Quality through decades of experience, materials engineering and comprehensive testing
We meet the highest demands and quality standards of our renowned European customers.
At BENDS and WELDS, quality does not begin with final inspection. It is an integral part of the entire manufacturing process – from the selection of raw materials through production and testing to documentation and delivery.
Clear processes, qualified staff, modern testing technology and full traceability form the basis for compliance with demanding project and customer specifications.
Quality management and certifications
Certified Processes and Standards
BENDS and WELDS operates on the basis of established management and quality systems. Regular internal and external audits ensure that processes are continuously monitored and further developed.
Our certifications and approvals include, amongst others:
- DIN EN ISO 9001
- DIN ISO 45001
- DIN EN 1090-1 & -2 EXC4
- Pressure Equipment Directive 2014/68/EU (PED)
- AD 2000 regulations
Accredited testing laboratory
Non-destructive and destructive testing in-house
To ensure the quality of our products, non-destructive and destructive tests are carried out in accordance with national and international standards. The type and scope of the tests depend on the specific project requirements and areas of application.
At BENDS and WELDS, destructive tests are carried out in our own independent testing laboratory, located directly at the production site. The testing laboratory operates to the highest quality standards and is accredited to EN ISO/IEC 17025. Accreditation and supervision are carried out by the Czech Accreditation Body.
The major advantage of having our own independent testing laboratory lies in the flexible and fast performance of tests, as well as the efficient handling of third-party inspections directly on site.
Typical destructive tests include, amongst others, tensile tests, Charpy V-notch impact tests and bending tests. In addition, we carry out various non-destructive tests such as ultrasonic testing, magnetic particle testing, dye penetrant testing, radiographic testing and hardness testing.
Traceability and documentation
Full traceability
Throughout the entire manufacturing process, all relevant material, production and test data are systematically recorded and documented.
This enables every single pipe bend to be fully traced from the raw material right through to the finished product. The documentation is prepared in accordance with the respective project requirements and accompanies the delivery to the customer.
Depending on the specification, the documentation includes:
- Delivery documentation
- Raw material certificates
- 3.1 or 3.2 certificates in accordance with DIN EN 10204
- Heat treatment diagrams
- Test reports
- Dimensional reports
- Coating certificates
International third-party approvals
Quality under independent supervision
Third-party inspections carried out by internationally recognised testing and certification bodies are an integral part of many projects.
Our products and manufacturing processes are regularly monitored and tested by independent organisations. These include, amongst others:
- Vinçotte
- Bureau Veritas
- TÜV
- Lloyd’s Register
- UDT
- Apragaz
- DNV
- Other organisations commissioned on a project-by-project basis
Our long-standing collaboration with these institutions confirms the quality of our products and the reliability of our manufacturing and testing processes.
Test procedures
Comprehensive testing in accordance with project requirements
Depending on the material, application, and customer specification, we perform both non-destructive and mechanical testing. The scope and performance of the tests are carried out in accordance with the respective project requirements, applicable standards, and customer specifications.
Destructive testing
The tensile test is a standardized material testing method used to determine the mechanical properties that characterize the strength and deformation behaviour of a material. Tensile testing can be performed at both room temperature and elevated temperatures.
In a tensile test, a standardized specimen with a defined cross-sectional area is subjected to uniaxial tensile loading until fracture. The tensile load is applied continuously, without impact, and at a defined test speed. During the test, both the applied force F and the elongation ΔL within the gauge length are continuously recorded. The engineering (nominal) stress is calculated from the measured force and the original cross-sectional area S0 according to σn = F/S0. The engineering strain is determined from the elongation ΔL relative to the original gauge length L0 according to ε = ΔL/L0.
The result of the tensile test is the stress–strain curve, from which the relevant mechanical material properties, such as the yield strength, ultimate tensile strength, and elongation at fracture, can be determined.
The Charpy impact test is a standardized material testing method used to determine the toughness of a material under impact loading. A standardized specimen with a defined V- or U-notch is tested at room temperature or at lower temperatures.
