Selection of cut-off valves and bypass valves for control valves

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Dear friends: Happy May Day. Holidays are the perfect time for casual chats and discussing issues. I have a question and would like to seek the advice of experts: in our projects, there are often control valves on the steam and water supply pipelines ； Each control valve is generally accompanied by three manual valves ； In front of and behind the control valve, there is a manual valve for shutting off the control valve respectively; in addition, there is a manually operated valve in the bypass of the control valve. Among the projects we have received, different design firms and designers have made varying choices regarding these three manual valves. In several projects, all three manual valves of the steam control valve are stop valves ； In several other projects, the three manual valves for the steam control valves are all gate valves made of cast steel. Shouldn’t the isolation valves before and after the control valve, as well as the bypass valve for the control valve, be of different types? ? After all, the bypass valve of a control valve is required to have manual adjustment capabilities ； The isolation valves before and after the control valve are used to shut off the pipeline only when the control valve is under maintenance; good manual adjustment performance is not required for them, right? Let’s discuss and offer suggestions; share your insights!