【Process Area Event – Bizarre Designs – 11】-- Problem with the control valve bypass
Thread Content
The valve shown in the diagram is a field control valve, through which media such as process gas, nitrogen, instrument air, water, steam, methanol, hydrogen, etc., flow. May I ask: Is it okay not to install a bypass for the control valve? Are there any relevant standards? (How to handle control valve failures)
Bypasses should be installed from the perspectives of maintenance and operation.
More pipelines mean a higher risk of leaks; they can also be omitted
Such situations are common on site; bypasses are not provided mainly for process and safety reasons as well as to facilitate online maintenance. If the control valve fails, it has no impact on the entire production process; for models that require shutdown for maintenance, other controls can be used without the need for a bypass.
It would be best to point out the unreasonable parts; I’ll wait and learn*:lol
It should be designed so that the machine stops in case of a failure – how great will the losses be?
If closing some valves for a period of time has no impact on the process, it is not necessary to use a bypass
If there are no safety issues with cutting it off, it can be omitted. However, this factory’s insulation and protection measures are really poor, and there’s too much dust and dirt around – it’s a very poor-quality factory
I’ve seen ones without bypasses, though they are relatively rare. I don’t know what the regulations specify.
For easy maintenance, a bypass is provided, with valves installed before and after the control valve.