Welding in the Food, Beverage & Dairy Industry

Why Does Weld Quality Matter in Food, Beverage, and Dairy Manufacturing?

The hygienic requirements of food, beverage, and dairy production place high demands on the welds that hold tanks, pipes, and vessels together. A poor-quality weld or surface finish isn't just a cosmetic issue; it's a contamination risk. Rough or porous welds can trap bacteria, and past contamination scares in the dairy sector are a reminder of how costly getting this wrong can be.

Every metre of weld inside a storage or process vessel represents risk that has to be actively managed. Fabricators need to control both weld integrity and surface finish to meet hygiene requirements. Not just at the point of welding, but throughout the design and cleaning process too.

What Welding Processes Are Used in Food, Beverage, and Dairy Manufacturing?

Food, beverage, and dairy manufacturing draws on several welding processes, each suited to a different part of the production line, from small-diameter pipework to large storage vessels to on-site repairs.

Which Process for Which Application?

Automatic Plasma Arc Welding (PAW) and Seam Welding: for Tanks and Vessels

Automated PAW equipment produces consistently high-quality welds with minimal heat input and no removal of parent material for preparation. Unlike TIG, which is susceptible to tungsten inclusions from the exposed electrode, PAW has no exposed electrode, significantly reducing the risk of inclusions in the weld. Butt welds up to 8mm thickness can be completed in a single pass with only a gas backing shield required, and weld reinforcement is minimised, helping achieve the smooth finish sanitary applications demand.

Automated seam welding delivers the highest quality sanitary finish for longitudinal tank seams, essential for food, beverage, dairy, and pharmaceutical clients. Reducing fabrication time and cost while producing a consistently smooth finish along the full weld length.

We have a range of new and used longitudinal seam welders for sale, available with plasma welding sources; explore our stock >

Orbital Welding: for Process Pipework

For stainless steel pipe runs carrying product between tanks, processing stages, and filling lines, orbital welding is the standard process. It produces smooth, fully penetrated welds with no crevices where bacteria can accumulate, and its controlled heat input avoids the carbon precipitation and corrosion resistance loss that can occur when stainless steel is overheated during manual welding. Because every joint on a run is completed to the same programmed parameters, orbital welding removes the weld-to-weld variability of manual TIG; important when a facility needs to demonstrate consistent weld quality for audit or compliance purposes.

For a full breakdown of how orbital welding works and where else it's used, see our Orbital Welding Guide, or explore our range of orbital welders in stock.

Circumferential and Rotary Welding: for Large Vessels

Not every vessel weld fits a small orbital tube-welding head. For larger-diameter shell-to-head joints, manway welds, and big nozzle welds on tanks and vessels, circumferential welding rotates the workpiece itself. Using a welding positioner, pipe rotator, or column & boom system, the torch stays fixed. This gives the same consistency benefits as orbital welding, but scaled up for vessel fabrication rather than pipe runs.

Manual TIG and MIG Welding: for Repairs and Structural Work

Automated and orbital processes cover most production welding; however, manual TIG welding still has a place for repair work, on-site modifications, and irregular joints like nozzles and manways that don't suit a programmed process. Most food, beverage, and dairy facilities keep manual TIG capability available even where the bulk of production welding is automated.

MIG welding, meanwhile, is typically not used for product-contact sanitary welds, but is common for the structural framework, supports, and brackets around processing equipment; the non-product-contact fabrication that still needs to happen on the same build.

Browse our range of new and used MIG welders and TIG welding machines.

How Is Surface Finish Measured for Sanitary Welds?

Surface roughness on internal weld seams (whether from PAW, seam welding, orbital, or circumferential welding) is specified in Ra; a measurable roughness value in micrometres obtained using an Ra meter. This is a more reliable specification than the older "grit" measurement, which described how coarse the polishing medium was rather than the finished result, meaning two operators polishing to the same "grit" could produce different actual roughness.

What Stainless Steel Grades Are Used in Food, Beverage, and Dairy Welding?

