I have been fermenting in plastic conical with threaded fittings for years.
I also have 350 Gal plastic fermenters in the brewery.
Those are fitted with CIP ball for cleaning.
To answer your question. They do work just fine. How do you plan controlling the temperature?
I am in Hawaii. At elevation 2000 ft. MSL ambient air temp fermentation is no problem year round. A shaded building with interior walls in the fermentation room should hold steady in the low 70s F. Maybe a couple of window unit type ACs for hot days. Lucky thing... residential electricty cost 48 cents per kWh on my last home electric bill. Commercial power is even higher. We are going with PV panels ASAP. The payback period for PV is very short here, especially with the tax credits available.
I remember seeing pictures posted here a few months ago of someone's brewery. I think they had something to do with the construction of a walk in cooler. In those pictures I saw ar least one of these MDPE cylindroconical type of fermenters. I was hoping that someone who uses them would respond.
Are there any flavor problems with the first batch(es)? Do they need curing prior to production? The spec sheet lists MDPE and HDPE as having "suspected" stress cracking possible with long term exposure to ethanol containing liquids. Have you seen any of that?
Thank you for responding. Your input is greatly appreciated!
Most commercial brewers looked down when you mention plastic fermenters (Most of the time these brewers did not foot the bill for SS fermenters). There is no used equipment market out there right now. So compare 10 BBL fully outfitted plastic fermenter $1000 vs. nice 10 BBL SS fermenter $10,000 http://breweryparts.com/index.php/fermenters-and-tanks/beer-fermenter/fermenter-1.html
(I know GW Kent is top of the price range but other importers are not much cheaper).
Get white plastic fermenter. Yellow/Green are not for FDA compliant. Plastic tanks can not be pressurized because of lid design. You would wash CIP them before first/every use. No off flavours at all. What size are you looking at?
Finally one day I would LOVE to have SS fermenter.