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Aug 29, 2022

This episode is a discussion about Fire Hydrants! Solocast 43 details codes, standards, and other criteria surrounding fire hydrants. Also we discuss hydrant components and the different types of fire hydrants that are common. 


Transcription: Speaker Gus

[00:00:00] 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 I.

Hello. All welcome to episode 43 of fire code tech. In this episode, we're talking about fire hydrants. Yes. I believe fire hydrants is a great topic for a solo cast because like many things that reside in the intersection in between two engineering disciplines, oftentimes they are forgotten or poorly designed.

So I'm talking about the fact that fire hydrants, although they are usually designed. [00:01:00] Located on the civil drawings have impact to fire protection features for the fire and life safety systems. So in these little nooks and crannies between disciplines, oftentimes we can find that projects either forget or, or neglect to give proper attention to these pieces of.

So, if you're still wondering, if you wanna listen to this episode, we're going to talk about codes, standards, and other criteria pertaining to fire hydrants. We're going to discuss the system architecture and component pieces of fire hydrants and the piping networks that they are attached to. And also we're gonna get into some key definitions for what a fire hydrant is and the different types of fire hydrant.

I wanted to take a moment and talk about the codes and standards up at the front of this episode. The goal of this episode is not to discuss the codes [00:02:00] and standards. I really wanted to just discuss some entry level topics. To establish what a fire hydrant is and some other parts and, and pieces of this piece of fire and life safety equipment.

But as a forward for the people who may have been listening to hear about more criteria or codes and standards around this subject, I'll start off with the codes of standards surrounding fire hydrants. If you're working in the us and you're using the international family of codes, you can look in the international fire code for additional code excerpts for the requirements for fire hydrants.

The section specifically in the international fire code 2021 edition is 5 0 7 0.5 0.5. This section is titled fire hydrant systems, and it is not very long. If you want to go brush up on these codes before you design a project, it'd probably be a pretty good idea. As the codes are always [00:03:00] a magnificent place to start to make sure that you are at the very minimum, getting the code required features that are in place in your project.

Second, let's talk about in the standards portion of the codes and standards discussion, where would you go to find out more criteria about fire hydrants? One place you could look would be N FPA 24, which is titled as standard for the installation of private fire mains and app. The chapter in specific where you can find information about fire hydrants is chapter seven.

Moving forward to the inspection, testing and maintenance criteria for fire hydrants. If you want to find this sort of information, go ahead and go look in N FPA 25, strangely enough. It, this is also in chapter seven, but the name of the chapter is not fire hydrants. Like it is in, in FPA 24. It is private fire service mains.

[00:04:00] okay. Just for a quick recap, we talked about the code section in the international fire code. We talked about the installation standard, which is N FPA 24. And then we talked about where you could find the ins the inspection testing and maintenance criteria, which is an FPA 25 as an additional point about criteria.

There is an appendix and fire code, which is appendix C. And this appendix is named fire hydrant, locations and distribution. Just a note on appendix material. You may know, but just worth saying in this discussion that appendix material is not always adopted. So you have to check your specific jurisdictional criteria to see if this appendix material is adopted and pertinent to the project that you're working on.

But it's good to know about the criteria into this appendix for best engineering practices. [00:05:00] Okay, moving on. I wanna talk about the definitions portion of this solo cast. So what is a fire hydrant? Maybe I should have put that first, but I'm gonna leave it here. Anyways. What is a fire hydrant? Let's talk about the definitions, which can be found in N F P a 24.

Hydrant can be found in the NFPA 24 chapter three. And it is defined as an exterior valved connection to a water supply system that provides host connections. So my 2 cents about this is that hydrants come in different colors, and sometimes they can be indication of different factors for the hydrant or for the facility, whether it be private or public.

Some of these factors may include how much water supply is available from the hydrant the water supply source in which the hydrant is fed from. And also it can just be a coloring or designation system for the facilities or base criteria. So there are two big, main types of hydrants. [00:06:00] One is a wet barrel, and one is a dry barrel.

I'm gonna talk about the definitions for both of these. Let's start off with dry barrel. Dry barrel hydrant is described in 3.4 0.1 0.1. And it states a type of hydrant with the main control valve below the frost line between the foot piece and the barrel dry barrel is the more common of the two hydrant types.

