Seeking experts with experience in designing valves such as control valves

Answer each question one by one: 1. Is the valve a standard component? Ordinary valves such as gate valves and globe valves are definitely standard components, which enables their mass production in bulk. Items such as control valves that require separate calculation are not considered standard components; they need to be manufactured using custom molds. 2. Why are there standards for valve components such as packing glands, bolts, nuts, and valve stem nut washers? There must be standards for this; without standards, does that mean that each valve manufacturer can design its components freely? How can the quality and interchangeability of these components be ensured? 3. Should the valve design be based on standards or designed freely? For small and medium-sized factories, they definitely follow the standards. If it is a large company with strong technical capabilities, it can design its own solutions, as most standards are developed with the involvement of leading enterprises. But there is no freedom to design; any design must follow a method

Thank you very much; that makes a lot of sense! It resolved my doubts. There is another question: if a packing seal is required for the shaft of my simple control valve, and given that the inlet gas pressure is 10 Mpa at room temperature, should the packing seal design be chosen in accordance with the standard KB/T 1708-2010? Which standard should the structure of the corresponding stuffing box follow? If anyone upstairs is aware of this, please offer some guidance. Thank you!