Issues with the SIS shut-off valve installation at the tank inlets of the liquid chlorine storage area
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The liquid chlorine storage area contains multiple liquid chlorine tanks, and each tank is equipped with a DCS isolation valve. The entire storage area constitutes a major hazard source of level 1; according to Order No. 40, an independent SIS system is required. Is it feasible to install SIS isolation valves on the main feed pipes for all the tanks? Is it still necessary to install SIS shut-off valves at the inlet of each storage tank? Is there any relevant evidence?
It’s a SIS system designed for you to use alone
It should be entered into the SIS system; the risk level is very high.
What is the reason for installing SIS valves at the inlet of each storage tank?
There are numerous regulations, norms, and standards issued by the State Administration of Work Safety regarding the safety management of major hazard sources and hazardous chemical storage areas, on-site safety monitoring in such areas, as well as alarm and interlock systems; they will not be listed one by one here. Simply put, the reason is this: without a separate SIS system and shut-off valves, a safety review cannot be passed, and a safety production license cannot be obtained. Then who will be held responsible for illegal construction and production?
In one of our projects, the SIS valves are installed on the inlet pipelines of each liquid chlorine storage tank. When Donghua Design Institute conducted a diagnosis of our project in July this year, it suggested that the SIS valves could be placed on the main pipeline. If one is installed on the inlet pipeline of each liquid chlorine storage tank, it represents a somewhat transitional design; currently, we have multiple hydrogenation reactors in the same area, and the SIS valves on the hydrogen inlet pipelines are also located on the main hydrogen pipeline.
Systems with a SIL rating of 1 or higher must be integrated into the SIS system. It is reasonable to install level interlocks for liquid chlorine tanks on the inlet and outlet pipelines of each tank; if such interlocks are placed on the main pipeline, then in the event that the level in one of the liquid chlorine tanks is high (or due to incorrect readings from the instruments), the SIS interlock will shut down the main valve, which could severely impact safe production.
This SIS shut-off valve can be installed on the main chlorine inlet pipe, set to the normally open position, and interconnected with alarms for pressure, liquid level, and abnormalities in each storage tank! If possible, I can send you a separate SIS setup screen. Each tank is equipped with a separate DCS isolation valve and a separate level pressure interlock.
Each storage tank forms its own separate circuit and must be installed on a branch pipe. First, there is a common cause of failure in the main pipeline; second, it is necessary to clarify the permissions for DCS and SIS.
Everyone who replied to my post is here; I suggest placing the SIS shut-off valve on the branch line: lol