Standards for the differences in casting production processes between high-quality and low-quality domestic valves

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A complete fluid control system requires a complete set of valves for control; so, what is the manufacturing process for these valves? What are the differences in the production and processing techniques for valves? What are the differences in casting? Distinguishing between high-quality and low-quality? Different machines? Core interior? Sales volume of the product? First, let’s understand the production process of valves. Valves are made by melting steel and then casting it (note: sand casting is used for low-pressure valves, while forging is used for high-pressure valves). After casting, the parts are cleaned, inspected, machine-machined, checked for tolerances, ground on the surface, inspected again, plated, and the plating is tested. The various valve components are then assembled, the valve is subjected to pressure tests, temperature tests, and material tests. Finally, the finished product is inspected, packaged in wooden boxes, and only after going through all these complex procedures is it approved for release. 　　 Casting involves pouring molten metal into a casting cavity shaped to match the desired form, and after it cools and solidifies, the desired shape or prototype is obtained. Quality control: During the production process, all unfinished products are monitored by the quality control department; later on, the quality assurance team conducts random inspections of the entire batch, focusing mainly on the packaging and storage of the finished products. At the same time, the requirements of the international market for domestic valve products will also evolve over time; there will be higher demands regarding the quality, packaging, and delivery timelines of Chinese-made products. These requirements will even extend to the production process and product development, with an emphasis on integrating the products with environmental protection, energy resources, and the cultural environment. The huge market and its central strategic position will further attract the manufacturing centers of valve multinational companies to relocate to China. Integration with foreign companies will continuously improve the quality of Chinese valve products as well as the competitiveness of these enterprises. While continuing to expand in traditional markets such as the United States and Japan, it will also see widespread growth in Southeast Asia, the Middle East, Russia, Europe, Africa, and other regions. 　　 Differences in casting processes between high-quality and low-quality valves 　　 1. Differences in casting processes 　　 The casting process used for most products of lower quality, as well as some mid-range products, is sand casting. That is what people usually call (sand casting). Products manufactured using this process have a loose internal structural texture in the valve body metal, are prone to rusting and perforation, and are easily subject to internal defects such as (sand holes) and (perforations). It might not be visible from the outside. However, after being used for a period of time, internal leakage, poor sealing, and even more serious defects may occur. This results in a short product lifespan. It is understood that low-end valves have a service life of only 1–3 years; even those with a longer lifespan start to develop problems after about 5 years. High-end products and mid-range products manufactured by powerful companies are produced using precision casting. It involves using precision casting equipment to cast with steel molds. Such process conditions are already quite common abroad. The products manufactured using this process have a dense internal microstructure of the valve body metal. It meets quality standards, is wear-resistant, and has a long lifespan. For the same valve body, the products produced using the two different manufacturing processes have different weights, as well as different material consumption. The weight of valve bodies manufactured by precision casting generally differs from that of those made by sand casting by about 1/3. Thus, for the same product with the same functions, the price can be completely different. 　　 2. Different machine processing techniques: For products at the lower end of the market or certain mid-range products, in order to reduce costs, simple processing machinery is used, along with straightforward techniques; as a result, the precision of machine processing is low, which undermines the quality of these products. Powerful companies all use specialized equipment or imported specialized equipment for processing. Processing standards ensure high precision. The assembled product components have good compatibility with each other, making it less likely for quality issues to arise, allowing users to use them with confidence. 　　 3. The manufacturing processes of the valve cores used vary. The valve core is the core component of a valve; although most products available on the market use high-quality valve cores, there is a significant variation in the quality of these high-end valve cores. The key aspect of a high-end spool lies in its degree of sophistication. For many domestic valves, the valve bodies are manufactured using domestic casting methods, while core components such as the valve cores are imported. The difference in quality between imported and domestic products directly affects the service life of the valve cores, and this is one of the main factors that influence the overall service life of the valves. Starting from the application scenarios of the product, user needs, and consumers’ usage habits, developers conducted thorough research on existing indoor locks available on the market. By taking into account the feedback from experienced industrial clients such as door manufacturers, they designed new lock functions to meet these requirements; casting companies pay even more attention to the user experience. 　　 Currently, the market offers domestic valve cores, imported valve cores, as well as those manufactured domestically from high-end imported brands. Due to differences in quality, their prices range from several dozen yuan to over a hundred yuan or even several thousand yuan. For low-end products, in order to save costs, the quality of the valve core is relatively poor. Short service life. A good valve core features a soft feel and flexibility, with no gaps or looseness; its service life can generally be guaranteed for 5-10 years. Valve cores of poor quality feel rough to the touch, lack a smooth feel, rotate stiffly, and make the operation awkward. In terms of competitive behavior, there is an increase in cooperation among companies regarding resource sharing. On the one hand, manufacturers are strengthening their control over retail outlets, striving to reduce the number of sales stages and cut down on sales costs, thereby developing more specialized sales channels; meanwhile, companies’ sales models are evolving to be capable of adapting to diverse markets. On the other hand, trends in the sales industry have led to an increasing prominence of large home appliance chains, which have gained greater control over the industry and have joined in price competition that was previously dominated by manufacturers. Large retailers, thanks to their wide market coverage, large-scale purchasing power, and cost advantages, will increasingly gain control over manufacturing companies in areas such as product pricing and payment terms. As a result, small and medium-sized enterprises at the lower end will be at a disadvantage in competition under this trend. 　　 4. Different plating processes: Lower-end chromium-plated valves typically have a nickel coating of about 5 microns, with a chromium coating of around 0.1 microns. High-end valves generally have a nickel plating layer of around 15 microns, and a chromium plating layer of around 0.3 microns. The plating layer is thin, giving it only a (shiny) appearance. With a thick plating layer, it feels as though the product’s brightness comes from within, giving it a (cyan) tone. There is also an epoxy coating; gate valves, ball valves, butterfly valves, filters, and other components used in urban pipelines typically have their surfaces coated with epoxy, which prevents the valve bodies from being damaged due to environmental corrosion. There are two simple criteria to determine the quality of electroplating. One is (photo). It involves looking at the product to determine whether the shadow appears dark or light. If it appears dark, it indicates that the plating quality is good; if it appears very light, then the quality of the plating is low. The second is (India). Regarding the product, when a fingerprint is pressed on it, if the fingerprint gradually fades away after some time, it indicates that the quality of the electroplating is good; if the fingerprint does not fade, it means that the quality of the electroplating is poor. 　　 5. Increasing demands in valve technology 　　 As China’s global standing continues to rise, more and more ** around the world are starting to use Chinese valve products. Our products are sold throughout the world, which has, to some extent, promoted the development of domestic valve manufacturing. In recent years, as global economic integration has accelerated, China’s valve manufacturing techniques have gradually become a key force in the world’s valve industry. In some developed countries – particularly the United States, Germany, the United Kingdom, and other such nations – the demand for valve casting is increasing at a rate of over 10 percent per year. Sales have reached unprecedented levels. Valve manufacturing is a labor-intensive industry, and Yongjia, known as the hometown of valves, has taken advantage of its traditional cost advantages to become a hub for valve manufacturing. 　　 Taking all these factors into account, in terms of cost-performance, consumers should focus on choosing mid-to-high-end products; among similar products, those made through precision casting should be preferred. Although such products may be more expensive than low-end ones, their quality is guaranteed, making them a much better choice in the long run. As one of the major valve-producing countries in the world, and gradually becoming a major player in valve processing and export, the country has a vast market and high demand for such products. With the development of the social economy, the valve industry will also exhibit new trends under the new circumstances. As the saying goes: Buy expensive items for hassle-free use; buy cheap ones and you’ll have to deal with plenty of troubles.