Lehtosen Konepaja is again investing in the productivity of welding technology and is determined to invest in its machine base.
In heavy machinery manufacturing, highly automated solutions and welding robots increase the technological expertise required for demanding customer work.
For example, machine frame manufacturing typically consists of parts manufacturing, welding, heat treatment, machining and surface treatment.
In particular, our welding and surface treatment departments are top-notch and the main objective is still to increase the welding power and productivity. Our new acquisition is a submerged arc welding tower ESAB CaB 460 M, 7×5 M.

Submerged arc welding tower ESAB CaB 460 M, 7×5 M

The submerged arc welding tower ESAB CaB 460 M, 7×5 M multiplies production power, speeds up welding and improves the lead time of production. The submerged arc welding tower increases productivity, e.g. compared to automatic welding even five times, not to mention manual welding. Robot welding provides uniform and good quality quickly and cost-effectively. Especially for thicker materials, productivity. Submerged arc welding also has a significant safety and environmental aspect, as it does not emit heat, light or welding fumes.

Benefits of submerged arc welding:
• Speed and cost-effectiveness
• Suitable for large material thicknesses
• Suitable for handling large pieces
• Ensures consistent and good quality
• Best welding process for the working environment
• Relieves the employee from manual, physical welding

LEKO Group participates in PulPaper2022, Helsinki 7.-9.6.2022. In particular, the theme at the trade fair is our own product manufacturing, i.e. Siirtoruuvi Oy’s conveyors and LEKO Fans Oy’s industrial fans. At the department, you also have the opportunity to discuss the needs of the heavy and medium heavy metal industry with Lehtosen Konepaja and TK-Vilmet experts.

Siirtoruuvi products include conveyor process solutions, standard and customized screw conveyors,
complete conveyor screw pumps, conveyor screws, vertical screws, dilution screws, coils, screw bases and tearing screws.

LEKO Fans is an expert in industrial fan services that manufactures centrifugal fans for various industrial sectors. Our experts help customers ensure that their processes work by also providing fan condition monitoring and maintenance.

The companies of the manufacturing metal industry of the LEKO Group are TK-Vilmet and Lehtosen Konepaja.
TK-Vilmet is a subcontracting machine shop that manufactures machine and equipment structures and components according to customer needs as ready-to-install products or assemblies.
Lehtosen Konepaja is a system supplier, producing the customer’s individual products as ready-to-use product and machine.
The areas of production include system deliveries, manufacture of machine bodies and demanding machinable parts.

» Pulpaper 2022 homepage

The name of the company founded on 1 January 2021 is LEKO Fans Oy and it is a wholly owned subsidiary of Lehtosen Konepaja. In the future, the LEKO Group will consist of four companies: Lehtosen Konepaja Oy, LEKO Fans Oy, TK-Vilmet Oy and Siirtoruuvi Oy. The Group’s strength is to provide customers with total solutions, expert service in specialized areas and competitive machine shop technology.

Industrial fan services expert LEKO Fans Oy

LEKO Fans Oy offers expertise and fan solutions for industrial applications in various industries, such as the energy, steel, pulp and paper industries, the chemical industry, the mining industry and the food industry. The personnel have very long experience in the design, manufacture, maintenance and customer delivery of industrial fans and fan compressors to final destinations, as well as an understanding of the mechanical and aerodynamic performance requirements of radial fan compressors. The choice of product materials ranges from traditional steels to challenging environments that require superduplex steels as the material. “Special is our Standard” describes LEKO Fans sales arguments well.

LEKO Fans Oy product lines

Our operations can be divided into five different product lines, the first of which is projects. In projects, the fan delivery package typically includes drives connected to the fan (motor and frequency converter) as well as auxiliary equipment and possibly spare parts.

The second is renewals, i.e. fan delivery, which replaces the customer’s old complete fan with a new one. The delivery may include drives to be connected to the fan (motor and frequency converter) as well as auxiliary equipment and possibly spare parts.

Modernization means that the customer’s old fan rotor is equipped with a new LEKO Fans rotor package (impeller + bearing housing), which typically achieves better performance values without replacing the entire fan. Modernization typically includes drives to be connected to the fan (motor and frequency converter) as well as auxiliary equipment and possibly spare parts.

Expert aftermarket services provide important added value for our customer. In addition to LEKO Fans Oy’s fans, the spare parts service and spare parts deliveries cover all brands. Maintenance / technical services include e.g. fan maintenance / repair work, equipment and condition evaluations, performance measurements and problem solutions for all brands.

Professional Fans team at your service

With the help of our efficient international cooperation network, our products are delivered to all continents from America to China. According to our product line, our services include design and manufacture, new and modernized fans, assembly, maintenance and service plans, inspections and a comprehensive spare parts service.

