View Full Version : Glycol supply pressure bypass

09-08-2010, 06:10 PM
What types of supply line overpressure protection are you guys using in your setups? We need some sort of basic protection in case someone...careless employee, brewery owner, etc... shuts off every tank in the loop and there's nowhere for the supply pressure to go, except for a weak spot in our piping where it explodes. I have heard about putting pressure bypass valves at the end of the line between supply and return, but I don't know what type of valve is best. Clearly it needs to be adjustable. Also, I don't know why you would put it at the END of the line, especially since the end will constantly be moving as tanks are added...seems to make more sense to put it right out of the chiller unit since that will be the highest pressure in the line and that piping will never change.

09-08-2010, 09:23 PM
Hi Judd,

Here is an earlier post with an option from Mcmaster Carr:


We suggest placing the bypass at the end of the supply loop, assuring you will always have positive pressure to the inlet of each solenoid valve. We've had cases (with a pressure bypass at the chiller system) in which a solenoid valve at the end of the loop opened, but this didn't decrease the pressure enough at the bypass valve for the valve to close. This resulted in low flow/low heat exchange at the vessel.

Good Luck,


09-08-2010, 09:24 PM

09-09-2010, 07:23 AM
Gotcha. I guess you would just have to move that valve down the line every time you add a tank. Those valves from mcmaster are insanely expensive for 1.5" pipe, which is what my header is gonna be. Any cheaper options?

09-09-2010, 11:05 AM
It doesn't necessarily need to be at the end, I think even having 2/3 of the way down the header is better than at chiller system.

You don't need a valve to match your header size- I think a 3/4" would be adequate- this will essentially bypass the same flow volume as a single fermenter.

Good Luck,

07-10-2013, 09:31 AM

I would like to install one of these in our system. I'm looking to install a 3/4" valve between our 3" supply and return line at the end of the loop. These valvs all have the in port at the bottom and the out at the side. Would it matter if I "T" up from the supply line and then go out the side port and down to the return line? Our supply and return lines are parallel.



08-12-2013, 04:44 AM
I'm about to rebuild my glycol circulation system. I have two bypasses in it & it still gets well over the 15psi that my old tanks are rated for when they all take a break. Maybe my pump is too high pressure - I have to restrict the outflow by hand at times.
I'm considering building an insulated "water tower" bypass using foot pounds to deliver the pressure & a spillway to bypass.
I need a good reserve tank for make-up because half my tank jackets leak glycol too.
Any comments?