Sunday, January 21, 2007


People say I’m stirring things up with talk about exploding chlorinators. They say, "Chorinators don’t explode!" They say, "Cite me one instance of an exploding chlorinator!"


The thing that got me writing about exploding chlorinators to begin with was a conversation I was having with a prominent custom pool builder in California who had first hand experience with exploding chlorinators. We had been talking via e-mail, and I mentioned my blog. He wrote back:

"I ... found your blog and ... read four or five posts. Interesting stuff, most of which I agree with. I try to steer my clients away from salt systems for some of the reasons you've mentioned. To me it's just not worth it to make a couple of hundred bucks, but have a client referral go bad because they're not happy with their $1200 system -- a system whose reality doesn't even come close to the what the local salespeople trumpet. Hey, all my business comes from referrals, so I've got to tell them all the truth. Best policy in the long term. And I had a bad experience with the one salt system I've used this year (client insisted on having one): pool one month old, plumbed in salt system, added salt, system exploded -- literally -- two days later. Big boom: pieces of 3-in. pipe (rated at like 280 psi) shot over fifty feet away. Manufacturer had engineers, sales reps, field techs, whole works out there. Tried to replicate in lab with no success. Still don't know why it happened; just glad client not in vicinity when it happened. Needless to say, I'm a little gun-shy now."

I responded:

"...what happened to you is another stellar example of why we need to stamp out salt systems. It sounds like you had a buildup of hydrogen gas in the cell or in the plumbing. That will occur if there is power to the salt cell when there's no flow. The flow sensor is supposed to shut everything down, but if it doesn't, then that can happen. They know what caused it, but they'll never admit it. ... The way that the manufacturers and the reps keep us in the dark is by sending a bunch of people over to ‘investigate the problem’, stand around and scratch their heads for awhile, swear that it's never happened before in the entire history of their corporation, and then leave. It's an isolated incident until a guy in California (that would be you) is on the internet talking to a guy in Texas (that would be me) and that's why I love the internet. And that's why I think there's hope for our industry, now that pool guys can communicate outside the sales & marketing drenched environment of trade shows and trade organizations."

He wrote back:

"Neither the manufacturer nor supplier had ever heard anything like that happening. I believe the supplier, but the manufacturer . . . No explanation was offered, though I speculated initially about the possibility of hydrogen. You know -- anode and cathode in water, water splits into H2 and O2, the ingredients of an explosion. The engineer from the factory was, or appeared to be, baffled by the chemistry. Looking back, that seems odd, since he has a degree in mechanical engineering which would probably require at least a few chemistry classes. Anyway, they took the chlorine generator back to check it in the lab. They also tried to replicate the conditions at my client's pool, but couldn't get anything to explode."

It’s like Men In Black, where the Guv Guys come in and clean up the scene, then nonchalantly slip on their Ray Bans and then hold up the little Forget Everything Thingie, and POOF, it never happened.

I wonder how many exploding chlorinators do we not hear about because, "Gosh, this has never happened anywhere in the entire history of the free world and... Sir! Step away from the computer! Don’t Google hydrogen gas buildup and chlorine generator. Look over here. See the pretty light?"

This builder has asked me to allow him to remain anonymous for pretty much the same reason that I write this blog anonymously; we both need to keep making a living. Now, some will say that I just made all that up, because it is a textbook example of what I was talking about two posts ago. But that’s because that blog piece was written during these conversations with Prominent Custom Builder, California.

And did I nail it? When I said that the "way that the manufacturers and the reps keep us in the dark is by sending a bunch of people over to ‘investigate the problem’, stand around and scratch their heads for awhile, swear that it's never happened before in the entire history of their corporation, and then leave". Even down to the mechanical engineer acting like he’d never heard of the possibility of hydrogen gas buildup.

Because you know that if that builder had installed it wrong, those engineers and sales reps and field techs would have been the first to point out to him that it was His Fault and What Was He Thinking? and Do You Know What Could Have Happened If A Child Had Been Standing There?

You know they would have. And then they would have winked and told him, "It’s okay. We’re you’re friends. We’re going to take care of you on this one. But some day, and that day may never come, but some day I may ask you to do me a favor..."

Leave the gun. Take the cannoli.

But, like I said, if you think I made this up, then it’s no proof that salt chlorine generators blow up.

So, how about this?

It’s a page on the Chemical Accident Reconstruction Services, Inc. website, about a hydrogen explosion investigation. This accident happened at a water treatment plant that was using electrolysis to generate sodium hypochlorite from sodium chloride. Sound familiar? Sound like something going on completely unattended each day in your back yard? But don’t worry. I’m sure your salt system is much safer than the ones they have at an industrial water treatment facility. The investigation report clearly states that one "of the disadvantages of the electrolytic process is that hydrogen gas is also created as a byproduct", hence, in this case, an explosion.