Sales:
Peter Lönnqvist, tel. +358 40 168 4824
Jimmy Suominen, tel. +358 40 484 1106

The email addresses of our sales team are in the format firstname.lastname@lekogroup.fi

» LEKO Fans – Industrial fan solutions for demanding needs

”We manufacture heavy workpieces, the handling and welding of which takes a significant number of hours. We invest in welding automation so that we could further develop the quality and efficiency of our production process,” says Erkki Lehtonen, CEO of Lehtosen Konepaja. “By developing our operations and utilizing the latest technology to improve our readiness, we as a modern metal industry factory are responding to the challenges of the future.”

The latest LEKO Group investments are a heavy-weight PEMA APS 35000 handling table with 35 000 kg support capacity and a PEMA HD 7×5 welding tower for welding heavy and thick materials, to be delivered to Lehtosen Konepaja at Kokemäki. The size of the manufactured units and machine bodies is constantly increasing, and by investing in welding automation LEKO Group can answer the clients’ demands of high welding quality and production reliability.

The PEMA APS Skymaster APS handling table is an excellent solution for lifting, turning and tilting heavy and complicated workpieces. The height, angle and rotation speed of the workpiece are fully adjustable, which should be taken into account with respect to work ergonomy. This latest purchase, in addition to the two previous modern PEMA robot welding stations among others, complements LEKO Group’s capacity as a contract manufacturer of heavy and medium machine construction.

LEKO Fans will supply the world’s largest black liquor evaporator in South Africa with two dual turbo blower sets, two lines in parallel, with a combined engine power of 16 MW and an evaporation capacity of 400 tonnes per hour. In addition to spare parts, this very extensive project also includes commissioning services and warranty testing.

LEKO Fans Quality Control Process Starts at the Drawing Board

Starting from the definition of customer needs, quality control includes all planned and systematic measures to ensure the product meets all its quality requirements. As the manufacturer is responsible for the conformity of the product with the EU Pressure Equipment Directive, as well as legislation and regulations, the inspections and the final evaluation shall be carried out by a knowledgeable third party to maximize reliability. DEKRA Industrial Oy is an inspectorate accredited by the Finnish Accreditation Service FINAS and acts as an inspection body approved by the Finnish Safety and Chemicals Agency Tukes as an inspector of pressure equipment under national law. The Ministry of Economic Affairs and Employment of Finland has certified with the European Parliament and the Council (EU) that DEKRA is a Notified Body 0875 in accordance with the Pressure Equipment Directive PED 2014/68/EU. In accordance with the necessary assessment procedure, DEKRA will carry out a conformity assessment for the product by approving the plan, verifying the quality material required for the preparation of the product and reviewing the product at a pressure test.

In accordance with the high requirement level of the application, the blower material is made of extremely corrosion-resistant and acid-proof duplex steel. Duplex stainless steels are suitable for many corrosive environments. Lehtosen Konepaja uses high-quality materials, and their partner in procurement is Outokumpu, which specializes in steel production.

Water Pressure Test Ensures Compliance with Design and Manufacturing Values

For each turbo blower unit, DEKRA monitors a water pressure test to verify that the manufacturing process has been carried out according to the plan. The pressure test reveals, among other things, any possible leak points. During the pressure test, the product must prove to be durable and shape-preserving. The manufacturer is also required to carry out welding quality monitoring in the manufacture of pressure equipment. In order to meet the requirements, the manufacturer must perform coordinated welding and use only certified welders. In the manufacture of the product, weldability in particular must be taken into account already at the time of designing the product and selecting the materials.

LEKO Fans turbo blowers are an exceptional target for pressure testing. Testing was carried out in accordance with PED regulations to meet the requirements of the customer and the product’s final destination. The audit was focused on the visual quality of the product and the quality of welding. The performance of the pressure test was documented in the test protocol and the certification body’s Certificate of Conformity allows the manufacturer to CE mark the product.

Lehtosen Konepaja Quality Assurance Also with PMI Measurement

The quality assurance of Lehtosen Konepaja covers the entire manufacturing process from the material selection to the welding quality requirements and assembly. Systematic quality control is essential for all metalworking, especially for checking safety-critical positive materials. The PMI measurement distinguishes pure metals from alloys quickly and accurately. All parts and materials associated with the same process must be tested to ensure the best possible quality for the customer and to prevent problematic situations caused by the wrong metal alloy.

The PMI measurement was carried out by Kiwa Inspecta, which operates as a control body under several EU directives and national legislation. The supplied PMI measurement confirmed that the turbo blower materials were duplex steel, and the measurement technology also allowed the checking of a small/narrow point, e.g. the weld seam. Inspecta also examines the technical documentation submitted by the customer. In module G, the Pressure Equipment Directive does not directly require a separate certificate of the examination of the plan, but in accordance with the generally accepted practices in the field, Inspecta provides an opinion on the acceptability of the design data and other technical documentation.

Lehtosen Konepaja is strongly involved in promoting energy efficiency and implementing a national energy and climate strategy. Finland aims to be a carbon neutral country by 2035. CEO Erkki Lehtonen is driving the Lehtosen Konepaja and the entire LEKO Group toward this goal, and he believes that this can be achieved. “New habits, artificial intelligence and energy-saving devices can have a significant impact on the energy consumption of both industry and households. Investment such as utilizing waste heat and developing new energy forms will save a vast amount of electricity in the future”, Erkki Lehtonen assures. One example of the company’s involvement in the joint effort to fight climate change is that the welding in the workshop is largely done by solar power and district heating.

