Storing Compressed Medical Gas Cylinders
by Brad Keyes, CHSP, on Sep 4, 2020 1:00:12 AM
Q: How many E-cylinders are permitted per smoke compartment and do "partials" count as part of the quantity?
A: Basically, you can have an unlimited number of ‘E’ cylinders per smoke compartment, but depending on the quantities of cubic feet of gas that you have, there are different requirements to store them. ‘E’ cylinders contain 24 cubic feet of compressed gas when full, so you may have up to 300 cubic feet of compressed gases stored anywhere in the smoke compartment, and it is unregulated, as long as the cylinders are secure and the do not obstruct the required width of the corridor. Twelve cylinders equals 288 cubic feet, so you can have up to 12 ‘E’ cylinders without having a designated space to hold them.
But once you reach 13 ‘E’ cylinders (312 cubic feet) in a smoke compartment, now you must store them in a designated room that is made with non-combustible (or limited combustible) materials and equipped with a door that has a lock on it. In this room, the oxidizing gas cylinders must be kept a minimum of 20 feet from combustibles, or 5 feet if the room is protected with sprinklers. Once you reach 3,000 cubic feet of compressed gas stored in a single smoke compartment (125 ‘E’ cylinders, or a combination of ‘E’ cylinder and ‘H’ cylinders, which contain 250 cubic feet of compressed gas), then you must store them in a designated room that is constructed with 1-hour fire rated materials, has a dedicated mechanical exhaust system, and a few other requirements.
Not only do partials count as ‘full’ cylinders for calculating stored quantities, but so do empty cylinders. Most AHJs will consider an O2 cylinder that is marked ‘empty’ to contain some level of compressed gas, but how much? That is unknown, so most AHJs will consider an empty cylinder the same as a full cylinder when figuring the quantity of stored cylinders.