Eric Johnson (00:02)
Welcome back, folks.
Eric Johnson (00:06)
Welcome back to Boiler Wild. My name is Eric Johnson. On this podcast, talk about boiler industry topics as well as personal development. I got a good technical one for you today. This is going to be a topic that a lot of people know about. But if you are new or if you are an owner operator, you may have not seen this done. If you have never had a new boiler, what I'm going to talk about is how to boil out a boiler.
Eric Johnson (00:35)
What is boil out and some other things that you need to know and why it's important. But first things first, thank you to everybody who's rated this podcast five stars. That really helps this podcast get found and helps the podcast platforms know that there are listeners. So if you haven't rated the podcast, please take a moment right now to rate the podcast five stars. It costs you nothing, but it means the world
Eric Johnson (01:03)
to me I greatly appreciate that. And if you want to leave a comment too, there's some comments on Spotify. I think you can comment on Apple Podcasts as well. Leave a comment too and if you write a question in your comment, I will reply to it. Or you can DM me on LinkedIn or email me, Eric.johnson at boilerin.com. All right, enough of that. Let's get into it. Right to it. How to boil out a boiler. First of all, why would we boil out a boiler? What is boil out?
Eric Johnson (01:34)
Boil out procedure is something that you need to do every time you have a new steam boiler, and every time, well, I wouldn't say every time, but most times that you retube a boiler or do a major repair on a boiler. So let's talk about the new steam boiler. So a new steam boiler is gonna be welded together and put together depending on whether it's a fire tube boiler or a water tube boiler.
Eric Johnson (02:02)
It is going to be put together with brand new metal and on a fire tube boiler, you're gonna roll a shell, you know, weld it on the tube sheets, and then put in all the tubes. Water tube boiler, you'll have a steam drum, you'll have a mud drum, and then you will form all the tubes. They'll all be bent forever for whatever the boiler design is, and they will get attached to the steam drum and the mud drum, however the design is. So
Eric Johnson (02:32)
Why is boil out important? So when you have that new boiler, it ships from the factory, and you may think, well, brand new boiler, it's clean and everything. Well, it's kind of clean, yes. But when you buy metal, when you are putting metal together, when you are rolling tubes and all this stuff, you are depositing some grease, you are depositing oil onto the metal and
Eric Johnson (02:58)
The metal has oils on it from just manufacturing shipping. It also helps it protect from like surface rust and everything. And the manufacturer typically does not remove that oil. What you would have to do is take acetone and wipe wipe down every tube. Or if it's a water tube boiler, you would have to like brush through every tube. But a lot of bending is done with a little bit of oil or everything, and that will get on the inside of the tube.
Eric Johnson (03:24)
And now you'll have a little bit of oil in your boiler. And you say, Eric, what's the big deal? What is what is a little bit of oil? So if you ever had a little bit of oil spill in your driveway and then it's rained, you may know that it looks like a rainbow and the oil is kind of floating on top of the water. Or if you are cooking and you put some water into a pot and then you put some oil into the pot as well.
Eric Johnson (03:53)
You'll pour the oil in and you'll notice the oil doesn't disperse, but it kind of just floats right on the top. That is because oil and water do not mix together. So if you pour like a Gatorade and water together, they're gonna mix together and you're essentially the water is going to become the color of the Gatorade because they are of similar substances. However, water and oil essentially repel each other and oil will end up
Eric Johnson (04:23)
Floating on the top. And that is why when you have a oil spill in the Gulf of America, you end up getting giant oil slicks that are floating around the Gulf that inhibit the wildlife, block out the sun, cause all the environmental damage, and that oil just floats on the top of the water and just goes everywhere. And that is how they do a lot of the cleaning: they skim the top of the water to remove the oil from the water. So
Eric Johnson (04:52)
You have your brand new boiler, and your customer may not be aware of what the startup is. This is part of startup, a boil out, and you may not be doing the boil out. Sometimes a chemical company will be doing the boil out if you are the startup company. Sometimes not. Me personally, I've always done the boil out. They are not difficult, but they can be done wrong.
Eric Johnson (05:19)
But I wouldn't say there's one right way to do it, but there's definitely a wrong way to do it, if that makes sense. I will explain that. So, oil and water do not mix. That is the important thing, and oil floats to the top. So, how does that impact steam production? So think about a boiler. Let's let's just think about a fire tube boiler. Everybody hopefully knows what a fire tube boiler kind of looks like in their head. And you have a normal operating water level that is going to be
Eric Johnson (05:48)
four to five inches above the tubes and go back to what I said about oil floats on the top. So all that oil that is on the tubes that is on the shell steel that the manufacturer manufactured that boiler with, that is all going to either stick to the tubes or it is going to eventually get scrubbed off the tubes and then float to the top of the water level.