This is gonna be found anywhere in which you would normally have freezing conditions throughout the year. So in the majority of the us, this is what you're gonna find is dry barrel hydrants. Well, I bet you can guess what the next definition I'm gonna cover is that's right. It's wet barrel. And so this definition is 3.4 0.1 0.6, and it is stated as a type of hydrant that is intended for use where there is no danger of freezing weather and where [00:07:00] each outlet is protected with a valve and an outlet.

My piece of information on this we barrel definition would be that these. Hydrants are only common in very select pieces of the us think California and Florida in. ranges where the weather and or climate is exceedingly temperate or tropical almost. And so outside of the us, think of the Caribbean or other geographies that are near the equator, moving on, let's talk about the different component pieces of a typical fire hyd.

So we're gonna start off talking about the actual hydrant and then we will also discuss the piping and involving that leads up to the hydrant. So for a brief overview, before we dive into those different pieces, the summary of the pieces are the hydrant body. The stem nut or the operating portion of the [00:08:00] hydrant, the bonnet, the side outlet, the pumper outlet and the base flange.

Let's go from the top of the hydrant down to the base flange into the first piece we're gonna talk about is the operating stem and. This piece is on the top of the hydrant and it is how you open and close the fire hydrant. You can use a hydrant wrench to do this operat. Next piece we're gonna talk about is the bonnet of the fire hydrant.

Think of this as the round domed piece at the top of the fire hydrant, of course, there are some types of fire hydrants that will have different configuration that are not domed, but the top component of the fire hydrant, sometimes the hyd. Cap or bonnet can be a different color than the body of the fire hydrant.

So it's good to note these details. If you are doing a survey of fire [00:09:00] hydrant, or you are doing a flow test and you want to provide documentation of the hydrant in which you are activating, first outlet we are gonna talk about is the side. So there is the pumper outlet and the side outlet. The side outlet is one of the two outlets that are usually two and a half inches, two and a half inches is the standard hose size connection.

Another standard hose size connection is an inch and a half. The other connection is the pumper outlet. This outlet is usually four inches and you can hook the larger lines up to this outlet. I guess that makes sense. Since it's four over two and a half and one and a half, but you can get a much larger volume of water out of the pumper outlet, the flan or the base flan for the hydrant connects the hydrant to [00:10:00] the piping.

That extends all the way down to the elbow at the bottom of the hydrant stem only other component we didn't talk about for the hydrant in the actual, within the hydrant is the stem and the stem is what raises and lowers the plunger light device to allow the water into a dry hydrant. That is what operates when you are turning the stem and nut at the top of the top of the hyd.

Let's talk about the components that lead up to the hydrant and some of the piping and valving for a brief recap, we talked about the stem and nut, the bonnet, the side outlet, the pumper outlet and the base flan, as well as the stem within the hydrant. And now moving forward, we're going to talk about [00:11:00] the.

Gravel and drain basin, the thrust block, the control valve, and what the terms, lateral or branch line and service main or main or fire main mean in the context of a fire hydrant. First up is gravel and drain basin. This is the area in which the dry barrel hydrogen drains into the ground. Interesting note, you can put your hand up to the side of the side outlet.

If you have all the other outlets with their cap on them and feel the suction from the hydrant drain. If you've done a flow test and you are waiting for the hydrant to drain or verifying that the hydrant will drain. That's a good trick to know thrust block is a restraint or a restriction of the hydrant, and there is a calculation for how to [00:12:00] determine the size of the thrust block.

So that is something to consider. There are specific construction details for how these have to be built as well, the compaction and the aggregate and the concrete around the thrust block so that the pipe is restrained and supported correctly. Control valve. The control valve is required for the fire hydrant for you to be able to isolate the fire hydrant maintenance on the fire hydrant, or if somebody hits a fire hydrant with their vehicle.

So you can turn off the fire H lateral or branch line for a fire hydrant. This is the military refers to it as. Lateral line or a lateral service. So service lateral, think of this as the specific piping that serves the hydrant, not the main [00:13:00] that serves multiple hydrants. next is service main, main, or fire main, which this is the component that like the think of a sprinkler main, how it serves the multiple branch lines.

This is the same type of interaction in the piping system. I think that's gonna do it for this episode of fire code tech. Hope you enjoyed the solo cast. As an overview of the episode, we talked about hi, a highlight of codes, standards, and other criteria. We talked about some key definitions for fire hydrants last but not least.

We spoke of the parts and pieces of a fire Hy. Hope you enjoyed the episode 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 [00:14:00] 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. Thanks again, and we'll see you next time.