Total Flooding, Local Application, and Engineered Systems

Posted by Lee Kaiser on Nov 27, 2017 5:07:05 PM

Knowing the different fire suppression terms, phrases, and keywords is one of the first steps in planning for a new fire protection system at your facility. In the video below, ORR Protection VP of Engineering and Fire Protection Seminar presenter, Lee Kaiser, explains what a total flooding system is, how local application systems work, and how to deal with uncloseable openings in your facility. He also explains the differences between engineered and pre-engineered systems and how they are used in different applications.   



Total Flooding Systems

Lee: "Total flooding systems versus local application systems. In a total flood system, we are going to fill a compartment with agent. Whether it's a room or a piece of equipment, we'll fill it from the floor to ceiling, wall to wall, with agent so that if the fire is anywhere in that room it goes out.

Local Application Systems

A local application is different. Typically we address a smaller area or piece of equipment inside of a larger volume with a local app-type system. Let's imagine that this table here where the projector is, is something to do with microchip manufacturing inside of a clean room. That piece of equipment is very expensive, and I want to protect it from fires.

I know that maybe some sort of flammable liquid that's used inside of it can catch on fire. That's the fuel source. I can use a local application, possibly a carbon dioxide system, to locally discharge carbon dioxide either inside or around that piece of equipment, inside of the larger room to control and extinguish the fire there. That's the idea of local application.

Uncloseable Openings

Another idea is uncloseable openings. Some suppression systems are fairly tolerant of leaky space, and some have to have fairly tight spaces that don't allow the agent to leak out of the room. Think about a room at a manufacturing facility that has some sort of process in it that you want to protect. In that room we're bringing in produce to process, do whatever we've got, and it's a conveyor that's bringing in that product.

As that conveyor goes through the wall, there'll be an opening. Right? And I can't put a damper or anything to close that opening. I just have to deal with that opening being constantly open. Some of the suppression systems we'll talk about are tolerant of those uncloseable openings, and some aren't. That's an important thing when making decisions about what type of suppression system to select.

Defining Occupied Spaces

Another set of terms that are important is the occupancy of the space and defining the occupancy. Normally occupied spaces would be like where we're at today. Places where humans are normally present and in that space, so we have to choose suppression systems that are safe for those spaces.

Now, it gets a little gray as we talk about the next two. Normally unoccupied space, a space that normally doesn't have anybody present. It's not like there's a desk sitting in that room where somebody goes to work, but someone could go in there to do maintenance or to check something out. I think about electrical rooms a lot like this, nobody really works inside of a switch gear or electrical room, but certainly can be present. It's meant to be occupied to work on the electrical gear that would be in that space.

For occupiable space, think about that as an enclosure. Maybe a piece of equipment that has a manway or a hand hole, some way that somebody can go in through a hole and do some maintenance on that piece of equipment, and so it is occupiable, but it's not occupied. In defining the hazard with regards to its ability to be occupied, it's important as we select a suppression system.

Engineered Systems vs. Pre-Engineered Systems

Finally we'll talk about engineered systems versus pre-engineered systems. A lot of the suppression systems that we'll talk about can be engineered, meaning that they need to have custom calculations run to size the piping and the nozzles for that specific installation.

You can also have systems that are pre-engineered, meaning that the manufacturer has done all those calculations ahead of time and included them in the manual. As an installer of that system, as long as you follow the requirements of the manual and don't exceed its limits, then you have a listed installation of that system. These different systems that we're going to talk about have different varieties of engineered and pre‑engineered systems."

Topics: Suppression, Nationwide

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