On Wednesday October 14, voestAlpine Böhler Welding’s global product manager for full welding solutions, Francesco Ciccomascolo, presented the company’s new pipeline welding solutions, which are soon to be rolled out across Africa and the Middle East. African Fusion reports.
Click to download and read pdf
In the pipeline industry, perfect pipeline girth welds with consistent mechanical properties paired with high productivity and low repair rates are key priorities. Böhler Welding’s latest GMAW/FCAW orbital welding solutions, which guarantee repeatable high quality welds with reduced downtime, can bring these benefits to cost-sensitive pipeline contractors, begins Ciccomascolo.
The new solutions minimise repair rates, thanks to the fine-tuning of the high quality diamondspark flux cored wires; the manipulation and wire feeding precision offered by Böhler Welding’s pipeRunner orbital welding system; and the stable electric arc performance of the TERRA 400 PRM welding power source.
Ciccomascolo says that Böhler Welding’s full welding solution is, for example, ideal for pipeline contractors that want to introduce mechanisation in their welding process within a limited budget. Key benefits of the solution include easy installation and user friendly operation, while narrow gap preparations, site bevelling machines and internal pipe clamping systems are all unnecessary.
Manual root and hot pass: mechanised fill and cap runs
At the start of the solution is the use of the TERRA 400 PRM power source for manually welding the root and hot pass. This can be done with SMAW electrodes or by completing a manual GTAW root. Once these two passes are completed, however, the flux-cored process is used for the fill and cap weld passes, which are laid down using Bohler’s pipeRunner orbital bug and the diamondspark range of flux-cored wires for pipeline welding.
Trial welds on Grade API 5L X 70 pipe with a diameter of 910 mm and a wall thickness of 15,0 mm were successfully completed with five layers. The root consumable used was the FOX CEL (E6010), Bohler’s cellulose electrode designed for vertical-down welding of pipelines. This electrode is especially recommended for root run welding and offers good deposition efficiency and speed economy, particularly when compared to vertical-up welding. It also offers excellent gap bridging characteristics, and outstanding impact strength values.
The hot pass was completed using SMAW, using the FOX CEL 80-P (E8010-P1).This cellulosic electrode meets the strength requirement of the API 5L X70 pipe and was designed for vertical-down welding of high strength pipeline materials.
For the fill and capping passes, the diamonspark X70 RC-Pipe (E91T1-K2M-JH4) consumable was used with the weld metal being deposited using a pipeRunner moving vertically up from the 6:00 o’clock to 12:00 o’clock positions in the clockwise and counter clockwise directions of the pipe. A seamless rutile nickel-manganese alloyed flux-cored wire, the X70 RC-Pipe is the perfect match for this pipe material and also ideal for multilayer welding of carbon, carbon-manganese steels and high strength steels with Ar-CO2 shielding gas, typically M21.
Featuring excellent weldability in all positions and giving an excellent bead appearance with very low spatter losses, the slag produced is also fast freezing and easy to remove. The exceptional mechanical properties of this wire, particularly the low temperatures toughness values, and the low diffusible hydrogen content produced in the weld metal make this consumable especially suitable for pipeline applications.
This procedure enabled a defect-free, high quality joint with an excellent bead appearance to be completed in five layers with outstanding productivity results. Compared to a comparative joint completed using a full cellulosic SMAW procedure, the use of pipeRunner with the diamonspark flux-cored wire reduced arc time by 51% and total welding time, including fit-up, by 66%, while net savings in terms of the mass of the consumables deposited amounted to 46%.
Terra 400 PRM Pipeline
The Terra 400 PRM pipeline welding power source is a robust and reliable three-phase, new-generation, multi-process inverter designed to suit the needs of orbital pipeline welding while also capable of root and hot pass runs in manual or semi-automatic welding mode. The 400 PRM is equipped with a special display to manage all the welding processes involved, and an RC 100 MP remote control specifically designed for pipeline use.
The compact and robust design of Böhler Welding’s Terra welding machines makes it possible to use them in a variety of working environments, even in confined spaces. Suitable for MMA, dc TIG and GMAW/flux-cored processes, the machines deliver power in the 150 to 500 A range. The machines are built to cope with heavy loading and harsh environments while guaranteeing accurate and consistent welding parameters.
pipeRunner
Bohler Welding’s new pipeRunner is a programmable mechanised GMAW/FCAW orbital system designed for girth welding of pipelines and process piping. This is a state-of-the-art in-house Böhler Welding system that is designed from premium components, mostly manufactured in Germany and chosen to optimise system performance and reliability.
An intelligent intuitive and logical arrangement of all operating elements such as the welding torch, positioner, spool-holder, release lever, circumferential band, etc, makes setting up this system easy and quick. With all the electronics incorporated, the system still weighs only 14 kg, making pipeRunner one of the lightest welding bugs on the market. Modern dc brushless electric motors are used to ensure accurate and consistent travel speeds and high reliability, and the modular design approach lends itself to possible upgrades.
The system was designed with vertical up FCAW welding in mind, but vertical down welding using GMAW is also possible. The device can easily be switched between clockwise (CW) and counter clockwise (CCW) welding around the pipe and the user friendly and comprehensive remote control gives the operator access to all manipulation functions using one hand.
With respect to programming, proprietary software is already included, which is compatible with all standard PCs, and an optional heavy duty tablet is also available. Welding parameters and sequences for up to 11 different passes can be programmed.
In terms of ergonomics, optimised weight distribution makes the unit particularly easy to handle compared to conventional bugs. A 4-handle aluminium spaceframe makes for easy lifting, comfortable transportation and handling in any position. The adjustable welding torch is mounted on the upper part of the frame and the wire feed unit also works as an integrated pedestal on the opposite part of the frame, assuring a comfortable, stable operating position. The system comes with a high quality box and suitcase to make it easy to transport to and from the site.
diamondspark seamless flux cored wires
The seamless design of Bohler Welding’s diamondspark flux-cored wires ensures low diffusible hydrogen content with no moisture pick up during storage and handling, reducing the risk of hydrogen delayed cracking and wormholes. The diamondspark X RC Pipe product range is copper coated, which gives excellent current transfer and reduced contact tip wear. These wires are known for trouble-free feeding, which further increases arc time. The pipeline-optimised flux recipe guarantees a thick slag to support the molten weld pool when travelling up, but the slag is easily detached.
Pipeline-dedicated wire formulas further improve the weld metal mechanical properties, keeping high toughness while delivering high productivity. diamondspark X RC Pipes are suitable for sour service and, using the diamondspark X70 RC-Pipe (N), are NACE compliant up to the X70 Grades, which means they can be used for pipe materials exposed to H2S in oil and gas production environments.
For voestalpine Böhler Welding, being a full welding solutions provider means acting as a partner for pipeline contractors through the weldTECH Application Services, which include a team of welding engineers experienced in pipeline construction, Francesco Ciccomascolo concludes.
