SELATO | Retrofit of a welding machine for SCHÄFER SUDEX

Welding Machine Retrofit

SCHÄFER SUDEX, based in Ledeč nad Sázavou, is a long-established manufacturer of stainless steel barrels, pressure vessels, and containers. For many years, the company had been using a German-made welding machine dating from 1997. The machine had operated reliably for nearly 30 years but had reached the end of its service life. Both mechanically and electrically. The scope of our contract was the complete overhaul and modernization of a circular welding machine designed for welding individual barrel components. However, the customer gained much more than just an overhaul. Our delivery, completed in the last quarter of 2025, included:

Complete disassembly and renovation of the machine’s mechanical components,
Complete replacement of the electrical wiring and control components,
Retention of functional pneumatic cylinders and sensors
Implementation of a modern control system,
Addition of safety signage and fencing,
Replacement and optimization of control element placement as requested,
Preparation of documentation in accordance with applicable legislation (CE marking, risk assessment, user manual).

The main benefits of the refurbishment for the customer that we have achieved include, above all, extending the service life of key production equipment by several years, increasing productivity through automated operation, improving workplace safety and ensuring compliance with regulations, securing the availability of spare parts, and providing a service partner for future maintenance.

Technology upgrades, key improvements, and regulatory compliance

CONDITION OF THE MACHINE BEFORE RETROFIT
CONDITION OF THE MACHINE AFTER RETROFIT

ORIGINAL CABINET
NEW CABINET

OLD CONTROLS
NEW CONTROLS

Retrofit as an opportunity for innovation
This project was not just about modernizing an old machine and bringing it into compliance with current regulations. We take that for granted. Our goal was to listen to the customer and the machine operators. To identify imperfections and weaknesses in terms of the machine’s ergonomic controls and try to eliminate them. And even though it’s not always the case that machine operators welcome changes, in this instance, thanks to the collaboration of an experienced team, we managed to create a solution that genuinely simplified and improved the customer’s work.
Petr Ambrož
Project Manager, SELATO

IMPROVED ERGONOMICS, OPERATOR COMFORT, AND PRODUCTIVITY

Based on feedback from production staff, we have addressed the following issues: relocating the wire feeder to an ergonomic height, and modifying the conveyor to support the product across its entire length without the need for additional makeshift supports. We also focused on clearer machine control and diagnostics via a mobile operator panel and the placement of controls according to operator requirements.

AUTOMATION OF THE WELDING PROCESS

We added a communication card to the welder and created welding programs (so-called “jobs”) that enable manual mode for single-piece production and automatic mode for serial production (e.g., 20 barrels in a row without operator intervention). This significantly increased productivity and reduced dependence on the constant presence of a welder.

COMPLIANCE WITH LEGISLATION AND SAFETY

After the overhaul, the machine was provided with a new CE marking, complete technical documentation, and a risk assessment in accordance with applicable legislation. The customer thus received not only a modernized machine but also equipment that is fully compliant with legislation, complete with a warranty and service support.

The Project’s Biggest Challenges

The project presented several technical and organizational challenges:

Handling a 3-ton piece of equipment during transport to and from the workshop.
Manufacturing a special adapter between the new servo drive and the transmission for the original transmission. It was necessary to produce a custom-made adapter.
KCommunication with the customer’s welding machine, which was not standardly prepared for integration into an automated system.

All these issues were successfully resolved in collaboration with the design team, the customer, and the suppliers. The customer was actively involved in the project even during the overhaul. They participated in key testing milestones at our workshop. We encountered no unpleasant surprises during commissioning or handover. The handover included a pre-acceptance inspection of the welding at the workshop, on-site installation, operator training, and assistance during the first days of operation. The total renovation time was approximately 2 months.

A reliable machine, more user-friendly operation, expanded functionality
The retrofit of the welding equipment exceeded our expectations. Not only did we receive a reliable machine built with modern components, but we also gained significantly more user-friendly operation and the ability to perform automatic batch welding. We appreciate the professional approach of the entire team, their ongoing communication, and their support during the machine’s commissioning. Based on this positive experience, we plan to refurbish additional equipment and are definitely looking forward to working with the SELATO team on this.
Luboš Cihlář
Welding Technologist, SCHÄFER SUDEX