Nov 1, 2021
On this episode we are talking about water storage tanks for fire suppression. We go over NFPA 22 the standard for private fire protection water storage tanks as well as some common components of this system. The question of how to determine if a fire protection water storage tank is required is discussed at length.
Hello. Welcome to the solo cast of fire code tech in these episodes. It's just gonna be me, your host, Gus Gagliardi. There's gonna be a range of topics, but I'm gonna talk about specific technologies, installation, standards, codes, and how they work as well as some other interesting topics that don't neatly fit inside of the context of a normal interview.
Hello. Welcome to episode 20 of fire code tech. In this episode, we're talking about fire protection, water storage tanks. Yes. Last week we talked about water supply piping for underground Firemans. And this week I wanted to talk about another crucial component of fire protection, water supplies, which is storage tanks.
Don't forget to subscribe. So you never miss an episode and follow us on social media. Oh, and if you could do me a huge favor and give us a five star review on apple podcasts, that would help out so much. In this episode, I wanted to talk about fire protection, water storage tanks, because it's a complicated part of fire protection to understand.
We talked about fire pumps in episode number nine of the solo cast. And this is another big complicated component. Providing a water supply for, um, municipality that cannot supply the fire protection system in which you're designing. So one of the most critical pieces of determining if you need a fire protection water, uh, storage tank is by performing a preliminary hydraulic calc.
And we've talked a little bit about, um, the steps of that, what that looks like. And so this episode is going to expand on, um, after you've determined that you don't have the flow or the duration of water supply you need. Um, and you have decided that, uh, fire protection, water storage tank is necessary. Um, then what next, what code.
What standards, what are the pieces of equipment that are involved and, uh, much more so let's dive in. So unlike other fire protection systems, where you would take a look in chapter nine of the international building code, if you were trying to determine. The applicability of one of these systems to your building, um, fire pumps and fire protection, water storage tanks are a bit different in that they are required when the water supply of your municipality cannot sustain the, uh, fire suppression demand that is necessary for your facility.
So if you're working for a rural municipality, That has a four inch line with, you know, um, not much water supply and you're constructing a Highrise, or if you're constructing a building with high pile storage that is gonna have some significant, um, fire suppression demand, you might be in a situation in which you need a fire protection, water storage.
And so the codes and standards around this subject is, um, N FPA 22 is the standard that tells you the installation requirements of fire protection, water storage tanks. So there's not much in the way of the codes, the fire code, or the building code for fire protection, water storage tanks. At least not to my knowledge, I've done some research and tried to dig it up, but I couldn't find.
Um, any applicable sections? I'm sure there are some but nothing substantial. So NFPA 22 is the standard for water tanks for private fire protection. So this doesn't apply to the. Elevated municipal, uh, water tanks that are, uh, generally associated with public water supplies. These are fire protection storage tanks that are specifically for a suppression system on the premises.
Usually, sometimes these systems can also be utilized for hydrant loops. Um, if you're in that situation where you were referencing before. Where you have a very rural jurisdiction. Um, you might not have the underground fireman, um, size to sustain a hydrant loop either. So, um, that's a real possibility. So the majority of this conversation is gonna be around NFP 22.
There is no, um, there is not much building code and fire code information around fire protection, water storage tanks. It's all calculation driven. There are a variety of different methods for providing a fire protection water storage tank. You can, uh, not provide the entire fire suppression duration. Um, if you have the ability to.
If your municipal water supply has the ability to provide makeup, water, to accommodate the rest of the fire suppression demand. So say your total system demand is 400,000 gallons and you only provide, um, 300,000 gallons, but you've sized a, um, makeup, water supplies. So what that would look like is. A backflow preventer with an altitude valve that would have the ability to initiate when the water started to be utilized by the fire pump and then would make up that extra a hundred thousand gallons.
Um, you know, and that's not concrete numbers or a real example, but that is a common practice. So the size of year fire protection. tank is based on the fire suppression demand of your system tank sizes can range anywhere from 30, 40,000 gallons all the way up to I've seen million gallon tanks, the scope of NFPA 22 reads as the following.
This standard provides minimum requirement for the design, construction, installation, and maintenance of tanks and accessory equipment that supply water for fire protection, including the following gravity tanks, suction tanks, pressure tanks, embankment supported coded fabric, suction tanks, towers, foundations, pipe connections, and fittings, valve enclosures tank filling protection against freezing.
So this will give you a big picture of what N F P a tells you about the water supply for your fire suppression system. So this could be a storage tank for a sprinkler system or for a foam system or a water mist system. It really doesn't matter if this fire suppression system needs water. And your public water supply cannot, uh, sustain the demand that is required to install that system for the building and the hazard you have, then you need a fire protection water storage tank.
So what are some of the common components for a fire protection water storage tank? Well, you're gonna need control valves, a water level, gauge an overflow line. That is a line to where if the tank accidentally fills more than it's supposed to, the water will discharge a fill line. There's a variety of ways that you can design a fill line.
You can have an automatic fill line or a manual fill line, and that will impact your inspection, testing, and maintenance procedures. Depending on what part of the world that you're in. You might need a tank heater. There are a couple different ways that you can heat your tank. Some parts of the world. You might be able to just get away with insulating your tank, um, depending on the climate that you're in.
Otherwise, you will have to use a circulating, uh, or immersion. I forget what the two types of immersion are circulating type heaters. There's probably a good dozen steps in determining the volume of a fire protection water storage tank. And I don't plan on going over those in. Conversation, but I will try to write them out and go over them in a future lesson.
Um, you have to take into account the net positive suction head. You have to take into account the elevation differential between where your fire pump is and where your fire protection water storage tank is. You have to determine the, um, system demand. You have to take into account, uh, fill level and also where the overflow is.
And, you know, your monitoring points for your fire alarm system will correspond to, um, that minimum level in your tank that you need to have in order to supply your fire expression system with the duration of water that it needs. There are a variety of different materials that you can construct your tank out of.
Um, you could have a tank that is made out of steel and is welded together or bolted together. There are fiberglass tanks or, um, plastic tanks. If you will made out of composites, the layout of NFPA 22. Is similar to many other NFPAs, as we always talk about the first four chapters introduction, reference publications definitions in general information.
Um, and then as you move on through the standard, there are different chapters for the different construction types and, um, types of water storage tanks, uh, welded steel. Bolted steel pressure tanks, wood tanks. Um, this is a one that I, chapter nine is one I'm not real aware of embankment supported, coded fabrics, suction tanks, concrete tanks, fiberglass tanks.
And then when you get to chapter 12, um, it talks about foundations. Usually the foundations a is. Either determined by a structural engineer or a delegated design from a structural engineer. Chapter 14 is pipe connections and fittings, chapter 15, valve enclosures and frost protection. There are different configurations that you can have.
You can have your tank, um, not attached to your pump building. You can have your tank effectively, um, adjacent or connected to your fire pump building. Um, you need to be careful because there's gonna need to be some kind of freezing protection. If you have your, uh, fire protection, water storage tank, um, remote from your pump building, cuz those valves are gonna need to, before they can go underground, have a place to come out of the side of the fire protection, water storage PLA tank.
So you'll have to heat that enclosure that wrap up our first conversation about fire protection, water storage tank. Thank you for listening and we'll see you next time. Thanks for listening everybody. Be sure to share the episode with a friend, if you enjoyed it, don't forget that fire protection and life safety is serious business.
The views and opinions expressed on this podcast are by no means a professional consultation or a codes end standards interpretation. Be sure to contact a licensed professional. If you are getting involved with fire protection and or life safety. Thanks again, and we'll see you next time.