What are the differences between domestic and imported control valves?

The materials, manufacturing processes, and assembly techniques for domestic valves are not up to standard! All these factors combined lead to a short lifespan and poor reliability; domestic control valves simply cannot be used in critical applications due to the high risks involved. That’s why imported valves are expensive.

Domestic valves are inferior mainly in terms of materials and manufacturing precision. But then again, in less demanding operating conditions, there’s no need to use such expensive imported valves; some owners simply can’t afford them. Domestic valves work just fine in such situations, so a valve that meets the requirements of the operating conditions is a good valve

Valve manufacturing has a long history abroad, where there is more experience, particularly in design and manufacturing, and the precision of processing is higher. Another reason for the higher prices is the high labor costs. China’s valve manufacturing capabilities have made significant progress; the products manufactured locally are very similar to those imported, so there is not much difference in performance. However, for critical components and interlock valves, it is still more reliable to use imported ones.

Materials, precision – high-quality imitations, but domestic production is constantly improving. Here, apart from the critical components, we are gradually replacing them with domestic alternatives.

1. In petrochemical refining units, the pressure in hydrogenation units is considered high. For the larger valves in early hydrocracking processes (such as those with a diameter of DN100 and above), it was emphasized that they had to be imported – why? I’m not confident using domestic products ； Materials are also one of the reasons for concern, but users feel more at ease when the valve bodies of imported valves are cast or produced in South Asia. 2. Many users are influenced by herd behavior and focus on performance; in particular, they have a strong sense of risk but rarely use quantitative data for objective evaluation. Only a few years later, when some users resorted to using domestic products out of necessity or by chance, did domestic valves begin to be used on a large scale. Of course, domestic valve manufacturers have also made significant progress in areas such as key sealing gaskets. 3. The same is true for control valves; in fact, there are domestic control valves that can meet the requirements. Moreover, with current international cooperation, foreign products are used for components such as positioners, which ensures that the control accuracy meets the required standards. 4. The difference between some domestic control valves and branded products lies not in aspects such as material processing, but in design. This design gap lies not in the adjustment performance, but rather in aspects such as cavitation prevention design, noise reduction design, and multi-stage pressure reduction design. Improper handling of these steps leads to valve stem vibration and fatigue fracture. 5. Another common problem with damaged control valves is that the actual operating conditions deviate from those intended, or the design of the controls takes excessive account of safety margins, resulting in deviations in the operating conditions during selection and use.

Take ball valves as an example: To compete on a low-cost basis, domestically produced ball valves use domestic gaskets, which results in a significantly shorter lifespan for these valves. Additionally, their manufacturing precision is not high. When assembling ball valves, it is necessary to tighten the connecting bolts in order to achieve sealing, and this increases friction between the ball core and the gaskets, leading to faster wear of the gaskets and thus a shorter lifespan. High-end valves, on the other hand, have high manufacturing precision, allowing them to achieve good sealing without the need for tight connections. This is also why many domestic valves require more torque to function properly compared to imported valves. There are also differences in casting techniques, and these can be noticed just by looking at the appearance of the valves. There are several reasons why imported valves are much more expensive: 1. Imported ball valves are inherently more expensive, and then there are additional costs such as tariffs, shipping fees, and domestic taxes; sometimes one-third of the price goes towards these expenses. 2. Imported products often come with various certifications and features, such as explosion-proof certification, fire-resistant certification, SIL certification, and anti-static functions. These are generally not required in domestic markets, but they are included in the price of the valve. 3. Labor costs abroad are higher (but this is not the main factor). 4. Many imported valve brands do not actually manufacture their own products; many foreign valves are sold under licensed brands, which naturally makes them more expensive. For example, the Taiwanese MARS brand of ball valves mentioned here is sold under licensed brands such as German Gemi, Finnish AVS Valves, and American A-TControls as high-end imported ball valves at premium prices. . . .

Materials, manufacturing processes, and design are the key factors behind the superior performance of imported products compared to domestic ones. Most domestic valves lack the durability and reliability of imported valves, even when priced at the same level as imported ones. Changhui Instruments yunrun.com.cn/

The prices of control valves from well-known domestic brands are also 2 to 3 times higher than those of valves from smaller manufacturers. For example, the Wuzhong valves I saw at the Sinopec plant in Renqiu were twice as expensive as valves from second-tier brands. Why is there such a large difference in prices? What is the reason again?

Domestic companies generally require low prices and high precision when making purchases; therefore, domestic valves are used while imported positioners are used.