Extra Thick Weld Procedure – Chevron Australia

Marking one of the company’s thickest weld procedures to date, GF Engineering was engaged by Chevron Australia to perform a tough task.

Taking five weeks to fabricate, run and test the weld procedure , this signalled a rare project in the GF Engineering portfolio – one that GF Engineering Managing Director Todd Jones labelled as something that was “Pretty rare to see in our field and most people in our local industry won’t see at all.”

“We sourced a 24” 1500# A350 gr LF2 blind flange (224mm thick) and had to mill it down to 140mm to be able to water jet cut our coupon size and then mill it down again to 120mm thickness,” Project Manager Gabriel Bangera said.

An 18” 1500# spectacle blind (203mm thick) was utilised for the A516 gr70 material – as a plate at this thickness isn’t easily available to acquire in Australia. This also had to be milled down to 120mm thickness.

Taken on by long-term welder Vinnie, the challenge was set to weld the coupon completely with ‘stick’ and took two weeks to physically weld out.

The purpose of this procedure was to, ultimately, enable the client to navigate and avoid trouble on-site by providing a large range PQR that they could generate weld procedures from to suit their specific requirement.

A breakdown of the procedure:

Material: A516 gr 70 to A350 gr LF2
Length: 600mm
Thickness: 120mm
Bevel: 40 degrees
Process: All SMAW vertical up
Runs: 482x
Consumable: Over 3000x rods went in
Test piece weight: 500kgs upon completion

Testing results show UT, macro, tensile, bends, hardness & impact testing all passed.

Check out the photos of this great project below: 

Rotary Classifier – Alcoa Kwinana

As far as recent contracts go, GF Engineering’s track record of high-quality, industry-recognised projects was further solidified with its completion of the task to fabricate 2x rotary classifiers.

GF Engineering was awarded the project in September 2020. Work began immediately – the team got straight to work procuring the required plate/materials and began fabrication in early October.

The task, which was awarded to GF Engineering by Alcoa Kwinana, involved the fabrication of a rotary classifier. This involved a rotary outer can, rotary liner and bucket-wheel excavator – complete with flights. 2x of these assemblies were required.

No small task, the bucket-wheel measured 3380mm (outside diameter – OD), and shell 2460mm OD. Overall – 6735mm long. The weight – overall – totalled 19500kgs.

The refinery, which has operations spanning approximately 1,500-hectares of the Kwinana Industrial Area, contracted GF Engineering to complete the task due to our past history of fabricating these difficult items successfully and issue free.

“We always get excited when we have the opportunity to fabricate these items,” GF Engineering Managing Director Todd Jones said.

“It is a great project for our apprentice boilermakers and welders to be a part of as they learn many different aspects of how to fabricate correctly and accurately along the way.” Similar to the functionality of a cement mixer – the project formed a crucial part of the separation process with which the internal spirals separated the bauxite (mud slurry) from the process liquor which contains the alumina.

GF Engineering were able to undertake the entire fabrication including the machining of the tyres (where it sits on rollers onsite) in-house at its Naval Base site in WA.
The entire project was verified by third party surveying.

Bisalloy Protection 400/Hardox 450 Steel Materials (a quenched and tempered steel plate that is especially known for stellar wear resistance and impact toughness), were sourced and supplied by an additional third party company. Following its arrival at GF, the material was cut to appropriate size, and was then rolled into cans and welded. Spiral plates were marked up and cut and the difficult & methodical process of putting them altogether began.

“We always have a challenge of getting the variable pitch flights cut to the correct profile to suit the ID of the liner based on drawings from the 1980’s,” GF Engineering Project Manager Dan Williams said.

“However, with advancements in modern technology the challenge was easily overcome with our in-house drafting department creating a 3D model & organising a scaled model cut and fabricated to ensure accurate fitment. As technical as the project sounds we fabricated a spiral on a spiral, in a can, in a can.”

Demanding a high level of technicality, GF Engineering finished the project in early April 2021.