Welding contractors for industrial plants in Spain and Portugal

Welders on your site, or work to order

• Welders on your site: they work in your plant for as long as the job lasts and weld what they are given. This suits a shutdown, extra hands on a project or a peak in workload.
• Work to order: you define what has to be welded, whether an item of equipment, a pipe run or a structure, and we take the job on.

¿Cuántos soldadores podéis mandar a la vez, con qué antelación y quién los dirige en planta, el cliente o un responsable vuestro?

Welding processes: TIG, MIG and manual metal arc

We use three processes. Which one fits depends on the material, the thickness and where the weld is made.

• TIG (GTAW): tungsten electrode and shielding gas. It is the process for thin sections and for joints where finish and control of the filler matter, such as stainless pipework.
• MIG (GMAW): continuous wire and shielding gas. It deposits more metal per minute than TIG and suits thicker sections and long runs.
• Manual metal arc (MMA, also called stick): manual welding with a flux-coated electrode. It needs no gas bottle, so it copes better outdoors and in awkward access.

¿Qué espesores mínimo y máximo soldáis con cada proceso?

Coded welders: what to specify

In the UK, a coded welder is one who holds a current qualification certificate for a given process, material, thickness range and position, issued after a test to a recognised standard. In Europe the same idea is a welder qualification to EN ISO 9606, and the certificate belongs to the welder, not to the company.

If your job calls for coded welders in Spain or Portugal, say which standard applies, which process and material, and which thickness range and position. A test for TIG on stainless steel does not cover MIG on aluminium.

• What each welding certification covers

¿Los soldadores que ponéis en planta trabajan con ISO 9606 o con ASME IX, y puede el cliente pedir copia del certificado antes de la incorporación?

Stainless steel welding

Stainless steel resists corrosion because of a chromium oxide film on its surface. If the weld overheats, or picks up particles of carbon steel, the film is lost and rust appears where it should not.

That is why heat control and cleanliness count as much as the bead itself. On pipe and vessel joints the root side is normally purged with argon for the same reason.

¿Con qué calidades de inoxidable trabajáis (304, 316L, dúplex…)?

Aluminium welding

Aluminium carries heat away quickly and is covered by an oxide film that melts at over 2,000 °C, while the metal itself melts at about 660 °C. The film has to be cleaned off before welding, and the heat has to be metered so the part neither distorts nor burns through.

¿Qué aleaciones y espesores de aluminio soldáis?

Titanium welding

At high temperature titanium absorbs oxygen, nitrogen and hydrogen from the air and turns brittle. It is therefore welded under inert gas that shields the bead and the back of the joint until it has cooled.

¿Qué piezas o equipos de titanio habéis soldado?

Welding pipework and pressure vessels

Welding installed pipework and welding a pressure vessel each carry their own requirements. We cover them on their own pages.

• Industrial pipework: installation and pipe welding
• Pressure vessel fabrication and boilermaking

Welding procedures and testing

Where a job calls for qualified procedures, the welding procedure specification (WPS) sets out material, thickness range, process, filler, gas and parameters, and a procedure qualification record (WPQR) backs it with a test weld.

Pressure vessels, structural steelwork and process pipework usually also call for non-destructive testing of the welds, to a scope set by the applicable standard.

¿Tenéis procedimientos de soldeo cualificados (WPS) y qué ensayos no destructivos hacéis o subcontratáis?

What we need to quote

To send you a proposal we need the following.

• What has to be welded or, if you need welders, which profiles and how many people
• Material, thickness and welding process
• The standard that applies to the job
• Start date and duration
• Where the plant is
• What safety documentation or induction your site requires before anyone starts