What is the difference between valves

They are all the same. Z41H-25 becomes SHZ41H-25 product name after adding SH written in Shanghai in front of it.: Gate valve product model: Z41H Origin: Shanghai details: 　 　　The gate valve is one of the most commonly used cut-off valves. It is mainly used to connect or cut off the medium in the pipeline. It is not suitable for regulating the flow of the medium. The gate valve is applicable to a wide range of pressure, temperature and diameter, especially suitable for medium and large diameter pipelines. 　 　　The main advantages of gate valves (1) The fluid resistance is small. The internal medium channel of the gate valve body is straight. The medium does not change its flow direction when flowing through the gate valve, so the flow resistance is small. (2) It is more labor-saving to open and close. When opening and closing, the movement direction of the gate plate is perpendicular to the direction of the medium flow. Compared with the stop valve, the opening and closing of the gate valve is more labor-saving. 　 　　(3) The flow direction of the medium is generally not restricted. The medium can flow in any direction from both sides of the gate valve, and can be connected or cut off. Easy to install and suitable for pipelines where the flow direction of the medium may change. 　

That's not necessarily the case. Why isn't it the abbreviation of "Petrochemical"? SH

I think SH should be interpreted as a petrochemical standard.

Is there any company now that manufactures valves specifically for a standard? Like the Fisher brand valves I make, they all pass API and so on. ； What you mean is that it can only be used in petrochemicals and not other places? And you have seen the valve introduction I gave, if it really marks the suitable range, that would be it.

However, the application medium is also taken into consideration when designing the valve.

They are all the same, Z41H-25 becomes SHZ41H-25 after adding SH written in Shanghai in front of it: lol It is imaginative and awesome, it is really awesome!

sh should be the manufacturer's self-numbering. Nowadays, many manufacturers add self-numbering on the front in order to show that they are different from other manufacturers.

sh should be the manufacturer's own number, I agree with the opinion above.

The petrochemical industry has specialized valves. Some pipeline standards in the petrochemical industry are different from ordinary chemical pipelines.