304 stainless steel is the standard choice for most food-contact equipment like tanks, pipework, and general processing surfaces, offering good corrosion resistance at a lower cost than higher grades. 316L stainless steel, with molybdenum added for improved resistance to chlorides and acidic products, is typically specified for higher-corrosion environments such as brine processing, high-salt products, or dairy applications where aggressive cleaning-in-place (CIP) chemicals are used regularly. The "L" (low carbon) variant is preferred for welded applications specifically, as it reduces the risk of carbide precipitation at the weld and heat-affected zone, which can compromise corrosion resistance exactly where it matters most.

How Is Automation Changing Welding in Food, Beverage, and Dairy Manufacturing?

Automation adoption in this sector has historically lagged behind other industries, partly due to its strict regulatory environment. That's changing as rising raw material and energy costs push manufacturers to seek efficiency gains, while automated welding systems are becoming more cost-competitive, offering a faster return on investment.

Automated welding and seam-welding systems bring several practical benefits to food, beverage, and dairy production:

When evaluating automation, most manufacturers weigh it against total cost of ownership (TCO), time to market (TTM), overall equipment effectiveness (OEE), and return on investment (ROI). The same framework is generally used across food, beverage, and dairy capital equipment decisions.

What Are the Principles of Hygienic Design for Food, Beverage, and Dairy Facilities?

Welding quality is only part of the picture. The way a facility and its equipment are designed also determines whether hygiene standards can be met in practice. Five key principles underpin hygienic design:

1. Barriers that prevent pathogens from entering the production area
2. Infrastructure that doesn't allow pathogen growth
3. Production systems that limit cross-contamination between processes
4. Effective cleaning and disinfection built into the design, not added afterwards
5. Monitoring and verification systems to confirm the above controls are working

Poor design is a common contributing factor to contamination risk, even in new-build facilities. Weak foundations, inadequate floor and drainage systems, and gaps between contractors (for example, flooring and drainage being installed without coordination) can all create crevices where pathogens like listeria can harbour. A crevice-free result depends on trades working together at the design stage, not just on weld quality after the fact.

What Welding Standards Apply to Food, Beverage, and Dairy Manufacturing?

Sanitary and hygienic welding standards, including EHEDG (European Hygienic Engineering & Design Group) guidance and equivalent frameworks, apply across food, beverage, dairy, and pharmaceutical manufacturing, not just to one industry. These standards cover weld surface finish, joint design, and material selection in detail.

FAQs

What welding processes are used in food, beverage, and dairy manufacturing?

The main processes are automatic plasma arc welding (PAW) and seam welding for tanks and vessels, orbital welding for small-diameter process pipework, circumferential/rotary welding for large vessel welds, and manual TIG for repairs and irregular joints.

What's the difference between orbital and circumferential welding?

Orbital welding rotates the welding head around a fixed pipe, typically used for smaller-diameter tube and pipe joints. Circumferential (rotary) welding rotates the workpiece itself on a positioner or pipe rotator while the torch remains fixed, used for larger-diameter vessel welds like shell-to-head joints and manways.

Why is stainless steel used for food, beverage, and dairy welding?

Stainless steel, typically grade 304 or 316L, offers strong corrosion resistance and can be finished to a smooth, cleanable surface — essential for equipment that comes into contact with food or drink products, including dairy processing lines exposed to frequent CIP cleaning.

What does "hygienic welding" actually mean?

Hygienic welding refers to producing welds with a smooth, crevice-free surface finish that won't harbour bacteria, using processes and techniques that avoid contamination risks such as tungsten inclusions or excessive heat input.

How is weld surface finish measured for sanitary applications?

Surface roughness is measured in Ra (a value in micrometres using an Ra meter), which gives a consistent, verifiable standard, unlike the older "grit" measurement, which varied depending on the operator and polishing medium.

Can automation improve hygiene in food, beverage, and dairy welding?

Yes. Automated welding systems remove operator-to-operator variation, producing more consistent weld quality. This is directly linked to hygiene compliance, alongside efficiency and cost benefits.