Energy efficiency – a strong competitive edge

At Lehtosen Konepaja cleanliness and organization is important. Recycling is part of every day business and new staff is guided through the waste sorting routines already in the job orientation phase. Organization extends to the use and storage of individual tools and equipment. “At the workshop, we have measured our own performance and systematically sought to address deficiencies. Energy saving and the circular economy are an integral part of the company’s environmental strategy. By working more efficiently, improving our working conditions and investing in logistics and public order, we work in an economically advantageous way”, Erkki Lehtonen says. A huge amount of electricity and heat has been saved through investments and modern technology. Energy savings have also resulted in economic savings, which is a competitive advantage in the technology industry.

Welding produces a large quantity of impurities into the air, and therefore the ventilation in welding shops is demanding for the well-being of both the employees and the environment. In an hour, 2,5-3,5 times the room volume of air has to be circulated. When mechanical ventilation is used at the workplace, it has to be kept operational and cleaned sufficiently frequently, since the health of the employees must not be endangered due to, for instance, ventilation machinery malfunctions.

At Lehtosen Konepaja, cleaning the air of the welding shop is taken care of with automatised Mastervent Ltd KRS-THR ventilation machines which were deployed in the early fall. In staff interviews, the feedback has been positive; the effect of clean air in the working spaces has been immediately noticeable. The air temperature, moisture, and movement are also controlled through the ventilation. This happens by processing the intake and exhaust air. The premise is a displacing air distribution, where the exhaust with its impurities are sucked out from above the welding area and fresh air is brought in. The ventilation machinery, equipped with exhaust heat capturing and an automatic cleaning system, is also an environment-friendly solution that brings the company significant savings while ensuring the cleanest air in Finland at the welding shop.

The KRS-THR has been designed especially for welding and paint shop needs, and use experiences going back for years are very successful. The ventilation machines have no filters at all to change and clean periodically. The ventilation solution used at Lehtosen Konepaja has an efficient special rotor, which is kept clean using an automatic high pressure washing system. The exhaust is not filtered, but the impurities in the air get caught in the rotor’s disc, from which they are cleaned automatically. The washing water is conducted via special pools into the sewer. The revolving disc transfers the thermal energy in the exhaust directly into the intake air at up to 85% efficiency.

Lehtosen Konepaja’s welding and machining operations are backed by the workshop’s lineup of preheating furnaces, the newest of which is a gas-operated bell furnace by HeatMasters, designed for handling large pieces. The large furnace operates on gas, which is an economical and energy-efficient solution. Collecting waste heat also affects the workshop’s energy consumption and heating.

The location near the workshop’s new extension hall, environmental conditions and the size of the heated pieces were taken into consideration when choosing the furnace. The preheating furnace is located outside, saving space inside the hall while being logistically close by. This new acquisition complements the resources of other HeatMasters electric furnaces. It was tailor-made to fit Lehtosen Konepaja’s and the entire LEKO Group’s needs. Measuring 8x8x4 meters, the furnace can heat-treat large welded objects. The preheating furnace contributes to ensuring that work and production progress smoothly.

Heat treatment of metal refers to a process in which a metal object’s temperature is increased to achieve desired properties. Metal does not melt during heat treatment, but it has an effect on an object’s hardness, durability, viscosity and wear resistance. The effects of heat treatment can be applied to an entire object, or only its surface or a specific part. Metal structures can have harmful tensions, for example as a result of welding. Stress relieving is performed at a temperature that is lower than the metal’s annealing temperature. The procedure relieves tension from the metal before it is worked on.

Welcome to explore LEKO Group service offering and opportunities at the Subcontracting Fair in Tampere, 24-26 September 2019. The fair is an opportunity to forge new partnerships and strengthen existing customer relationships. You can find us at A 1002, where we represent a comprehensive engineering concept for the engineering and metal industry throughout the internationally expanding group. 

TK-Vilmet, a member of the LEKO Group, will appoint a new CEO when Lasse Tyynysniemi retires. However, Lasse will continue his employment at TK-Vilmet as a special assistant to the new CEO, and provide background support during the transition period.

-Together with Juha Mäkelä we intend visit to our customers, so that the new CEO can begin his work in the most controlled way as customer relationships become stronger, says Lasse. He also assures that he will be at the customers and stakeholders disposal, even if the main responsibilities are transferred to Juha.

Lasse Tyynysniemi (left.) and Juha Mäkelä

TK-Vilmet, a medium-heavy mechanical engineering company based in Mänttä-Vilppula, is part of a larger group offering customized products to their clients.These include manufacturing of various components and steel structures for the technology industry. The company will furthermore strengthen its operations with additional production staff. Future plans also include investing in a new assembly hall.