Engineered Corrosion Solutions: The Case for Automatic Air Vents

Posted by ORR Protection on Mar 15, 2021 9:30:00 AM

Bill Aaron, Director of Training at Engineered Corrosion Solutions, makes the case for the use of automatic air vents for NFPA compliance and to reduce corrosion by removing oxygen molecules.

Wet Pipe Venting and WPNI

 

Video Transcript:


The ECS automatic air vent uses a redundant float assembly that does not require piping to a drain. If you look at it, we have our connection to the sprinkler system. From there, we have a bowl valve that can be used for maintenance and or servicing or installation from there a quick disconnect, quick disconnect. You can take it apart, put it together without having to drain the sprinkler system. From there, we have a why to protect against any contaminants that can get into the float. Assembling as air as, as the sprinkler system is filling the air would pass through up into the first float from the first float. It will go through the intermediate chamber to the second and exhaust out when water reaches up to the first float, the first float seals and protects the spring sprinkler system from leaking. If there's any contaminants that get past the why strainer to cause the first float not to fail the then water would then go through the intermediate chamber up to the second float to protect you, protect against leakage. The other thing that's included is a gauge and should the first float fail this. And the second float is used to protect the system. The gauge would give you a gate, give, give you a reading that you can read from the floor to identify if you need to do any servicing. So from inspection purposes, all you need to be able to do is be able to see this gauge, to determine if the automatic air vent is working
properly.

When you start thinking about getting air out of a sprinkler system, what are we actually doing? Well, if you think about the fact that our corrosion activity is at the air water interface location, it's not at the fluid packed. It's not at the air pack. It's only the locations where there's a combination of oxygen, water, and steel, and you put a vent on it and you're reducing some of that trapped air what's happening is your changing the location of the air water interface to new pipe. By doing that, what you've done is basically doubled the life of that sprinkler system. You haven't stopped the corrosion activity, but what you have done is moved the location of the corrosion to a new location, which means the process starts over again because remember corrosion activity is cumulative is going to continue. Same time after time after time.

Now, why do we need to put an automatic air vent in what's the purpose of it? Number one, NFPA 13, the 2016 edition requires us to do that. Now remember too, just because NFPA 13, the 2016 edition is requiring us to do it. It only happens when the local municipality has adopted the 2016 edition or higher edition of the code. If they have not adopted it yet, then there is no requirement. However, if they haven't, you know, sooner or later they will, and when they do, you're going to have to install these. The other thing it does reduce the total corrosion that takes place because you're removing some of the, the trapped oxygen out of that sprinkler system. And the more oxygen molecules that you can eliminate the better off the less corrosion you're going to have. The other thing to install a vent on a sprinkler system is relatively inexpensive.

It's easy to install. And if, you know, if you looked at it from the contractor's cost is labor plus the vent, you're probably looking at less than $2,500 to do that from an ease of installation, all they need to do is drain the sprinkler system down, install a mechanical T on a high point on the system. The vent installs into it. It connects through a half inch mechanical T MPT thread, and you're done. The vent assembly itself is light enough. Doesn't require hanger. If you want, you can add it in, but it really doesn't require. The other thing. The redundant design means there's no plumbing to a drain, no additional piping that needs to be done to get, to get the, the potential of leaking water outside the system because of the redundant float assembly. We have not ever seen one of these fail.

So you have the protection. The entire vent assembly is FM approved. And as you all listed, it's not just a portion of it. That's FM and or UL. Listen, it's the entire assembly. Now the other thing, the ejector automatic air vans can be upgraded for nitrogen and inerting. And we're going to talk about nitrogen inerting in just a few minutes, but if they are easily upgraded, here's a recommendation. Whenever you're working on a wet pipe sprinkler system, for any reason, install an automatic air vent, you've already got the system drain down you've you don't have any additional costs. All the labor that the lifts and everything else are already there, all you have to do is add the vent in, and you've extended the life of the sprinkler system for the customer. Now what's the difference between an air vent and wet pipe, nitrogen and nerdy.

Well, as we've been talking about air vents, remove some of the oxygen that causes corrosion in that trap. There, it doesn't stop corrosion and only reduces it because you're only getting out some of the air, not all of the air now wet pipe, nitrogen, and inerting is a process. It's an event where we remove all of the oxygen and we replace it with nitrogen gas. Nitrogen gas is an inert gas, and therefore there's no correct corrosive activity to it. And it completely stops the corrosion process in the system. Now, if you're going to wet pipe nitrogen, every system, there are three things that you have to have. Number one, you've got to have a source of gas. The standard practice is to use nitrogen cylinders because they're relatively inexpensive. However, if you get into a large facility or a facility where they're doing a lot of work on a lot of sprinkler systems, there may be alternatives to nitrogen cylinders.

You might want to consider a large nitrogen generator. So you don't have to worry about the safety issues of handling those cylinders or the space that's needed. The other thing you need, as you need a removal van, you've got to have a way to get the oxygen molecules out of the system. The third thing is you've got to have a protocol. You got to have a method on how you're going to do it. The process itself is fairly simple. It's a three-step process where we drain the sprinkler system. We fill it full of nitrogen three times and exhausted, and then we fill it back up. It's a very easy process and event it's not continuous. And then once you've completed it, all you have to do is do everything as you normally have before. As long as you're flowing water, there's no issues. It's only if you have to drain that sprinkler system.

Is there anything different that you have to do now? The wet pipe nitrogen inerting vent is similar to the standard vent. It is lightweight. It only weighs about 10 pounds. It has the gauge where you can see it from the floor. If you can see if the primary float has failed, it is the complete assembly is UL listed. There's no an FM approved. There's no requirement to pipe it to a drain. The finger remember is that this is a manual process where we're using nitrogen gas to remove the oxygen. And any gas is left in the sprinkler system is non-corrosive. Now we've done a lot of, we've been doing the nitrogen inerting for over 10 years. And here's a case study. This is a big box store that they had 19 events. They spent close to $40,000 in repairs since 1994, the wet pipe nitrogen learning process was completed in March of 2016.

They have not had any leaks since, and they did not replace any pipe at that time. Now in this picture, you can see the picture on the left is untreated water. This is what we're used to seeing out a nasty old black sprinkler water. The picture on the right is what it looks like after it's been nitrogen and nerdy, because the thing is, if there's no corrosion activity, there's no way for the color, the water to change colors. If the no water doesn't change colors, it comes out as clean as it went in. Now here's an actual video of them draining a sprinkler system. And by the way, they filled that water glass up with the water from the sprinkler system. I can't tell you if they drank out of that water glass or not, but it went in as clean as it, as it went, as it went in. And it did not stink now. So what did we learn today? Well, we've learned that number one, oxygen is the primary cause of corrosion and fire. Sprinkler systems. Number two, black steel is better than galvanized pipe for sprinkler systems. Number three, corrosion occurs at the air water interface on high points on wet pipe, sprinkler systems. Remember you got to have the combination of oxygen, water, and steel, all in the same locations. Number four, wet pipe, nitrogen and nerdy removes all oxygen from the wet pipe sprinkler systems.

We really appreciate your time for being with us today. If you have any questions, please call us or go to our website at ecscorrosion.com. There's a lot of information. There's case studies. There's white papers, a lot of information that's available to you. Please let us know if you have any questions and again, thank you for your time.

Topics: NFPA,, Corrosion, Featured Article, Video Blogs, Featured Blog, MCFP

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