Storage tank questions

[Bad Wolf]

Okay its crunch time; I just bought a 52" x 24' pool (sides only) that I'm going to cut down to make a 7.5' dia tank. I'll be ordering the EPDM liner next and putting 4" of foam insulation on the bottom.
What are people doing about sensors points? Are you installing immersions wells through the sides? I shudder at the thought of cutting a hole in the liner but if that’s the way it’s done. I will need one for the boiler and a couple for the solar panels.
Also how are most people installing the coils? Through the top or through the sides? If I go through the side I would still do it above the water line just to minimize potential leaks.

Does anybody have a source for these parts? TARM wants $20 apiece for ¾” tank penetrations. I’d need 8 ouch!!

Thanks
Greg H
TARM Excel 2000 on order
1100 gal storage tank under construction
4 cords of oak and 2 more to come.

 

[Eric Johnson]

Nofossil uses a piece of 3/4-inch copper pipe that goes through the top of his tank, into which he puts the probes (one at the top and one at the bottom).

I'd go through the top with everything. There's less chance of leakage.

I'd get the EPDM connections from the place you buy the liner. They're not cheap, but not $20 each, I don't think. Maybe you can cobble something up with PVC fittings cheaper.

 

[MrEd]

Not to hijack the thread, but I have a similar question for a propane tank:

Using only top (actually the side near the top), 3/4" holes that are available after plumbing the feeds in and out , what is the best way to monitor the top, and the bottom of the propane tank? Anyone have a link to a website that sells these types of thermometers?

 

[free75degrees]

For my fittings I was planning on making a hole in the epdm that is smaller than the pipe going through, then stretching the epdm around the hole and clamping the epdm to the pipe with a stainless hose clamp. I tried it with some scraps of epdm i had lying around and it worked. I just have to hope that it will hold up over time. Has anybody ever tried this or can anybody think of any reasons why this wouldn't work?

For my temp sensors I cut some 1/4 inch soft copper refrig tube into segment about 2 inches long. I cut one end of each section with harware shears, so it smushed that end closed. I then dripped solder down through the other end so that it made a seal at the inside of the smushed end. I then soldered a ds18s20 sensor to some underground rated rubber wiring and used shrink wrap to cover the connections. Then I stuck the sensor into the copper tube segment and used larger shrink wrap to seal the joint between the copper and the underground wire. Then I used some liquid electrical tape to generously coat and seal the outer shrink wrap and the edges where it meet the copper and underground wire.

The liquid electrical tape is rated to over 200*F and is one of the few sealers that i could find that sticks well to the rubber underground cable. I plan to submerse these directly into the tank water. Only time will tell how they hold up. I submersed one for about a month in room temp water and it still works fine. If they leak it will be no big loss - I'll probably just switch to much longer segments of the 1/4" tube so that I can have nothing but copper submersed (they would enter from the top to avoid uderwater penetration).

 

[Dave T]

Free75degrees,
You mentioned cutting a hole in the EPDM liner and clamping it to the line..THIS WILL WORK and beyond that it will work well,as you said use a stainless clamp.. CUT A ROUND CIRCLE,NO STRAIGHT SLICES OR JAGGED CUTS if you slice straight or jagged the liner will fail due to expansion and contraction splitting the slice further than the clamp..Nice round hole and about 1 to 1 1/2 of EPDM up the pipe..The stainless clamp is all you need,although in the commercial roofing industry caulk is also used to seal any little nooks that water can get trapped in..Good luck
DAVE

 

[free75degrees]

Thanks Dave, I'll definitely go with the hose clamp method. You should too Greg - much cheaper than 20 bucks per hole.

Marc

 

[WoodNotOil]

That is a great tip guys! I will most likely use that method when I get to that stage next week. I plan to run all pipes through the lid of the tank as well.

 

[Dave T]

To get enough stretch around the pipe the hole must be quite small approx 1/8"to a 1/4" at the biggest for a 3/4 pipe then use tape just on the end of the pipe to cushion the end of the pipe through the EPDM with no rips...Look on the bright side if you rip a 1/4"hole open to far,It costs you the 20 dollars you were going to spend in the first place. If you get the pipe through,cheap detail.
DAVE