Are isolation valves required both in front of and behind the 8-character blind flange?
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Are isolation valves required both in front of and behind the 8-character blind flange? Are there any regulatory requirements?
Cut-off valves are installed in front of and behind the 8-character blind flange primarily for safety and ease of maintenance. It is determined whether shut-off valves should be installed on both sides based on the specific operating conditions as well as the safety and operational requirements of the piping system. Generally, to ensure the safety and reliability of the system, it is recommended to install isolation valves on both sides of the 8-character blind flange. To determine whether there are any mandatory regulatory requirements, it is necessary to refer to relevant industry standards or design specifications. .
8-character blind plates are usually installed and used in conjunction with isolation valves. The previous valve is usually normally open, while the subsequent valve is normally closed. It also prevents internal leakage from the previous valve to the downstream side during use.
There is no mandatory requirement, but having one at each end makes it safer and more reliable when switching the blind plate status.
There are no isolation valves installed either in front of or behind the 8-character blind plate； It is not possible to close when changing the direction of the 8-character blind flange, and thus the purpose of isolation is lost