[Homerepairguy]

Support???

Yes, in my personal view, the horizontal method of supporting an expansion tank is good, provided that the attachment of the strap to the wall is solid. Even if the bladder fails and the tank gets full of water, the tank is supported by the strap without putting any stress on the copper pipes, fittings and solder joints. All of the copper is free to move (contract as cold water refills the water heater and expand as water is heated to the max temperature set by the user).

I've read that installing expansion tanks in the horizontal position can wet only the lower portion of the bladder and with uneven wetness of the bladder cause premature failure of the bladder. But I don't think that theory is cause for concern because of how the air bladder in the tank works.

When the tank is pre-charged before installation, the internal air bladder is pressed entirely up against the insides of the tank right up to the water input hole. IOW, the bladder is like an internal coating on the tank. When water enters the tank, it appears to me that the water will be wetting almost all of the bladder with just a very small air pocket if any.

The disadvantage of a horizontal installation is that the tank cannot be drained completely for removal if the internal bladder ruptures and the tank gets full of water.

(Oh, I just realized after typing the above that maybe your posting that picture was a tongue in cheek post for inadequate attachment of the strap to the wall. )

Thanks,
HRG

 

[Homerepairguy]

repairguy:

was this how you used a shelf to support yours on the horizontal installatin?

No, my installation looks like this:

Support for the horizonal shelf is by the diagonal cut sides that extend upward. There's a 3/4" vertical back piece that the sides attach to forming sort of a diagonally cut box. The 3/4" vertical back is screwed to the wall. There's a 6.5" hole in the bottom shelf that goes up 1/4" and then tapers to 9" on the top side of that shelf. This allows the convex bottom of the tank to sit on the tapered portion and allows the hex nut at the water connection to be below the bottom of the shelf. This allows complete access of the hex nut with a wrench in every direction up to the wall. Here's some detail of the shelf:

[FONT=Lucida Console] 
   ---- 3/4" vertical back piece to attach to wall.
  /
 --
|  |\
|  | \
|  |  \
|  |   \
|  |    \
|  |     \
|  |      \
|  |       \
|  |        \
|  |         \
|  |          \
|  |           \
|  |            \
|  |             \
|  |              \
|  |               \
|  | |<----9"----->|\
|  |--             --
|  |  \           /  |
|  |   |         |   | -- hole goes up 1/4" and then 
 --------------------  -- tapers to 9" at the top.
       |<--6.5"->|
|<-------12"-------->|
[/FONT]

The picture is not to scale and the angle of the diagonal is not as steep as shown. The bottom shelf is 3/4" plywood. The vertical piece that attaches to the wall is 3/4" plywood and is 11.5" high. Everything was glued and held together using nails.

Allan's method of mounting the tank on a brass tee on the cold water nipple to the heater is much simpler. However, even if I knew that when I installed our expansion tank it wouldn't have worked for us though. The company who installed our solar water heating system installed an anti-scald valve that connects the cold to the hot directly above the water heater using all copper pipes. I had to tee off above that assembly to access the cold water input to the heater.

Hope this helps,
HRG

 

[hammerlane]

No, my installation looks like this:

Hope this helps,
HRG

No your installation looks like a bunch of lines and dots.

 

[Alan]

Some of us have been watching you.

:shifty:

 

[Homerepairguy]

No your installation looks like a bunch of lines and dots.

Sorry about that. While the picture looks fine on my desktop PC, I just looked at them using my laptop and now see that this forum does not display them the same way on different computers. Here's a photoshop picture with dimensions:

(Edited side panels in picture to match actual shelf that I built.)

Hope "this one" helps,
HRG

 

[hammerlane]

If your expansion tank is hung vertically, you could always use the 3/4 copper hangers secured to the underside of the subfloor to help support the copper pipe in the area of the expansion tank.

 

[Homerepairguy]

If your expansion tank is hung vertically, you could always use the 3/4 copper hangers secured to the underside of the subfloor to help support the copper pipe in the area of the expansion tank.

Looks good. Thanks,
HRG

 

[AllanJ]

For the horizontally mounted tank and strap wrapped around it, the higher above the tank the strap is fastened to the wall, the more secure the fastening is.

 

[M3 Pete]

We put one of these in along a horizontal section of cold water pipe that branched off from the water heater feed and supplied a section of the house. It was the smaller 2.1 gallon DET-5 model, configured vertically with the outlet facing down.

Given that the most the tank could weigh when full is about 20 pounds (23.8 pounds, to be precise), we figured that strapping the tank to the wall, and supporting the horizontal 3/4 copper pipe along that same wall should be sufficient. The line going to the expansion tank does angle out from the horizontal pipe, so there is some torque on the horizontal pipe, but that is minimized by strapping the tank to the wall.

 

[Homerepairguy]

We put one of these in along a horizontal section of cold water pipe that branched off from the water heater feed and supplied a section of the house. It was the smaller 2.1 gallon DET-5 model, configured vertically with the outlet facing down.

Given that the most the tank could weigh when full is about 20 pounds (23.8 pounds, to be precise), we figured that strapping the tank to the wall, and supporting the horizontal 3/4 copper pipe along that same wall should be sufficient. The line going to the expansion tank does angle out from the horizontal pipe, so there is some torque on the horizontal pipe, but that is minimized by strapping the tank to the wall.

Periodic inspections of the tightness of the strap might be a good thing. I don't have a clue if this is a valid concern but am wondering if the daily expansion and contraction of the tank might loosen the strap just enough to allow the tank to slide down a bit at a time every time the tank is cooled.

HRG

 

[M3 Pete]

Periodic inspections of the tightness of the strap might be a good thing. I don't have a clue if this is a valid concern but am wondering if the daily expansion and contraction of the tank might loosen the strap just enough to allow the tank to slide down a bit at a time every time the tank is cooled.

HRG

The tank is about 3 feet away from the water heater, and only carries cold, so thermal expansion is not going to be huge, although the tank is in the attic where it can get pretty hot. I have insulation around the tank and pipes just in case it gets to freezing in the attic, but that's unlikely given our climate, and the fact that the garage is insulated and will keep leaking a little heat up into the attic on nights when it gets below freezing outside. Plus the proximity to the water heater should keep water in the tank from freezing.

The tank is being supported by the piping, and the piping is supported by pipe supports. The strap is merely keeping the tank tight to the wall, and keeping it from rotating away.

But now that I'm thinking about it, I could throw in a couple copper straps just on either side of the tee, just to make sure. 24 pounds is not going to stress the joints too much, as long as the pipe is well supported.

My plumber did screw up and put a shutoff before the expansion tank. But since that line supplies the kitchen, I'm sure we'll notice that the water is off. And the house never had an expansion tank for the last 28 years, so I'm pretty sure we'll get by on a temporary basis.

 

[Homerepairguy]

The tank is being supported by the piping, and the piping is supported by pipe supports. The strap is merely keeping the tank tight to the wall, and keeping it from rotating away.

But now that I'm thinking about it, I could throw in a couple copper straps just on either side of the tee, just to make sure. 24 pounds is not going to stress the joints too much, as long as the pipe is well supported.

Piece of mind would be well worth the effort :thumbsup:.

HRG

 

[ldbrown]

New Product

Here is a new solution that I understand will be available by the end of May '012. Uses quick-release bands to attach the tank.

 

[Homerepairguy]

Here is a new solution that I understand will be available by the end of May '012. Uses quick-release bands to attach the tank.

Looks good. Wonder if they will be making them for 4.4 - 5 gallon tanks?

HRG

 

[AllanJ]

Note that the amount of water that enters the expansion tank under normal operation is the same no matter where in the system the expansion tank is located.

The amount of water that enters the expansion tank depends on the size of the water heater tank and the before and after temperatures of the water inside being heated.

 

[Jeeps]

This tank was installed by a mechanical contractor at work 6 years ago and I think it is a bit whoppyjawed on one end....

I welded up my own bracket for it before the tank broke off the 1-1/2 " cold line and flooded the mechanical room. ...

 

[Alan]

This tank was installed by a mechanical contractor at work 6 years ago and I think it is a bit whoppyjawed on one end....

I welded up my own bracket for it before the tank broke off the 1-1/2 " cold line and flooded the mechanical room. ...

That is pathetic.

 

[M3 Pete]

Note that the amount of water that enters the expansion tank under normal operation is the same no matter where in the system the expansion tank is located.
.

True. But I would think you may not want to install one on the hot water side of the water heater, because then you have 1-3 gallons of cold water in connection with your hot water line, and I'd think it would tend to cool off the hot water as it passes by, as the cold water sinks.

 

[Alan]

True. But I would think you may not want to install one on the hot water side of the water heater, because then you have 1-3 gallons of cold water in connection with your hot water line, and I'd think it would tend to cool off the hot water as it passes by, as the cold water sinks.

Besides the fact that manufacturer's installation guide says to never install it on the hot water side.


:huh:

 

[TheEplumber]

Here is a new solution that I understand will be available by the end of May '012. Uses quick-release bands to attach the tank.

I've always been impressed with Holdrites products. They seem to come up with some real ingenious time saving stuff. :thumbsup: