
checked and shall be as per qualified WPS.
 When an external line up clamp is used, all spaces between bars or at least 60% of the
first pass shall be welded before the clamp is released and the pipe remaining adequately
supported on each side of the joint.

4 OF7 Procedure for Welding

 Procedure of
Production welding
ACPL

 Aneri Construction shall inform GGL/TPIA, if any section of pipeline containing incomplete
welds falls from the skid.
 The root pass of butt joints shall be executed properly so as to achieve full penetration
with complete fusion of the root edges.
 Welding shall not be interrupted during a pass and shall be completed as early as possible.
 Any kind of movement of components, shocks, vibrations, bumping and stresses are
prohibited while welding is in progress.
 Once the deposit of first pass has been started, it must be completed as rapidly as possible
in accordance with the WPS, all interruptions to the welding cycle shall be kept to a
minimum.
 The welding speed shall be within the parameters as that established in the qualified
welding procedure.

3.2.4.1 Cleaning:
 Removing the flux, craters, welding irregularities, slag etc. shall be by means of a power
brush/ power grinding.

3.2.4.2 Removal of alignment clamp: ·

 Alignment Clamps shall not be removed before 60 % completion of the root pass in case
of External clamp, wherein for internal clamp it shall not be removed until whole root
pass is completed.

3.2.4.3 Hot Pass: ·

 Time lapse between completion of root and the commencement of hot pass shall be as
stated in the welding procedure specification (WPS).

3.2.4.4 Filler & Capping:

 After completion of hot pass, all craters, welding irregularities, slag etc, shall be removed
by grinding / brushing. Time lapse between hot pass and filler shall be as per that stated
in the welding procedure specification (WPS).

3.2.4.5 Cleaning & Restarting:

 Every pass shall be cleaned by power brush, and or grinding machines and chisels.
 Weld bead starting and finishing points shall be staggered for every pass.
 Completed weld shall be carefully brushed and cleaned and shall be free from spatter,
slag, surface defects etc.
 Windshield made of metallic frame covered by G.I sheets / canvas as required shall be
provided to enclose the weld and joint, to protect against adverse weather conditions
such as rain / drizzle, wind, etc. where ever applicable, in the opinion of the GGL / TPIA.

5 OF7 Procedure for Welding

 Procedure of
Production welding
ACPL

 All finished welds shall be visually inspected for parallel and axial alignment of the work,
reinforcement, concavity, shrinkage, cracks, undercuts, dimensions of weld porosity and
other surface imperfections noted shall be rectified, to the satisfaction of the contract
specification

3.2.5 NDT:
 100% NDT of the total Main line welding joints and all Tie-in and Fittings joints, Valve
joints shall be carried out. and the results to be recorded in the approved format.

3.2.6 Destructive Testing:

 0.1 % of the weld joint shall be subjected to destructive testing at no extra cost to client.
 The testing of weld coupons shall be conducted at laboratories approved by GGL/TPIA.
 Arc strike outside the bevel surface shall not be permitted. If any such arc strikes are
made, all such areas shall be repaired to the satisfaction of GGL/TPIA.
 Aneri Construction shall submit welder’s performance chart to GGL/ TPIA at site for
review and approval.
 The skids used during welding shall be removed only, after completion of full welding
operation.
 RT shall examine the completed weld / joints of the pipes having different wall thickness
and records shall be kept.
 In addition any welds that have already been cut out for defects or for any reason, May
also require destructive testing.
 The mechanical destructive testing shall be performed by Aneri Construction at no extra
cost to GGL. If the mechanical test results are unsatisfactory, one more weld shall be cut
adjacent to that of previously removed production test joint or the joint welded on the
same day. If the second test coupon also gives unsatisfactory results then the welding
operation shall be suspended and may not be restarted until such failure causes have
been identified and Aneri Construction guarantee to prevent reoccurrence. If the second
test coupon is giving satisfactory results this assures mainline welding as per the
approved WPS.
 The weld joints represented by the unsatisfactory produced mechanically tested welds
shall stand rejected unless the investigations prove otherwise.
 Welder’s performance report shall be submitted to GGL / TPIA on weekly / monthly basis.
10% repairs shall be considered for rejection and 5-10% repairs shall be considered for
alarming for rejection.

4 Welding Repairs:
 Welds, which do not comply with the standards of acceptability, shall be repaired or the
joint cut out and re-welded.

6 OF7 Procedure for Welding

 Procedure of
Production welding
ACPL


A Separate welding procedure with welders’ qualification (as per API1104 and GGL/TPIA
approved) shall be required to be produces before taking repairing jobs.
 Repair will be done with SMAW process by a single welder as per the WPS.
 With respect of radiography or other NDT method, repair location will be marked on the
weld to reference points on film with tracing paper.
4.1 Method of Repair
 Partial Repair: Each layer will be thoroughly checked for this type of discontinuity
predicted NDT reports. Smooth grinding will be done to make “V” groove and clean all
surfaces. This is limited to 30% of weld length only.
 Through Repair: Grinding will be done up to root and root opening will be done by chisel,
hacksaw blade. The entire repair portion will be ground smoothly to “V” groove, to attain
root of sufficient gap as per WPS. Minimum repair length to be 100 mm as measured over
recap length. Limiting the root repair to only 20% of weld length.
 The welded joint to be repair in the preheated to the extent of 50mm on either side of
weld using Propane hand held torch up to 1000 C.
4.2 Welding:
 After identifying the defects, grinding shall be done to remove the defects. Care shall be
taken to ensure that no grinding marks on pipe surface anywhere. DPT examination shall
be done to ensure the removal of defect. Root sealing or single pass repair deposit shall
not be permitted. Internal root defects shall be ground thoroughly and welded with a
minimum of two passes as per qualified procedure. The edge preparation shall be smooth
free form burrs, cuts and other surface irregularities. The root gap shall be made carefully
 The welded area shall be thoroughly cleaned. Repairs opening the root shall be carried
out in the presence of the GGL/TPIA. All repairs shall be carried out during the day after
initial radiography of as early possible
 The reports of the all repairs shall be maintained by the Aneri Construction and shall be
submitted to the GGL/TPIA
 Each pass will be thoroughly cleaned using Power brush / Grinder
 The repair shall be subjected, as a minimum requirement to the same testing and
inspection requirements as the original weld. The entire joint shall be re-radiographed. A
100% ultrasonic test shall be done at the repaired area externally. Any repaired area that
is wide, irregular or rough shall be rejected and a full cut out shall be done.
 Only one attempt at repair of any region is permitted and no re repairs will be acceptable.
5 Documentation
 Inspection Report
 Inspection Test Plan

7 OF7 Procedure for Welding