China wang wang wang Company News

1、 Differences in the production process After rolling steel plates or strips, stainless steel welded pipes are welded together to form equipment and molds. The inner wall of the pipe usually has welds, and seamless pipes are made from round pipe blanks and drilled, cold rolled, and drawn through hot extrusion production processes. There are no welding points inside the pipe. 2、 Appearance differences of steel pipes For stainless steel welded pipes, the tolerance for wall thickness is very small, and the thickness of the entire circumference is very uniform. The steel pipe has high precision, high brightness on the inner and outer surfaces, and the length can be set arbitrarily. The precision of seamless steel pipes is low, the wall thickness is uneven, the brightness of the inner and outer surfaces of the pipes is low, the cost of fixing dimensions is high, and the installation and black spots inside and outside are also included. Therefore, usually produced seamless pipes have thicker walls. 3、 The difference between performance and price Seamless pipes have higher corrosion resistance, pressure resistance, and high temperature resistance than welded pipes. With the improvement of the manufacturing process of welded pipes, the mechanical properties and mechanical properties are gradually approaching those of seamless pipes. Seamless pipes are more complex in the manufacturing process and more expensive than welded pipes. According to the characteristics and differences between stainless steel seamless pipes and welded pipes, in order to achieve economic, aesthetic, and reliable results, it is necessary to choose reasonable applications. When used as decorative pipes, product pipes, and support pipes, the surface effect is generally good, and stainless steel welded pipes are generally required; Usually, stainless steel welded pipes are used for low-pressure fluid transportation, such as water, oil, gas, air, hot water or steam, and other low-pressure systems. 3. Stainless steel seamless pipes should be used for power plants, nuclear power plant boilers, high-temperature, high-pressure, high-strength requirements, high-pressure, high-pressure infusion pipelines, industrial engineering, and large-scale equipment infusion pipelines. 4. Stainless steel welded pipes are usually used for liquid transportation below 0.8MPa, while seamless pipes can withstand liquid transportation above 0.8MPa. If the pressure requirement is not high, using welded pipes is more economical.

“We should keep in mind that high-performance seamless stainless steel needs a certain amount of costly alloying elements to form it into high-performance products. The Industry is calling for outstanding, flexible technology expertise, and from my perspective, a ‘good enough’ approach is, in many applications not purposeful. As a manufacturer, you can lay out your alloying approach in accordance with the minimum requirements defined by industry standards. Or, based on your strong industry knowledge, you can adapt realistic operation requirements to your product, which will then be overdesigned compared to the standards. However, the chemical processing industry (CPI) requires expertise to create an economical, reliable solution for an operating unit that has to stay flexible in the feed it processes.” A typical example is DMV 304L versus standard 304L (UNS S30403). Compared to the minimum standard requirements of ASTM, the alloying concept of DMV 304L typically presents 19% Cr and 11% Ni to comply with the realistic needs under operation.” “Highly aggressive environments in the CPI industry are screaming for consistent, corrosion- and temperature-resistant seamless stainless tubes, which should be “easy-to-weld”. The effort of mechanical cleaning operations, shutdowns and new integrity tests caused, e.g. by sensitisation and forming of secondary intermetallic phases in the microstructure of stainless tubes, need to be considered from the design stage.” High-alloyed duplex “High-alloyed duplex stainless tubes in DMV 29.7 support the main goals of the urea industry to operate in well-controlled maintenance periods and avoidance of unforeseen (major) shutdowns in different areas of operation units. Even in low oxygen environments, these duplex tubes present excellent resistance to several corrosion mechanisms, e.g. intergranular corrosion, pitting and crevice corrosion and stress corrosion cracking. Due to its highly sophisticated alloying concept and carefully-controlled heat treatment during tube production, all MST products show a well-balanced microstructure for the target application.”   Facing tough challenges “We provide a high-quality concept combining clever alloying concepts, well-controlled raw material supplies, stable hot-extrusion and cold-finishing processes realising very tight dimensional tolerances to comply with the highest testing requirements,”In different configurations, such as heat exchanger tubes, furnace tubes, piping or instrumentation tubes, MST products withstand extremely corrosive environments at high temperatures and pressures. DMV 200 pure nickel and DMV 400 nickel-copper alloy tubes are increasing reliability in desalination equipment, atmospheric rectification units and environments where units are exposed to alkali-chloride concentrations, vinyl chloride monomers and many others.” “Depending on the engineering design needed, we act to the guiding principle – where a customer identifies a challenge, we see an opportunity! Within our colourful bouquet of high-quality duplex, nickel, nickel-copper and austenitic seamless stainless tubes, we offer customised solutions for many different challenging industries.”   Low CO₂ footprint MST tubes have a very low CO₂ footprint due to a large amount of high-class quality scrap the company uses to produce its raw materials. Circularity is a central focus in all its efforts to reduce greenhouse gas emissions to an absolute minimum. “Our products generate added value in terms of life duration in highly corrosive stressful environments, offer optimised weldability and finally are beneficial for the customer’s total cost of ownership.”