Don’t take my word for it. Paste that link into your browser and go read it for yourself.

Still don’t believe me? Here’s a cute video of a fifteen year old kid on YouTube who does a science project where he puts two electrodes into a plastic bottle, fills it with salt water, hooks it up to a 12-volt battery and then within a few seconds after putting the power to it, lights the hydrogen gas on fire with a kitchen match. It’s actually more of an explosion, as it flairs and goes out. A little bit longer under pressure though, and it would have exploded all by itself. As you watch this video, notice how much that plastic bottle resembles your salt cell, and how much this experiment resembles the experiment you’re conducting each day with your salt system.

Please! If you don’t follow any other link off these pages, paste this one in your browser and go watch it. More than all my words, it illustrates the potential for fire and explosion that is part and parcel of working with hydrogen gas.

This next one is from the Department of Minerals and Energy, Western Australia. It’s a summary of accident reports from 1997.

It says:

"The most significant incident for the year occurred at the Fremantle Leisure Centre where a hydrogen gas explosion forced the evacuation of approximately 600 people from the premises during the busy summer holiday period. The chlorination plant has been rebuilt and the design fault that caused the explosion has been corrected."

That happened on January 16th, 1997, to be exact. I found another reference to it on the web here:

Notice that the name of the pdf file is also the date it was published. It was such a big deal they were still talking about it five years later on it’s anniversary date. But I guess any time you have to evacuate 600 people because of a salt chlorine generator explosion, you would talk about it for years. Here’s what they were saying in Australia, the home of salt chlorine generators, five years to the day after the explosion:

"The Department is also urging operators of swimming pools with salt-water chlorinators to ensure the hydrogen produced from their electrolysis units is safely discharged.

‘Make sure the storage treatment room is ventilated and not located near a potential ignition source, as we don’t want to see a similar incident to that which occurred at the Fremantle Leisure Centre in January 1997,’ Dr Drygala said. ‘Investigations into that incident revealed the explosion was caused by hydrogen gas igniting inside the plant room’."

There’s one more incident and I think it’s just hilarious. I mean, as hiarious as potentially life threatening explosions can be. Right now, it’s still just a story someone told me. He wasn’t there at the meeting to see it happen. I’m waiting for a couple of phone numbers so I can report it with names and dates and such like that. But in the meantime, it’s a great story, and since it may be awhile before I get back to the subject of exploding chlorinators, I might as well toss it in.

A Sales Rep was giving a product demonstration for an "in-deck" salt chlorine generator at a large pool construction company. I’ve only found one in-deck system on the internet, but until I hear from someone who was there when it happened, I’m not going to name names, just in case there’s two in-deck systems that can blow up. Now, this pool construction company's plaster consultant had told them that they ought not to buy the in-deck system because the system operated even when the pump was turned off, which meant no water flow through the unit, and therefore, there was a potential of the hydrogen vent being blocked by something as simple as a pool toy - gosh, I never see those in a pool. Do you? - and someone with a cigarette or a flame source causing a fire or explosion if the lid were to be opened for service or checkout. So, the President of this pool company asked the salt system Sales Rep if it was possible for it to happen. Of course, the Sales Rep started right in ripping into the consultant’s credibility, telling everyone there, "Aw, the guy’s a crackpot. He just hates salt. Who you gonna believe, a guy with a tech library bigger than my house? Or me, a recent graduate of the LaSalles Institute’s School of Business and Locksmithing?"

It is ever thus when you’re talking to Sales Reps. You’re either afflicted with an afternoon of tear stained pleas of, "Oh, God! Please buy my product!", or they go right for the jugular, disparaging anybody with an opposing point of view, especially if that opposing point of view is based on something as trite and meaningless as "facts" or "independent research" or "government initiated accident reports".

Anyway, the bottom line is the Rep said, "No way can this thing explode", turned on his demo unit - which must have consisted of the unit set up in a tank of water- and lit a match to prove how wrong the consultant was. There was a blinding flash as all the accumulated hydrogen gas went up in a big POOF. No one was hurt, but needless to say, the pool company didn't buy the in-deck system.

Now, I have tremendous professional respect for the person who told me that story. And I was introduced to that person by someone who I have even more respect for. I believe it happened just like that.

Of course, at this point, the folks on the Dark Side will say that, gosh, there’s plenty of other stuff that can blow up out there on your pool equipment pad. Well, that’s great logic. Let’s add one more. But to be fair, let’s look at the competition for Most Explosive Device In Your Back Yard.

Like your pool filter. It operates under pressure. Make a mistake while you’re working on it and the top could come flying off and rip off your face, at the very least, and kill you at worst. And in the past, that’s happened more often than I like to think about. When I first started in this business, back yards were full of aging stainless steel filter tanks with these minuscule little lips on the tank halves that these skinny tank bands held together with a little old 1/4" nut and bolt.

But these days, it’s a different story. Those tank halves have big old seating surfaces, and the tank bands are thick and heavy gauge, with big old bolts with tons of threads on long fasteners to make sure that a thread failure is a literal impossibility. They even have springs to show you how tight to tighten the tank band clamp so it’s not too tight, not too loose. And on the off chance that you’re from Mars and didn’t realize that you ought to turn off your pump before you start to take your filter apart, there are huge warning labels that explain in big bold letters how dangerous that filter tank can be if improperly serviced. They even have cartoon pictures of cartoon people getting hit in the head with cartoon tank lids just in case the person trying to take it apart can’t read.

You know, people had to die to get those improvements in filter tanks and to get those big old warning labels. When it became cheaper to build a better and safer filter than it did to keep paying off on all those wrongful death suits, they started building better filter tanks.

So, where’s all the warning labels on the salt systems? We already know they can blow up. How come these guys don’t have to put any labels on them? I mean, we know now that electrolysis is a dangerous process. So what’s up?

I guess the cost isn’t high enough yet.

Then, too, you have a heater out there, and it doesn’t have near as many warning labels on it as your filter does. And it’s got a gas line going into it. Gas is flammable AND explosive. But then, is there anybody left on planet earth who doesn’t know that gas is explosive? I bet not.

On the other hand, did anyone along the way, in the process of your salt system going from an idea in your head to an appliance in your back yard point out to you that there was an explosion risk with your salt chlorine generator? I bet not.
The other day I was talking to a pool guy who works for a service and repair company that fills in the slack times by signing up to do warranty work for as many of the equipment manufacturers as they can. In our conversation we got around to talking about salt.

He said, "When I was in the Navy, I used to ride submarines, and we used to practice responding to different disasters. Like a fire, or flooding, stuff like that. And one of the most common drills we used to run was fire in the Machinery space and it was always the O2 generator that they were pretending was on fire. And if we didn’t pretend to get the fire under control fast enough, then we’d pretend it exploded, and then we all pretended we died."

Submarine O2 generators make oxygen out of seawater through the process of electrolysis.

But I’m sure the United States Navy Nuclear Submarine Force is exaggerating the potential risk. I’m sure your salt system is 100% safe and can never explode. I’m sure it’s built to the same exacting specifications as those SUBSAFE Oxygen Generators.

And if you have any doubts about that, just ask your Salt Sales Rep. He wouldn’t lie to you. He’s your friend.

One last thing to contemplate. All the references I've cited are either conversations I've had with people it happened to or heard of it happening, and the rest are from government reports or stories about government agencies where these kinds of things are routinely reported and publicized. Ask yourself this; If a chlorine generator blew up two streets over from your house, what mechanism is there for it to be reported?

The only one I can think of would be the manufacturer's internal reporting. Follow me here. Your chlorinator blows up. You call your pool guy who sold it to you. He calls the manufacturer. The manufacturer comes out with a bunch of people to "investigate the problem". They stand around and scratch their heads for awhile, swear that it's never happened before in the entire history of their corporation, clean up the mess, give you a brand new chlorine generator and then leave.

That's it. And based on that kind of incident reporting, I'd have to agree that chlorine generators never blow up. Wouldn't you?


rbtempe said...

Wow great information, I have a salt/chlorinator and it exploded just this past Thursday evening. This it the second time in 18 months. Of course manufacturer and pool store all act as if it can't happend and this if the first they have ever heard of it. Now I know better.

Going the salt has certainly not saved any me any money of the last 5 years that I have had the system.

Now going back to chlorine.

rbtempe said...

Not sure if you got my post so I'll tray again.

I experienced an explosion of my sal/chlorinator last Thursday night. This is the second time this has happend in the last 18 months.

Of course the manufacturer won't admit to it. They act as if I'm doing something wrong.

Your are right on Pool Man great information here.

I for one am going back to chlorine.

The salt system has not saved me any money or maintenance headaches over the past 5 years. If fact including the initial purchase of the system and already replacing one chlorinator unit it has cost me money.

Anybody smell a class action lawsuit here?

The Pool Guy said...

RB; I appreciate your candid comments. I bet you have pictures of your blown up chlorinator. If you can e-mail them to me, I'll post them in the blog. You can get my e-mail off my profile. Even if you don't have pics, e-mmail me. I'd like to communicate with you. Perhaps I could put you in touch with some industry folks who could take better care of your problem than what you're experiencing now.