Eric Johnson (06:17)
And if you were to pop open the manway of the boiler after you fill the brand new boiler, you would see rainbow on top of the water. And that rainbow is oil, and it's going to be a very, very thin layer. It's not like there's gallons and gallons and gallons of oil unless the boiler manufacturer did something wrong, but there shouldn't be gallons and gallons of oil. It's just going to be a little thin layer. However, that thin layer can cause chaos. And
Eric Johnson (06:46)
If you do not do a boil out, you typically can see a thin layer of oil in the sight glass, the water sight glass or the gauge glass that is coming off the water column, and you will see just like a little thin layer of something that doesn't look like water, it'll be a little bit darker, and then it'll get washed up on the sides of the glass if you have a tubular glass, and then it'll eventually come down and it'll always just be right on top of the water.
Eric Johnson (07:16)
So, how does that impact steam production? When you make steam, you have heat, and the heat is going through the tubes, and the water that is directly in contact with the tubes and with the furnace, the furnace is the large tube. It is also cord called a Morrison tube. Technically, a Morrison tube is only a furnace, which is what the the burner fires in, the large tube that the boiler fires in.
Eric Johnson (07:45)
The Morrison tube, some guy's last name Morrison, but he invented that furnace to be corrugated and corrugated has humps in it. Cleaver Bucks typically will use a corrugated furnace. You I think all boiler manufacturers will use them. There's benefits and drawbacks to corrugated furnaces.
Eric Johnson (08:10)
But the point is that you have a furnace and you have tubes. And the water will boil right at where the heat is. It doesn't just boil magically in the middle between tubes. It'll boil where the hottest parts are, which is the surface contact of the metal. And then the water continually cycles or circulates through the boiler internally. And that is called boiler circulation. And I will talk about that on a different podcast.
Eric Johnson (08:41)
So the water boils and turns into steam. So you get little steam bubbles. And that steam bubble, if you can imagine, you have a tube surface and you have water sitting against the outside of that tube surface in a fire tube boiler. And that water turns into a steam bubble, and that bubble rises up through the rest of the water until it reaches the top of the water level. That bubble, that steam bubble, will break through that.
Eric Johnson (09:09)
Top of the water level and enter the steam space of the boiler, and steam is a gas, and it will be part of that steam space. And if it is allowed to, if you have the valves open and if there is a pressure differential, the steam will flow out of the boiler. Going back to how it moves out of the water. So I want to highlight that the steam bubble rises up through the water and it will come through or break through.
Eric Johnson (09:39)
The water level. If you've seen a pond or you've gone to a small lake or something and you go to the edge of the water, or you you eat or even you can do this with a glass of water, that there will be surface tension. You can see surface tension. And if you go to a pond, you can see bugs walking along the top of the water. If you
Eric Johnson (10:03)
Slowly were to drop a penny on top of water, you can get a penny to float on top of water just because of the surface tension. So water has tension on the surface. That is a high school physics lesson. But the oil will increase that surface tension and it creates this layer. And what increasing the surface tension does is it allows that steam bubble to pick up water and bring water with it.
Eric Johnson (10:33)
So you just have this little tiny thin layer of oil, and all these steam bubbles are rapidly rising through this water that is in the boiler and breaking through the level of the boiler. And when you have a a layer of oil, that level increases with tension right on that layer. And now you pick up the water. And if you have a very mild boil,
Eric Johnson (11:00)
The water in the sight glass maybe just it'll just bounce a little bit and you maybe get a little wet steam. But if you're maybe in high fire and you're rapidly boiling a lot of water,
Eric Johnson (11:14)
The water level will pick up and you'll see in the site glass the water level just bouncing up and down, up and down. And what will happen is you'll eventually get it to bounce so much that it'll trip the primary low water cutoff, and the boiler will cycle, and obviously it will turn off. Well, hopefully it'll turn off, but it'll turn off and then it'll immediately restart again because the boiling will slow down.
Eric Johnson (11:41)
it'll understand that it does have a normal water level and it'll restart. And this cycle will continually repeat. You cannot boil off or just try to outsteam oil in a boiler. I have seen people try to do it. They try to skip the boil out step on a boiler startup and the oil just stays in the boiler. And you can't drain the boiler. You can't fill the boiler up
Eric Johnson (12:11)
with water and then drain it because the oil as the water level drops down in the boiler, the oil just clings to the metal surfaces. Oil is gonna have that tension and it clings to the metal surfaces and you'll drain all the water out of the boiler and you'll be like, Well, we washed it out. Nope. The oil is still stuck to the metal surfaces. If you work in the garage or
Eric Johnson (12:38)
You know, hopefully if you work in the boiler room or you've got an oil on your hands, sometimes you need a soap, like Dawn dish soap, in order to remove the oil and and it's not just water because a oil based substance such as just machine oil that is used for the machining of steel and all that stuff, cutting oil that is oil based versus
Eric Johnson (13:08)
What you would typically wash your hands with, which is just water. And that is why when you use special types of soap, just such as like Dawn dish soap, and this will also be a applicable when you are cooking oily foods. If you just wash your pots and pans with water, you'll kind of spread the oil around, you'll get the major food crumbs off the
Eric Johnson (13:34)
Pots and pans, but you won't really get the oil off. And it'll just seem like you're just kind of moving a mess around. And then you'll just put a little bit of dish soap in, and the dish soap helps to scrub off or remove the oil because of just essentially how the chemistry of dish soap is. And that's why you use dish soap instead of just hot water when you are doing your dishes. Side note, don't let your dishes pile up in your sink. Don't be a trash human.
Eric Johnson (14:04)
You should always stay on top of that. Anyways, back to it. So boil out, same thing with a water tube boiler. You have a steam drum and you'll be s having the normal operating water level in the steam drum, and all the oil from the tubes will be rising up out of the tubes and it'll be in the steam drum. Well, if you were to drain the boiler
Eric Johnson (14:28)
All the water would go out of the boiler, but then all the oil would get stuck to the sides of the steam drum and to the sides of the tubes of the inside of the tube since it is a water tube boiler, and you will not be able to clean out the oil. So, how do you clean out the oil? It is a procedure called boil out. And once again, I don't say there is a right way to do boil out, but there is definitely a wrong way. And the wrong way
Eric Johnson (14:56)
Is the number one wrong way to do a boil out is a time based boil out where and I've seen it where s a manager, maybe a project manager or even a customer, if you're doing a boil out and they say, do the boil out and do this for two hours and then that should be good. No, that is wrong. You don't know how much oil is inside the boiler, and you have to check. Boil out
Eric Johnson (15:24)
in a washout procedure of the boiler is a results based procedure. It is not a time based procedure. So if somebody says a boil out should only take four hours, that is a estimate of what they have experienced and it also based on the size of the boiler and if the boiler manufacturer wiped down tubes before they installed the tubes. There's a lot of variables to it. But
Eric Johnson (15:53)
Never ever say, well, it took more than four hours, so you did the boil out wrong. Boil out is results based, not time based. Very, very important. And if you skimp on the boil out and you just do a partial job, you will probably have problems and you'll eventually just have to redo the boil out. So it's best to just do it right the first time, as with everything. Always do it right the first time. So how do you do a boil out? So there's different kind
Eric Johnson (16:23)
Procedures. I believe ABMA has a procedure. Some boiler manufacturers, I think Superior Boiler just puts right in their manual the ABMA boil out procedure. I don't know who wrote that procedure for ABMA. I'm looking at a boil out procedure from Johnston Boiler that's right on their website. They are all typically the same. Once again, there's no right way to do a boil out, but there's definitely wrong ways to do a boil out. Every procedure
Eric Johnson (16:53)
From the manufacturer will be slightly different. If you have a boiler from a manufacturer, always look at the procedure for that manufacturer. But I wouldn't say that you would have to use that exact procedure versus another procedure because they're all going to be mostly the same. And the goal of every single procedure is to get the oil out of the boiler. So, how do you do that? One, you need to isolate the boiler from the system. So you're gonna have the header.
Eric Johnson (17:22)
Valved off, and you're gonna have all the drain valves closed. You are going to remove the safety valves. I have seen people do boil out by not removing the safety valves. I've seen people do boil out with removing the safety valves. The safety valves are typically, depending on how the boiler is built, one of the top parts of the boiler and
Eric Johnson (17:47)
Going back to what I said, oil floats on top of water. So the only way to get rid of it or to know that we're like flowing it out of the boiler is to take it off the top of the water. And how do you do that? Is to flood the boiler out of a top part of the boiler. So I'm not saying that you have to take the safety valves off, but it is recommended. It also is recommended to take the safety valves off so you don't get oil under the valves and under the seats.
Eric Johnson (18:15)
I will admit I have done boil outs where I have not taken off the safety valves. I've seen other people not take off the safety valves. Sometimes taking off the safety valves is a huge pain depending on how people pipe them. Sometimes pipe fitters will pipe safety valves and not put unions or flanges on the outlets of them. So essentially you have to cut everything and you would have to repipe it. And I understand that the world is not perfect. And you as a startup technician.
Eric Johnson (18:42)
Kind of just have to make do. So there's other ways to do it. You can find another plug. It all depends on the make and model of the boiler. Just talk to your boiler manufacturer if you are not sure on their procedure and if they don't put their procedure in the manual, or if you want to have a recommendation for that exact boiler model. So remove the safety valves, and this is also going to be your vent.
Eric Johnson (19:11)
So we don't want to build pressure when we are doing a boil out. All we are doing is gonna get all we're doing is getting a rolling boil. And a rolling boil is just gonna be a slow, gentle boil. We're not gonna be be building pressure. And that slow, gentle boil is just gonna be bringing up the water to 212 degrees, and it'll just all that boiling action will be removing the oil from the metal surfaces.
Eric Johnson (19:41)
And making it float to the top, and then as it's floating to the top and sitting there, then as we drain it out of that top of the surface of the boiler, we will be getting rid of the oil to drain. So you're gonna then after you remove the safety valves or other opening on top of the boiler, you're gonna fill the boiler with clean water and
Eric Johnson (20:08)
Then you're gonna put in the boil-out compound. There are chemicals that are specifically for boil out. I have heard of people using tide. I don't know if I would recommend that, but I guess in a pinch you can use tide. Tide removes oil from your clothes. It also removes oil from whatever it's put on. Tide is a detergent, just like your
Eric Johnson (20:36)
Dawn dish soap is a detergent. I would always use a boil out chemical that is meant for a boiler. And you also need to check if you have a site that is really specific about what is on site, what is what are the chemicals, what is going down our drain, especially if they have a wastewater plant. You want to be bringing in an SDS with the chemical, and you want to be
Eric Johnson (21:04)
Telling them what you are flown to drain so that they can be aware of that and to make sure that their wastewater is aware of that. Once again, it's not going to be a ton of oil. It's not just gallons and gallons of oil. It's just going to be a thin film. And most of the water that is going to be wasted is just going to be straight water. But you have to waste a lot of water in order to get the oil out of the boiler.
Eric Johnson (21:32)
So you're gonna add your boil out compound. Ask your chemical provider if you don't know what to use. I'm sure they will have a recommendation. If not, talk to your boiler manufacturer.
Eric Johnson (21:46)
You're gonna start the boiler, and this is a big one. If you have a brand new boiler, a lot of owners think startup is you walk in, you flip the on switch, and the boiler fires. If you've ever done a startup, that is probably not the case. With a steam boiler, there is a little bit more going on versus a hydronic boiler, and you gotta make sure that the gas pressure is correct, that everything is wired correctly. A lot of package boilers, even though that they're a packaged boiler.
Eric Johnson (22:15)
are not a hundred percent wired. So they may not be a hundred percent wired between the boiler and the burner, or you may have external wiring between the feed water pump and the burner, or the feed water pump and the low water cutoff, depending on your boiler setup. There's a lot of field setup and unfortunately also manufacturers make mistakes and you got to fix wiring mistakes for manufacturers because most manufacturers will just light off
Eric Johnson (22:46)
And do a test fire, but then they'll unwire, or they won't have the boiler 100% set up in their factory, they just make sure that everything works, but it doesn't exactly ship the same way that they're testing it. They're just testing function versus everything is 100% wired correctly, all the relays are wired correctly, and everything because I have found some mistakes that are like, How is this possible? Also
Eric Johnson (23:15)
If you read the manual, every manufacturer will say due to shipping and vibration, all the wires, you gotta check them all. I have
Eric Johnson (23:28)
not seen a wire come loose due to vibration from shipping. I've seen wires not even tightened and that is a little bit concerning, but it happens. I understand there's humans on the manufacturer side and those humans are also making mistakes.
