29 January, 2014

Ever Play With a Blivet?

A while back, I noticed the water pressure from our well had begun to fluctuate every few seconds. A sure sign that something was wrong with the system was what came to mind immediately. Turns out, I was right. The pressure tank was supposed to even out those fluctuations, helping ensure that the well pump, located fifty-five feet down the well, didn't shorten its life and  burn out from overwork.

I knew from the experience of having replaced the tank for our reverse osmosis system, that replacing a tank is a fairly pricey endeavor down here in Belize. I also had a pretty good idea that getting a bladder down here was next to impossible - or so I thought.

I went up to Lano's new warehouse/store up on the Northern Highway in Ranchito, just a mile or so from our house, to price what a new 35-gallon tank was going to cost. After climbing the language barrier with a couple of the new staff (some of Mr. Lan's relatives, who are new to Belize), I managed to talk to Mr. Lan.

He popped up from behind the bicycle counter at his new store, to greet me. His store is a huge affair, as far as Belize stores go. Not only is it a hardware store, but they sell a complete line of motor scooters and cycles, bicycles and parts. There's a Car wash (being set up), auto tire changing station, and a huge showroom upstairs like at the downtown store, but larger.

Anyway, I described to Mr. Lan what I was looking for and asked, on the off-chance, if he had a replacement bladder for the tank. To my utter amazement, he did. Only because he had just replaced the bladder in his pressure tank. In fact, he took me up to the third floor of his new building, where his new home will be, to show me the tank and his jet pump setup - which is what I want to go to after my submersible pump finally dies. A jet pump sits on the surface, in this case, on the top of his tank, not 55- or 60-feet down the well. An arrangement much more suitable for repairs. But, that's another story for another time.

On with the current story. I purchased the bladder, as you can see below. The bladder is made of vinyl, although it feels just like the latex surgical rubber tubing used in slingshots and I suppose, in some surgical applications as well. Anyway, it's quite thick, probably on the order of 1/8" with the lip of the bladder being close to 1/4" thick.
New Water Pressure Tank Bladder
The bladder is not cheap eather. On the order of $335.00 BZD. Of course, if I had the luxury of shopping leisurely on-line, I could have possibly found one for less. Yesterday evening I did just that. But, to my surprise, i couldn't find any bladders for sale. Granted, I didn't look overly long, but I figured I would have no problem finding them in the first place. So, maybe purchasing the one I did was the right thing. It was from a timeliness perspective. Possibly from a cost perspective as well, once you figure in shipping, 12.5% GST, and duty, which can vary depending on various factors.
In my search on-line, I had no trouble finding tanks and bladders and the cost for those items stateside was around $200 - $250 US. So, if you double that to BZD and add in the costs above, it's close to being a wash. Since I already had a good tank, I didn't even consider that option.

Here's the tank that needs the bladder changed. It sits in my well house which is located right next to the front gate of our place. The tank is known by several names - “pre-charged” tanks, “bladder” tanks, “captive air” tanks, etc. After working on it to remove the old bladder and replacing it with the new one, I have a couple other names for the thing. I'll leave those to your imagination.
Water Pressure Tank at Start
Here's a brief description on how one of these things work. By the by, it's called, among other things, a 'pre-charged' bladder tank. As such, it has a bladder inside that is surrounded by pressurized air. The well pump pushes water under pressure into the bladder. When a faucet, shower, etc. is opened, the air pressure inside the tank squeezes the bladder forcing the water out. That's how it keeps the pump from working overtime. Trust me, it's really magic, but I won't go into that here.

Incidentally, I also found out that you shouldn't use the same type of bladder tank for reverse osmosis (RO) systems as for your regular water supply pressure tank. RO tanks have bladders made of butyl rubber, much different than the vinyl we're going to use here. RO water is so pure that it wants to pull contaminants into it. If stored in the vinyl bladder of a pre-charged tank, the “elastomers” in the bladder will be pulled out of the bladder into the water leaving the bladder very brittle. What it pulls into the water can also be considered to be toxic.

Back to the story. Since this isn't the average run-of-the-mill project that one does everyday, I asked David if he'd like to come over and observe and maybe help. It's a good thing that he did, too. I was seriously deluded by some of the videos I watched on YouTube about changing your own tank bladders as to just how challenging this project was. It is NOT a one man project. At least the way that we did it.

The first thing we had to do was get the tank out where we could work on it. As I suspected, the tank was definitely "water-logged" as they say. That is, the whole tank was filled with water. We initially shut off current to the pump and then opened up a near-by hose faucet to drain off any water pressure in the system.
Draining Waterlogged Tank
Next, we disconnected the tank from the system by opening the union (You can see that above) and let the tank drain. This took about half an hour. It's a 35-gallon tank, so it was necessary to drain off at least some of the water before we moved it very far. Fresh water weighs about  8.3 pounds per gallon or 290.5 pounds for the whole 35 gallons. It felt that heavy too.
David Moving Heavy Tank
After we drained probably a third of the water, we managed to get it onto the hand cart and manhandle it outside to finish draining.
Waiting for Tank to Finish Draining
Of course we did all this under the adequate supervision of Nelson, our male kitty who is convinced that he's as much a dog as the three girl dogs who hang around here.
Nelson Supervising Draining
After the tank completed draining, we then were able to flip it upside down to begin removing the 1/2" bolts (8), cover plate, and plastic stand, that supports the tank in it's upright stance.
Bottoms Up
This turned out to be a bit harder to do than we anticipated. Yes the tank was waterlogged, but I think differently than normal. The bladder was filled with water and it had stretched to fill the whole inside of the tank. This blocked the air valve, essentially creating a vacum around the bladder that just sucked the bladder against the tank. David managed to force a long thin screwdriver under the plate and nudged the lip of the bladder enough to allow air in to free the bladder from the tank sides. Without his doing that, we would not have been able to remove the cover plate.

Perhaps that scenario is where the advice on a couple of the videos I watched came into play. They said, for a water-logged tank, the only way to free things up was to poke a hole into the side of the tank. I suppose that would have done it, but then, I'm pretty sure that would have rendered the tank useless. I kind of wanted to reuse the existing tank so we didn't consider that as a viable method.

After we got the cover off, we were surprised to find this length of pipe connected to the underside of the cover. The blue end cap was loose and rolling around inside the bladder. I hadn't seen this in any of the videos I watched. I'm not sure what it does other than maybe it keeps the bladder from collapsing entirely.
Underside of Tank Cover
Then the task really began. We had to get the old bladder out of the tank. Hah! This is where the term 'blivet' comes in. You've got approximately a 4" hole to get this bladder through. Believe me, it took both of us to get it out. We even had to use Vice-Grip pliers and Channel-Loc pliers to gain enough of a grip on the vinyl to pull it out. The bladder was very slimy and very, very slick.
Dave Attempting Removal of Old Bladder
Here's the hole we had to work through - literally. The only way to get that damned bladder out is through there. We thought about cutting the bladder up. It might have worked, but I'm not sure the process would have been any easier (see NOTE below).
Tank Opening
Suffice to say, we ultimately were successful at removing the bladder. Here's the bugger after we threw it on the ground. I felt like stomping it. Can you sense I don't like it?
Old Bladder Finally Out
After we got the old bladder out, David had a great suggestion. There were a few paint blisters on the top of the tank. He suggested sanding and painting those areas to help preserve the tank. I thought it was a great idea too and trotted off to my workshop to get some sandpaper and Rustoleum spray paint. That's the brown you see on the top of the tank below.The color is actually a brown primer, but it was all I had at the time, and besides, it's not like the tank is in our living room.

Dave Filling Tank With Air
It wasn't till near the end of filling the tank with air that I realized that maybe filling it with compressed air while inside a relatively small closed compartment might not be the brightest thing to do. Note to self - Next time use the compressor and fill the tank with air while both you and the tank are outside.

You should have seen both David and me jump the first time the compressor kicked in while it sat inside the compartment. I thought we were goners for sure. After fixing the leak, we did at least move the compressor outside to protect what's left of my hearing.
Tank Pressurized and Watered
[NOTE: The day after all this transpired, I happened to stop in at Lano's new store on another repair and maintenance issue entirely and talked to Mr. Lan. I told him what a hard time we had getting the bladder out. He laughed and said he forgot to tell me he simply cut up the old bladder and fished it out easily, and that he had put a little bit of oil around the rim of the hole. "Oh, make it much easy to get out," he said. Well, at least I now know for next time, and you do too].

 It wasn't long after all this that we had the tank filled with both air and water and functioning the way that it should. No more sense of rapid fluctuations or anything like that. I cleaned up the area, putting the gas cans back in the pump house, all the tools back in the workshop and joined David and Elizabeth, and Dianna on the porch for a nice cold one - richly deserved, I might add.

As for the other matter. It's a leak on the outfall side of my main swimming pool pump. I just can't seem to get the damned thing to quit losing water. Even after twelve or more wraps of Teflon tape, it still leaked. Mr. Lan asked why I didn't use galvanized pipe? He said he is using galvanized pipe on his water jet pump because of the potential for heat and vibration to easily warp the PVC fittings.

What I didn't know is that Lano's now carries a fairly wide assortment of galvanized pipe and fittings, and even has a man on his staff who can cut it and can cut threads. So this next week I'm hauling the length of pipe up to Lano's so he can have his man gin up some pipe and fittings that will be heat and vibration-proof and should solve my leak problem at the main pump.

There might even be a posting about all of that. Stay tuned for developments.

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