Duties of a welding inspector



ensure that all operations are carried out in complete compliance with local, company, or national safety legislation (i.e. permits to work are in place)


Check specification (Year and revisions)

Check Drawing (correct revision)

Check welding procedure specification and welder approval

Validate certificate of calibration (welding equipment & inspection instrument)

Check material and consumable certification

Welding process and ancillaries:

Check welding equipment and all related ancillaries (cable, regulator, oven, quiver etc).

Incoming Consumables:

Check pipe / plate and welding consumable for size, condition, specification & storage.

Marking out preparation & set up:

Check the:

Correct method of cutting weld preparation (pre-heat for thermal cutting if applicable).

Correct preparation (Relevant bevel angles, root face, root gap, root radius, land etc.)

Check pre-welding distortion control (Tackling, bridging, jigs, line up clamp, etc)

Correct level & method of pre heat applied prior to tack welding.

All tack welding to be monitored and inspected.




Whether conditions (Mainly for site work, welding is generally halted when inclement)

Pre-heat values (Heating method, location and control method)

In-process distortion control (Sequence or balanced welding)

Consumable control (Specification, size, condition, and any special treatments)

Welding process and all related variable parameter (Voltage, ampere, travel speed, etc)

Welding and/or purging gasses (Type, pressure/flow and control method)

Welding conditions for root run / hot pass and all subsequent run, and inter-run cleaning.

Minimum and/or maximum inter-pass temperatures (Temperature and control method)

Check Compliance with all other variables stated on the approved welding procedure




Carry out visual inspection of the welded joint (Including dimensional aspect)

Check and monitor NDT requirement (Method, qualification of operator, execution)

Identify repairs from assessment of visual or NDT reports.

Post Weld Heat Treatment (PWHT) (Heating method and temperature recording system)

Re-inspect with NDT/NDE after PWHT (if applicable)

Hydrostatic test procedure



Excavation procedure (Approval and execution)

Approval of the NDT procedures (For assessment of complete defect removal)

Repair procedure (approval of re-welding procedures and welder approval)

Execution of approved re-welding procedure (Compliance with repair procedure)

Re-inspect the repair area with visual inspection and approved NDT method


6 Responses

  1. i like ur website. please i would like to know the procedure for peaking and bending.

    Thank you.

    • Thanks Sam,..

      Peaking procedure:
      1. Prepare a horizontal weep board 900 mm long. The sweep board shall made to the nominal radius of the tank.
      2. Take a sample of vertical joint at least 4 point.
      3. Measure the deviations using a taper gauge.
      4. Deviations at vertical weld joint shall not exceed 13 mm

      Banding procedure:
      1. Prepare a a straight edge vertical sweep board 900 mm.
      2. Take a sample of horizontal joint at least 4 point.
      3. Measure the deviations using a taper gauge.
      4. Deviations at vertical weld joint shall not exceed 13 mm

      • Very happy when I know ur website.
        I have problem with banding inspection follow API 650, in this case. I always inspected fit-up and plumbness shell plates before welding, after welding, have local deviation, When I inspected, the banding between course 5th & 6th of tank is ok (lower 13mm), but the plumbness between of these course was not meet requirement follow API 650. what should I do (accept or reject) and explain for me.

  2. Dear Lakin.

    Of course you must reject because it’s does not meet the minimum requirement of API 650 and the construction should repair it.

  3. How many radiography shots required on long seams and circ. seams for a tank about 20′ dia and 28′ height

  4. visual examinaction procedure API 650 Required

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