As we have discussed, the Chemical Safety Board (CSB) issued a Safety Study (CSB Safety Study: No. 2024-01-H, Remote Isolation of Process Equipment) discussing the untapped advantages when Remote Emergency Shut-Off Valves are used in hazardous processing. I have written about these requirements for all types of hazardous materials; this post is for Flammable Gases and Flammable Cryogenic Fluids.
A few months ago, I shared the requirements from NFPA 58 (LPG standard) regarding Emergency Shut-Off design options. Here is how the 2024 IFC dictates these requirements, with my comments to explain what it looks like in the real world…
5803.1.3 Emergency shutoff
Compressed gas systems conveying flammable gases shall be provided with approved manual or automatic emergency shutoff valves that can be activated at each point of use and at each source.
To maintain control over the flow of flammable gases under emergency conditions, each supply source, as well as each point of use of flammable compressed gas, must have an approved emergency shutoff valve. These valves must be excess flow control valves to regulate the rate of flow of hazardous materials within the piping system, fail-safe valves or other approved types that will operate automatically, or there must be a manual means of operation to give the fire department or other responsible persons the ability to stop the flow of hazardous materials in an emergency. The valves must be provided with ready access and comply with Section 5003.2.2.1.
5803.1.3.1 Shutoff at source
A manual or automatic fail-safe emergency shutoff valve shall be installed on supply piping at the cylinder or bulk source. Manual or automatic cylinder valves are allowed to be used as the required emergency shutoff valve where the source of supply is limited to unmanifolded cylinder sources.
Where the source of the gas is limited to cylinder sources that are not manifolded, the shutoff valve can be the cylinder valve itself. If cylinders are manifolded or if the source is other than cylinders, an independent shutoff valve is required to be installed in the piping system.
5803.1.3.2 Shutoff at point of use
A manual or automatic emergency shutoff valve shall be installed on the supply piping at the point of use or at a point where the equipment using the gas is connected to the supply system.
Emergency shutoff valves are to be installed on the supply piping either at the use point or where equipment is connected. Either manual or automatic valves are allowed to be used. For example, it is common in some installations to have gas piped to a room for use with portable or fixed equipment. Emergency shutoff valves are typically provided at the point where the piping first enters the room. Equipment may not be connected to the valve; however, the valve represents the point of connection for use. Where equipment is connected to the supply system, a valve that isolates the equipment is required. It may or may not be the same valve as that used at the point of penetration. Either valve is allowed to be manual or automatic, and either valve serves as an emergency shutoff valve.