Welding Techniques for Pressure Vessels: What We Use and Why
Welding Techniques for Pressure Vessels: What We Use and Why
The quality of a pressure vessel is largely determined by the welding technique used.
Every day, we manufacture pressure vessels for strategic sectors such as industry, compressed air, air treatment, chemical and petrochemical applications, as well as Energy & Power and hydrogen-related projects.
Our technical expertise, combined with deep knowledge of materials and industrial welding processes, allows us to choose and apply the most effective welding techniques based on each product’s specifications.
From design to production, we manage every phase in-house—including the welding systems developed at our facilities to ensure high performance, safety, and reliability.
In this article, we explain which welding techniques we use for our pressure vessels and when we use them.
Main Welding Techniques for Pressure Vessels
In our production process, we mainly use two welding techniques for pressure vessel construction: MIG (wire feed) and SAW (Submerged Arc Welding).
Both ensure high-quality welded joints and comply with the strictest international standards, including the SPVD and PED directives in Europe and the ASME code in the United States.
Let’s look at each in detail.
MIG Welding (Wire Feed Process)
The MIG/MAG (Metal Inert Gas / Metal Active Gas) welding method uses a continuously fed metal wire that melts to create the weld bead. The molten pool is shielded by an inert or active gas, preventing oxidation and enabling clean, high-quality full-penetration welds.
At Baglioni, we primarily use MIG/MAG welding for small-sized pressure vessels with thin walls, generally up to 100 liters in capacity.
This process ensures reliable joints and high productivity—crucial for series production lines.
SAW Welding (Submerged Arc Welding)
Submerged Arc Welding (SAW) involves an electric arc hidden beneath a granular flux, which protects the molten pool from oxidation and assists in the fusion of the material.
This process ensures full penetration, forming robust, continuous, and defect-free welds.
We use SAW welding for larger pressure vessels with thicker walls.
Specifically, we apply it to primary welds—both longitudinal and circumferential—on vessels ranging from 100 to 10,000 liters in capacity.
MIG/MAG vs. SAW: Differences and Selection Criteria
The choice of industrial welding technique depends on several factors, carefully assessed for each project. Key criteria include:
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Tank size
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Material thickness
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Component type
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Required productivity level
When Tank Size Matters
Tank size plays a crucial role.
MIG/MAG welding is ideal for small tanks up to 100 liters, thanks to its speed and ability to deliver clean joints quickly.
For larger volumes, SAW welding ensures continuity and deep penetration over long seams—making it the best option for medium to large tanks.
The Relationship Between Thickness and Welding Type
The welding process also varies by material thickness.
MIG/MAG is best for thin materials, as it minimizes impurity risk and enables fast, precise work.
SAW, on the other hand, is built for thicker materials, offering strong, high-deposition, long-lasting welds.
Accessory Components or Structural Joints?
For accessory components like legs, bases, and nozzles, MIG/MAG is the optimal solution—especially when integrated into automatic systems.
For primary welds (longitudinal or circumferential), SAW offers superior strength and reliability, particularly in pressure vessel applications.
Productivity: Flexibility or Large-Scale Output?
Production line setup is also decisive.
MIG/MAG offers maximum flexibility, suitable for both manual work on small batches and automated production.
SAW delivers peak performance on automated lines where operational continuity and high-volume output are required.
Baglioni’s Welding R&D: Innovation in Action
Our extensive experience in the field has never held us back from looking forward. In fact, we believe that only through constant innovation can we maintain high quality standards and effectively respond to evolving market demands.
That’s why Baglioni combines production with a structured research and development program aimed at continually improving our industrial welding processes.
We collaborate with technical institutes and technology partners to explore advanced solutions.
We assess the introduction of new methods and continuously test technical updates to boost line efficiency, shorten processing times, and enhance the quality of welded joints.
We also invest in automated welding technologies, the in-house design of our production lines, and employee training.
Because for us, innovation isn’t just about machines—it’s about people, skills, and the entire production system.
Want to learn more?
Read about Baglioni’s training initiatives: Training Young Talent in Industry: The Baglioni & Boniardi&Partners Partnership
Our mission is to stay ahead of change, test effective solutions, and turn every technical advancement into real value for our clients.
That means faster lead times and more reliable pressure vessels. For us, improving means never settling.
Speak with our technical team to find out which pressure vessel is right for your needs. Contact us!