During the test, a pendulum hammer with a defined kinetic energy strikes the side of the specimen opposite the notch. The impact causes the specimen to deform plastically and eventually fracture, either partially or completely. The energy required for deformation and fracture is absorbed from the kinetic energy of the pendulum and depends on both the material and the test temperature. Depending on the applicable testing standard, the pendulum hammer is equipped with a striker having either a 2 mm or an 8 mm radius. If the material thickness does not allow the preparation of standard-sized specimens, sub-size specimens may also be used in accordance with the requirements of the applicable testing standard.
The greater the energy absorbed by the specimen during fracture, the lower the height reached by the pendulum after passing through the specimen. The absorbed impact energy is determined from the difference between the initial and the remaining potential energy of the pendulum. If no energy were absorbed, the pendulum would swing back to approximately its initial height.
The result of the Charpy impact test is the Notch Impact Energy, expressed in joules (J). It provides a measure of the material’s toughness at the specified test temperature.
The bend test of welded joints is a standardized testing method used to assess the quality of a weld. A test specimen extracted from the welded joint is plastically deformed without reversing the bending direction so that, depending on the test configuration, either the weld face or the weld root is subjected to tensile loading.
The specimen is supported on two parallel rollers and bent at the midpoint between the supports by means of a bending mandrel under a continuously increasing load. The load is applied perpendicular to the specimen surface until the specified bend angle, typically 180°, is reached. After completion of the test, the outer surfaces of the bent specimen are visually inspected for cracks or other surface imperfections.
Non-destructive testing
Ultrasonic testing is a non-destructive testing method used to detect material imperfections by means of high-frequency sound waves. A couplant is applied to the surface of the test specimen to ensure optimal transmission of the ultrasonic waves between the probe and the component.
Using a probe that transmits and receives ultrasonic waves, the surface to be inspected is systematically scanned. When the sound waves encounter interfaces within the material, such as voids, inclusions, cracks, or other discontinuities in the microstructure, they are reflected back to the probe. The position of the reflectors within the component is calculated from the difference in transit time between the transmitted and received signals. The signals detected are displayed as an inspection image, which can be used to assess the location and size of any defects.
Magnetic particle testing is a non-destructive testing method used to detect cracks and near-surface imperfections in ferromagnetic materials. The test area of the component is first magnetized, causing magnetic flux lines to flow through the material. Discontinuities such as cracks or voids disturb the magnetic field because they cannot conduct the magnetic flux to the same extent as the surrounding material.
When the magnetic flux encounters such imperfections, part of the flux is forced to leave the surface, creating magnetic leakage fields. These leakage fields are used to detect defects. Magnetization can be achieved, for example, by current flow, a magnetic yoke, or handheld magnets. The inspection area is then treated with either fluorescent magnetic particles or black magnetic particles applied to a white contrast background (black-and-white method). The magnetic particles accumulate at areas with leakage fields, making cracks and other surface imperfections visible.
Dye penetrant testing is a non-destructive testing method used to detect open surface imperfections such as cracks or pores. It utilizes the capillary action of fine surface discontinuities to allow the penetrant to enter the openings and make them visible. The complete penetrant testing system consists of a penetrant, an intermediate cleaner, and a developer.
After the penetrant has been applied and the excess penetrant has been removed, the residues remaining within the imperfections are drawn out by the developer and made visible. A major advantage of dye penetrant testing compared with magnetic particle testing is that it can be applied independently of the material’s magnetic properties. Therefore, surface imperfections can also be detected in non-ferromagnetic materials.
Radiographic testing is an imaging technique used in materials testing to visualize material defects. Using a suitable radiation source (e.g. an X-ray tube), the density variations of the workpiece are recorded on an X-ray film.
A projection image of the component is generated on the X-ray film.
Variations in material thickness or density can be identified by differences in the image density. The thicker or denser a component is, the less radiation can pass through it, resulting in a lighter appearance on the X-ray film.
Radiographic testing is, in particular, a standard method for inspecting safety-critical welds, e.g. in power plants.
Hardness testing is a mechanical testing method used to determine the resistance of a material to indentation. Standardized test methods are applied to evaluate the hardness of a material through defined comparative measurements. The Vickers, Brinell, and Rockwell hardness testing methods are among the most widely used and recognized procedures.
A hardness tester generally consists of a defined indenter, which is pressed into the surface of the specimen with a specified test force for a defined dwell time. The resulting indentation is then measured, and the hardness value of the material is determined based on the measured parameters.