Fabrication & Welding Works

Fabrication and assembly of metal structures and pressure vessels, welding of pipes and equipment, and repair and maintenance of components.

Service features

• High quality
• Compliance with technical standards
• Pressure vessels designed, fabricated and certified under the applicable section of the ASME Code

In the oil and energy industry, welding is applied to pipelines, pressure vessels, metal structures and critical components. A formal welding service includes:

Why it matters: weld quality determines the integrity of the joint, which is why it is verified through inspection and documented.

The process is chosen according to the material, the thickness, the welding position and the quality the specification requires. The processes used are:

Work carried out in the shop and in the field:

• Spools and piping for process, fuel and utility lines
• Pressure vessels under the ASME Code
• Storage and process tanks
• Metal structures: pipe racks, walkways and stairs
• Huts in metal or fiberglass-reinforced plastic (FRP)
• Sampling trays
• Pumping and compression systems

A pressure vessel is a closed container that holds a fluid at a pressure different from the atmospheric one: separators, scrubbers, accumulators, air receivers, filters and the shells of heat exchangers. Because a failure releases the energy stored in it, its design, its materials, its welds and its tests follow a code.

Pressure vessels are designed, fabricated and certified under the applicable section of the ASME Boiler and Pressure Vessel Code.

1. Design

   Calculation of thicknesses, heads, nozzles and supports for the design pressure and temperature, with the corrosion allowance.

2. Materials

   Plates, forgings, pipe and fittings of the grades the code allows, with their certificates and traceability.

3. Fabrication

   Cutting, rolling and fit-up; welding with qualified procedures and qualified welders; heat treatment when the code requires it.

4. Examination

   Non-destructive examination of the welds to the extent the design requires.

5. Pressure test

   Hydrostatic test of the finished vessel, above its design pressure.

6. Certification

   Data report signed after the inspection, and nameplate with the design data of the vessel.

1. Review of drawings and specifications

   Review of the drawings, the specifications and the applicable standards, and definition of procedures and inspection points.

2. Material verification

   Receipt of material with its certificates and identification, so that every piece can be traced.

3. Cutting and fit-up

   Cutting, beveling and alignment of the parts, held in place with tack welds.

4. Welding

   Welding under the qualified procedure, by qualified welders, with control of the welding parameters.

5. Inspection and testing

   Visual inspection, non-destructive testing and, where applicable, pressure testing.

6. Finishing and documentation

   Dimensional check, cleaning and, when required, coating; final dossier with procedures, qualifications, inspection reports and traceability.

Weld quality is verified without damaging the part. The usual methods are:

Typical interventions on equipment that is already in service:

• Weld repair of cracks, wear and damaged joints
• Replacement of corroded or damaged sections of pipe and plate
• Reinforcement and modification of existing structures
• Rebuilding of worn components
• Re-inspection after the repair, with the same acceptance criteria as the original work

Reference standards commonly applied in the sector. They are listed for orientation and do not replace the specification of each project.

API 1104

Welding of pipelines and related facilities for fuels and petroleum products.

API 650

Welded tanks for oil storage.

AWS D1.1

Structural welding of carbon and low-alloy steel more than 3 mm thick.

ASME IX

Qualification of welding procedures and welders.

ASME B31.3 / B31.8

Process piping (B31.3) and gas transmission and distribution piping (B31.8).

ASME V

Methods and acceptance of non-destructive examination.

ASME VIII Div. 1

Rules for the construction of pressure vessels: design, fabrication, inspection, testing and certification.

ASME II

Materials for boilers and pressure vessels.