Thoughts on Plastic HLT?

[a10t2]

Getting close to putting some money down on equipment and I'm trying to save where I can without cutting too many corners. Does anyone have experience with using a plastic water holding tank for an HLT, specifically an electric HLT? I think I'd have to work out a solution for insulating it effectively, but otherwise it seems ideal. Thoughts?

[Jim Lieb]

I would worry about leaching plastic out of the tank at 190F, giving you off flavors and eventually weakening the tank.
Jim Lieb

[a10t2]

That was my first thought, but it looks like food-grade PET is rated to 100-120°C depending on the manufacturer.

[BrewinLou]

Temp and pressure, not just temp. Can the tank hold the pressure expressed in terms of weight of the water at the temp you would keep it at? As you raise the temp of most materials the strength of said material will go down.

[DaveK]

I looked into this and talked to a plastic tank manufacturer, here's what they told me:

"polyethylene which is rate to handle up to 120 operating and 140 spike. If you are looking to operate at 160 deg. constant you will need to get a polypropylene tank"

For a 500 gallon polypropylene tank I was quoted $2600, almost 10x the cost of polyethylene. I ended up buying an insulated stainless tank.

Dave

[a10t2]

My mistake, I meant PP, not PET... Just using google, I'm finding 450-550 gal PP "1.9 SG" chemical holding tanks in the $1000-1500 range. Less than 1/4 the quotes I've gotten on stainless.