Risk of valve quality control brought by admittance system of casting industry

In recent years, the voice of environmental protection has been growing, and the government’s requirements for pollution rectification in the foundry industry have never stopped. As an industry with high energy consumption and high pollution (mainly dust pollution and noise pollution), the Ministry of industry and information technology of the people’s Republic of China issued the entry conditions for China’s foundry industry in the past few years, aiming to guide the healthy, orderly and sustainable development of the foundry industry, and accelerate the elimination of foundry enterprises with backward technology, high energy consumption, serious pollution and poor working conditions.

The result of the implementation of these access rules seems to be to shut down small foundry enterprises, to centrally plan and renovate foundry enterprises to designated industrial areas, and to require centralized matching of relevant technical testing equipment and pollution treatment. For the foundry enterprises, the admittance rules require the foundry enterprises to carry out technological innovation and adopt low energy consumption, low pollution, low emission and cost-effective foundry technology. At the same time, the admission rules require foundry enterprises to carry out enterprise quality management, such as obtaining ISO9001 certification or TS16949 certification, so as to improve the foundry production level.

The admittance system sets the threshold for the foundry enterprises and sets a certain barrier for the valve manufacturers to enter the foundry industry. Therefore, many valve manufacturers begin to look for the foundry enterprises with certain technical strength and certain cost advantage as their own suppliers, and carry out valve project development with their advantages or the cooperation of both parties.

The valve manufacturer can not directly participate in the production and quality management of the casting enterprise in the valve casting, so the valve manufacturer must consider the quality problems that the casting defects may bring to the valve, for example, the pressure test requirements of the valve shell caused by the casting small pores are not up to standard. In addition, the risk of valve casting supplier quality also includes the following aspects:

(1) The quality risk of the casting supplier may sometimes be sluggish. Casting quality defects can not be found directly after the completion of the casting process. The airtightness of valve castings, unlike other defects, can not be easily identified, but can only be detected after the machining is completed. When it is found, it has been reflected in batches. This kind of time delay will lead to batch product quality accidents.

(2) The quality risk of the casting supplier may be converted into the risk of rising cost of valve casting and the risk of rising price of valve. When the quality qualification rate of the casting enterprise can not reach the expected casting qualification rate, the casting enterprise will raise the price or refuse to accept the order, and the valve manufacturing enterprise will either accept the rising cost or redevelop the casting supplier. Once the price of valve products rises, it may cause unsalable valve products.

Starting from the phenomenon that the qualified rate of spot check quality in the valve market is less than 80%, this paper analyzes the quality requirements of valve products, points out the possible quality problems in the valve manufacturing process, and analyzes the possible quality defects in the casting process and their impact on the valve quality. At the same time, it points out that the admission system of foundry industry may cause supplier quality risk to valve enterprises, including product quality risk, valve cost risk and price risk.