Domestic pressure control valves have made significant progress in both conventional and cryogenic applications

the short lifespan of the valve cores in domestic control valves. While this is certainly related to process operating conditions, it should also be linked to the manufacturing of control valves. We strive to select valve cores with appropriate structures, and we hope that domestic control valve manufacturers can enhance the stability of their manufacturing processes. This involves a systematic engineering approach encompassing materials, processing, assembly, and inspection.

Secondly, we should focus on the soft-seal valve seat. The soft seal of domestic control valves has a short lifespan, leading users to prefer metal-seal regulating valves. In fact, in Europe, a certain proportion of regulating valves use soft-seal valve seats. When suitable for the process, soft-seal valve seat regulating valves can reduce most of the investment and also have a guaranteed lifespan. In terms of non-metallic materials, there is a significant gap between domestic products and foreign ones. Take the faucet in our daily life as an example, which is a simple valve. The sealing disc is usually made of rubber and has a short lifespan. This mindset also affects valves in the industrial field.

In the petrochemical industry, it is sufficient to select control valves appropriately. Generally speaking, there is no need to design regulating valves for ordinary operating conditions beyond the standard. If the operating conditions are harsh and imported regulating valves are used, it is recommended to increase inspection steps and testing reports.

The so-called requirements for safety, operability, and other aspects are all based on proper selection and use. For different working conditions, analysis should be conducted from the perspectives of valve structure, material, type, and limiting conditions. Of course, correct operation and proper maintenance are also important factors.

Domestic control valves have made significant progress in both conventional and cryogenic applications, performing well. However, strictly speaking, there is still one product in the domestic control valve sector that needs improvement: the positioner. Currently, all well-known positioners are foreign brands. The stability and repeatability of domestic positioners lag behind those of foreign ones, and in practical use, imported positioners are generally preferred.

Secondly, there is a gap between domestic precision machining and assembly technology and that of foreign countries. When the same components are processed and assembled domestically, the quality is always compromised. Even some imported big brands have repeatedly experienced such incidents. The root cause lies in the inability to maintain long-term stability in the quality system.

We should strive to surpass foreign products and intensify our research and development efforts.

It should be said that the quality of imported brand control valves is generally excellent. Of course, they are expensive and have a longer delivery time. Due to geographical constraints and certain weaknesses of multinational enterprises, imported brand control valves generally do not perform well in after-sales service; in the impression of many users, products from big brands are always slow in after-sales service, or they cannot receive good after-sales service,

On the contrary, domestically produced control valve products generally perform well in terms of service. Whether it's the follow-up of after-sales service, timely replacement of spare parts, on-site adjustments and improvements, etc., domestic control valve manufacturers have considered these aspects very comprehensively and are very considerate to users.

We believe that, except for the introduction of foreign control valves in particularly critical operating conditions, domestically produced or joint venture control valves should be the preferred choice for most other situations. This approach reduces procurement costs, ensures timely delivery, and guarantees on-site service.

Regarding the development trend, there are two points:

Firstly, in the current international pressure control valve market, the products occupying a dominant position are spherical single-seat valves, sleeve valves, regulating butterfly valves, and cam flex valves. In our domestic market, the first three types have already occupied half of the control valve market, but cam flex valves have not been widely used. Why haven't good things been widely promoted?

In fact, the cam flex valve structure boasts good control performance and relatively high flow capacity. It offers price advantages for diameters above 4 inches. Brands like MASONEILAN, FISHER, and FLOWSERVE all produce cam flex valves, which are widely used abroad. However, it is a pity that they have not been widely promoted domestically. Ten years ago, we discussed the prospects of cam flex valves. From a theoretical perspective, their valve cores are relatively thick and thus wear-resistant, which may be a trend for future development. However, they have not been widely adopted in practical applications. Users are not receptive to them, and there are not many manufacturers producing them. The reason lies in the insufficient understanding of rotary valves in China at that time. No one was willing to invest time in research and development, and there were too few manufacturers producing rotary valves, naturally leading to a low market share. Nowadays, domestic butterfly valve products have made rapid progress, and it should be said that cam flex valves still have a promising future.

Secondly, there's the slide valve, which boasts a straightforward structure. Inside the valve body, there are two slide plates perpendicular to the flow direction of the medium. One slide plate is fixed inside the valve body and features throttle slots of varying lengths but the same width. The other, a movable slide plate connected to the valve stem, closely adheres to the fixed slide plate and also features throttle slots. By moving the slide plate, the size of the medium's flow area can be altered, thereby controlling the flow rate of the medium. This valve structure is highly suitable for clean gas conditions, requires minimal maintenance, and is worthy of widespread application.