Hoang Tam - Installation of CARBON STEEL CONSTRUCTION FRAME, HOPPER & BAG TIPPING for GPJP KAJIMA JAPAN Project of Partner GEA NEW ZEALAND LTD 12/2021 has affirmed our capacity as a general contractor for auxiliary mechanical fabrication and industrial installation on the map of international standard FDI projects. The project required close coordination between European technology design from GEA New Zealand, the rigorous quality and safety management processes of the main contractor Kajima Japan, and the practical execution capabilities on-site of the skilled engineering and welding team from Hoang Tam.
Background and Importance of the GPJP Kajima Japan Project
December 2021 was a highly challenging period for the global supply chain in general and the industrial construction industry in Vietnam in particular due to the impacts of pandemic prevention measures. In this context, the GPJP project, with the leading Japanese construction corporation Kajima as the general contractor, combined with the world's leading provider of food and dairy processing technology solutions - GEA New Zealand Ltd, demanded an extremely strict construction schedule.
The installation of the Carbon Steel Construction Frame, Hopper, and Bag Tipping station were core modules in the factory's dry powder raw material handling line. Any delay or technical error in this segment would have a cascading effect on downstream stainless steel sanitary storage tanks, process piping systems, and packaging equipment.
Hoang Tam participated in the project not only as a precision mechanical fabrication unit but also took responsibility for site project management, implementing installation methods that simultaneously met two high-end technical standards: Japanese Industrial Standards (JIS) for structures and European hygienic and technological safety standards (GEA Standards).
Detailed Carbon Steel Construction Frame Category
Material Requirements and Mill Test Certificates (MTC)
The support frame system in this project is subjected to very large dynamic loads from raw material dumping operations, vibrations from dust shaking motors, and the vibration mechanism supporting discharge from the Hopper. Therefore, Hoang Tam used carbon structural steel grade SS400 or SM490 according to JIS G3101/G3106 standards, complete with CO/CQ and quality inspection certificates from reputable steel mills.
Each batch of steel arriving at the workshop underwent strict inspections for geometric dimensions, flatness, straightness, and actual thickness before entering the high-power CNC plasma or laser cutting phase. Tight control of input materials minimized warping or residual stress during structural welding.
Fabrication Technology and Heavy Plate Structural Welding at the Workshop
All columns, main beams, secondary beams, and connection gusset plates of the Carbon Steel Construction Frame were fabricated at Hoang Tam's workshop in Le Minh Xuan Industrial Park before being transported to the site. The welding process was executed in accordance with AWS D1.1 standards by pressure welders holding international 3G and 4G certifications.
- Beveling preparation: Steel plates with thicknesses from 12mm to 25mm were beveled in V or K shapes using specialized beveling machines to ensure maximum weld penetration.
- MIG/MAG welding technology: Using mixed shielding gas (Ar + CO2) stabilizes the arc, reduces spatter, and yields a smooth weld surface with outstanding tensile and tear strength properties.
- Non-Destructive Testing (NDT): 100% of the main load-bearing welds were inspected using ultrasonic testing (UT) and liquid penetrant testing (PT) to detect early internal defects such as cracks, porosity, or slag inclusion.
Surface Treatment and Anti-Corrosion Protective Coating System
The operating environment of a food processing plant demands strict cleanliness and resistance to cleaning chemicals. Therefore, the carbon steel frames, after being abrasive blasted to Sa 2.5 standard, were coated with a premium 3-layer epoxy system:
- Zinc-rich primer with a thickness of 60 micrometers for electrochemical corrosion protection.
- Epoxy micaceous iron oxide (MIO) intermediate coat with a thickness of 100 micrometers to enhance mechanical barrier protection.
- Polyurethane (PU) topcoat in industrial gray with a thickness of 50 micrometers for UV resistance and chemical protection.
Dry film thickness (DFT) was measured and recorded using specialized gauges, ensuring a total paint thickness of at least 210 micrometers, which meets the harsh operating standard of over 10 years without peeling or rusting underneath.
Design and Fabrication of the Hopper & Bag Tipping System
High-Performance Hopper (Intermediate Holding Vessel)
Unlike the carbon steel support frame, the Hopper vessel directly contacts the powder raw material, so it was fabricated entirely of SUS304 stainless steel with a thickness of 3mm to 5mm. Fabricating the Hopper required extremely high geometric precision to ensure the hopper's slope angle (typically 60 to 70 degrees) optimized powder flow, avoiding bridging or ratholing.
