Oerlikon solutions developed for the welding of cross country and off-shore pipelines.
The construction of pipelines involves different welding processes which choice depends from several factors, pipeline length, accessibility, pipeline organization etc….. .MMA process executed with cellulosic or LH electrodes, GMAW process in fully automatic configuration with orbital welding head single/multiple torches, FCAW process using multi-positional cored wires. SAW process is normally used in offshore pipeline to realize “off-line” longer pipe sections which are later joined together before laying on the sea. For each of this process Oerlikon can provide full range of consumables.
Oerlikon stick electrode range, includes several types for all the API steel grades used in pipeline. Cellulosic electrodes, FLEXAL, with grades from 6010 up to 9010, LH electrodes for vertical down welding, VERICORD 80 & 90, and classic LH electrodes for vertical-up welding.
Electrodes according to types are used for root pass in DCEP or EN and for filling and capping. Good compromise which combine productivity and mechanical properties is achieved using a mixed solution which consist in cellulosic electrode for root and hot pass and LH vertical down electrodes for filling and capping.
For GMAW automatic welding process, Oerlikon provides three wire grades with selected and well controlled chemical composition aimed to achieve the best features in both mechanical properties and weldability. CARBOPIPE 70, suggested for API steel grade up to X70, CARBOPIPE 80Ni, a Ni low alloyed wire for API X80 and CARBOFIL NiMo1 for higher grade steel, used also for X100 material. All wires are available in different packaging including the smallest one such us S100 plastic spool of 1,5 kg normally used for internal pipe welding.
Oerlikon owns a long tradition in producing flux cored wire in both seamless and folded technology. As alternative to solid wire we offer seamless metal cored wires always for vertical down-hill position; a solution which grant high welding speed and reduces the risks of lack of fusion. Seamless / folded wires with fast freezing slag are instead the right products for vertical up-hill position. Used with orbital welding equipment, they achieve good welding speed, reduce the number of passes for filling and requires less precise joint preparation than solid wire as well as less sophisticated equipment being the welding parameters regulation easier.
Among the different wires we may propose, we pull attention on seamless copper coated FLUXOFIL 14HD (E71T-1), FLUXOFIL 20 HD (E81T1-Ni1) and on folded types CITOFLUX R82 (E81T1-Ni1) suitable up to API X70. For higher grade steel CITOFLUX R550 (E91T1-G) & CITOFLUX R620 (E91T1-G) this one with Ni content limited to 1%. Typically, flux cored wire are used for filling the joint, which root and hot passes are realised in solid wire or electrodes.
Oerlikon’s agglomerated submerged arc welding fluxes, in combination with Oerlikon range of solid wires, have achieved worldwide recognition as the first choice for quality submerged arc welding. For double/multiple jointing used in off-shore construction, Oerlikon proposes two main fluxes, OP 121TT, a fully basic flux and OP 132 a semi-basic flux which allow higher welding speed along good slag detachability and mechanical properties.
These fluxes are used in combination with different wires according to steel properties, typically with OE-SD3 1Ni1/4Mo and OE-SD3 1Ni1/2Mo. The internal welding, generally realised in single pass, for achieving good toughness, requires the use of TiB alloying wires. Oerlikon satisfies this demand with OE-Tibor 33, OE-Tibor 22 and OE-Tibor 25, a TiB wire without Mo for better results in case of SSCC conditions.
For the execution of double jointing, Oerlikon provides a complete solution which include fixed or mobile based column and boom for external welding, boom (different lengths) for internal jointing, rotators, welding heads for single, twin, tandem and multi wires solutions and as generator the new STARMATIC 1200i AC/DC, an inverter power source with square weave technology. For pipe laying vessels we provide special equipment designed according to client needs.
Oerlikon products have been used for several projects. Some references: