# Safe Maximum Temperature for an unpressurized EPDM-lined Storage Tank?



## cguida (Dec 7, 2008)

What is the safe maximum temperature for an EPDM-lined storage tank?

Is there a margin of error?

How will you know you have exceeded the maximum safe temperature?  How much is 'Too Hot,' and what happens if it gets too hot?

Has this ever happened?  Any first-hand accounts?

Thanks

Smee


----------



## WoodNotOil (Dec 7, 2008)

Hey smee

I try to not let it get more than in the low 170s as I have seen the high limit around 175*.  It most likely can take temps for short periods higher than that, I have heard people say they have done it without problems.  I have not heard of any liner failures yet and some people have been using the SSTS tanks for a number of years.  Anyone out there pushing the 20 year life of one?  Goodluck!


----------



## radarblip (Dec 7, 2008)

Smee,
My unpressurised tank with EPDM liner regularly sees temperatures ranging from 175 to 183 degrees, and I going on my third year with my tank.  If you google "EPDM temperature properties" some websites give you a maximum temperature of 225 degrees F., with an intermittent rating of 275 degrees F.  My experience has been that atmospheric tanks never get hotter than 185 degrees F. (At least my never has.)
Bob


----------



## in hot water (Dec 7, 2008)

What grade do you have?  This table is from one of the EPDM roofing manufacturers.  Higher grades show 300F.

There are a bunch of old Chiles Power Systems in my area.  I've worked on 3 that are 18 years old without any leaks.  Plywood tank with EPDM liners.  Many of the seals and gaskets in hydronic components are EPDM.  usually they carry a 225F temperature rating.

 hr


----------



## sweetheat (Dec 7, 2008)

My 806 SSTS EPDM storage tank has a sticker saying DO NOT EXCEED 180 DEGREES Fahrenheit. I have had temps to 169 degrees Fahrenheit top readout. If I'm concerned the temp will increase I turn the thermostat up on my in-floor radiant heat zone. sweetheat


----------



## WoodNotOil (Dec 7, 2008)

Most of us are using the firestone EPDM pond liners and I think they have the same limit as the SSTS liners (probably the same material).  I would not trust commercial ratings that don't apply to the firestone liner as they are a different product all together.


----------



## Dave T (Dec 7, 2008)

Basically EPDM with any different name on it (Firestone,Genflex,mule hide,manville) all from Carlisle, and yes there are fire rated EPDMs that suggest a higher heat rating this is what you boilers are after..Dave


----------



## heaterman (Dec 8, 2008)

Talked with the guy (I forget his name) at STSS regarding this last summer. He recommended 170* for continuous use. Max of 180*. Above that he said the life expectancy drops off rapidly. I didn;t inquire as to what exactly "rapidly" meant. At the time i was researching for a customer and thought I should get the info right from the horses mouth so to speak.


----------



## Fred61 (Dec 8, 2008)

I'm seeing online vendors offering both 45 mil and 60 mil EPDM pond liners. Is thicker better?


----------