The inner surface of the Hopper was mechanically polished to a roughness of Ra < 0.8 micrometers, followed by chemical passivation using a specialized acid solution according to ASTM A380 standards to rebuild the protective chromium oxide film, completely preventing fine powder adhesion and microbial corrosion.
Bag Tipping Station with Integrated Dust Collection System
The Bag Tipping system fabricated and installed by Hoang Tam is an optimal solution to streamline operators' manual tasks when loading raw materials from 25kg bags. The station's design includes:
- Bag support grate (Grating): Made of heavy-duty SUS304 stainless steel, easily removable for periodic cleaning.
- Protective flap door with integrated pneumatic dampers: Enables smooth, safe operation for operators while containing dust within the enclosure.
- Active dust collection hood: Directly connected to the factory's central dust extraction system, creating slight negative pressure inside the tipping chamber to prevent all fine dust from escaping into the production area.
- Magnetic Grate Separator: Installed at the bottom of the tipping station to thoroughly remove metal contaminants from the incoming raw material before it enters the Hopper system.
Non-Metallic Connection Solutions to Prevent Vibration Transmission
To prevent vibrations from pneumatic hammers mounted on the Hopper from transferring to the main carbon steel support structure, Hoang Tam applied a flexible connection solution using FDA-compliant food-grade silicone gaskets. These flexible joints ensure absolute tightness for both compressed air and fine powder while effectively dampening mechanical vibrations, thereby extending the service life of the support frame's bolted connections.
Installation Process on the GPJP Kajima Japan Site
Site Preparation, Surveying, and Alignment
Surveying plays a decisive role in the success of multi-tier steel structure installation. Hoang Tam's engineers utilized high-precision total stations and laser levelers to align centerlines, axis marks, and elevations of anchor bolts pre-cast into the concrete slab handed over by the main contractor Kajima.
Any deviations in anchor bolt alignment exceeding the allowable tolerance (+/- 2mm) were recorded, reported, and promptly rectified using specialized shimming methods prior to hoisting the first steel column.
Safe Steel Structure Hoisting Process
Since the construction area was inside a workshop with partially completed roof and walls, the use of large mobile cranes was restricted due to tight spaces. Hoang Tam's engineering team developed a detailed lifting plan combining specialized forklifts, mini crawler cranes, and chain hoists mounted on temporary beams.
The lifting process for each column and beam of the Carbon Steel Construction Frame was carried out in a strict sequence:
- Inspect loads, rigging cables, lifting chains, and lifting lugs that had been load-tested at the workshop.
2. Perform a trial lift of 100mm off the ground to inspect the balance and braking system of the lifting equipment.
3. Move the component into position and temporarily secure it using alignment bolts.
4. Adjust the verticality of the columns using specialized plumb bobs and spirit levels.
5. Tighten high-strength bolts (Grade 8.8, 10.9) to design torque using periodically calibrated torque wrenches. Record torque tightening logs for each frame node.
Installing the Hopper and Bag Tipping Mechanisms into the Support Frame
Once the carbon steel frame was accepted for load capacity and geometric tolerances, the stainless steel Hopper and Bag Tipping equipment were lowered into position from the upper levels using soft webbing slings.
Due to the different thermal expansion coefficients and the risk of galvanic corrosion between carbon steel and stainless steel, Hoang Tam inserted 5mm-thick insulating gaskets made of engineering plastic (POM or Teflon/PTFE) along with insulating bolt sleeves at direct contact points between the Hopper flanges (stainless steel) and the frame beams (carbon steel). This technical solution completely prevents galvanic corrosion at the connection points.
Quality Control (QA/QC) and Occupational Safety under Japanese Standards
Rigorous QA/QC Quality Management System
Throughout the process from workshop fabrication to final site installation at the GPJP project, Hoang Tam applied an integrated quality control workflow combining our ISO 9001:2015 system with strict acceptance checklists from GEA New Zealand and Kajima Japan.
The project's as-built documentation contains complete and transparent technical records:
- Material Test Reports (MTR/Mill certificates) for carbon steel, stainless steel, electrodes, welding wire, and bolts.
- Non-Destructive Testing (NDT) reports using UT and PT methods conducted by an independent Level-3 third-party inspection agency.
- Calibration certificates for all measuring equipment used on-site (total stations, torque wrenches, paint thickness gauges).
- Powder coating/epoxy painting logs and inner surface roughness measurement reports for the Hopper.
- Static Commissioning reports confirming eccentricity, height, and flatness tolerances achieved within 1mm.
Absolute Occupational Safety Standards of General Contractor Kajima
Working on the site of one of Japan's largest construction general contractors like Kajima requires the highest level of discipline and safety management. Hoang Tam's personnel strictly adhered to the following principles:
- Daily Morning Toolbox Meetings: Briefing tasks and performing hazard identification (KYT - Kiken Yochi Training) before every shift.
- Permit to Work (PTW): All high-risk activities, such as Working at Height, Hot Work (welding/cutting), and heavy lifting, required approved permits from Kajima and GEA safety supervisors prior to execution.
- Standardized Personal Protective Equipment (PPE): Steel-toe boots, safety helmets with Y-straps, safety glasses, cut-resistant gloves, and double-lanyard full-body safety harnesses with shock absorbers when working at heights of 2 meters or more.
- Fire and Explosion Prevention: All cutting and welding areas on-site were enclosed with specialized fire blankets, equipped with portable CO2/dry powder fire extinguishers, and monitored 100% of the time by designated fire watches.
Real-world Challenges and Overcoming Difficulties by Hoang Tam
Overcoming Supply Chain Barriers Caused by the Pandemic
In December 2021, the global supply chain was severely disrupted. Certain specialized components for the Bag Tipping system, such as FDA-compliant food-grade silicone gaskets and rotary valves, were at risk of import delays from Europe.
Thanks to an extensive network of partners and years of built reputation, Hoang Tam's procurement department quickly sourced and proposed alternative material solutions available within Southeast Asia or from authorized distributors in Vietnam. These were committed to delivering equivalent technical specifications and were fast-tracked for approval by GEA New Zealand engineers within 48 hours, keeping the overall project schedule on track.
Execution in Confined Spaces and High-Altitude Working Conditions
The Carbon Steel Construction Frame featured significant tier heights, a narrow floor area, and was surrounded by numerous existing process piping systems in the factory. Installing steel beam components weighing several tons demanded high dexterity and smooth coordination between lifting equipment operators and assemblers on scaffolding.
Hoang Tam applied a solution of pre-assembling the frame into semi-finished modules at the Le Minh Xuan fabrication workshop, then transporting them to the site for bolted connection assembly rather than welding directly at height. This method improved weld quality under workshop conditions and minimized high-risk works at height, shortening the actual erection schedule by 25%.
Sustainable Value Delivered to Partner GEA New Zealand Ltd and the GPJP Project
The on-time completion, outstanding quality, and absolute safety of the Carbon Steel Construction Frame, Hopper & Bag Tipping installation package in December 2021 consolidated the long-term strategic partnership between Hoang Tam and the GEA New Zealand Ltd technology group.
The equipment fabricated and installed by Hoang Tam operates stably, with zero technical issues or raw material leakage throughout wet commissioning and commercial production handover. Hoang Tam's ability to precisely integrate load-bearing carbon steel structural frames with sanitary food-grade stainless steel equipment has proven the competitive capacity of Vietnamese engineering brands in heavy industrial projects with the most stringent requirements from Japan and Europe.
Hoang Tam - A Trusted Partner in Industrial Equipment Fabrication and Installation
With a journey of many years of development, Hoang Tam is proud to be a pioneer in Vietnam, providing comprehensive solutions from consulting, design, and fabrication to installation and maintenance of stainless steel equipment for key industries: Food, Pharmaceuticals, Chemicals, and large-scale industrial storage tank systems.
We own a large-scale workshop equipped with modern machinery such as large-format fiber laser cutters, CNC hydraulic plate rolling machines, automatic welding robots, and an international-standard quality management system. Our team of engineers with extensive field experience on major sites is always ready to deliver technical solutions that optimize costs while exceeding quality expectations.
For any technical inquiries, custom solution design, or service quotations for mechanical fabrication and installation, please contact Hoang Tam using the detailed information below to receive the most professional assistance.
Detailed Contact Information
Hoang Tam
Office & Factory Address: Lot L1, Street No. 8, Le Minh Xuan Industrial Park, Tan Nhut Commune, Ho Chi Minh City, Vietnam
Technical Support Hotline: +84933049069
Project Department Phone: +84933049069
Email: contact@hoangtamsse.com
Official Website: hoangtamsse.com
