Gas regulator question

[kevputo]

Will a normal CO2 regulator work if it's feed line has already been reduced signficantly from the bottle pressure? Specifically, I need to reduce from 35 down to 18 psi. From briefly researching regulator specs, they seem to have a max inlet pressure rating, but nothing about a minimum input pressure.

Here's my connundrum. I need 2 separate serving pressures inside my kegerator (2 kegs at ~18psi for beer, 1 keg at ~35 psi for soda/seltzer water). My fridge doesn't have enough space to fit my CO2 bottle with a dual body regulator inside. It has a hole sized perfectly to run 1 gas line in from the outside, but I'd have to do a bit of modification to run 2 lines in parallel. I'd rather not do that, if it can be avoided.

So here's what I'm thinking: Split my regulator up to have one at the tank, set to the highest of the 2 pressures (35psi), then split the line inside, with 1 branch feeding into the soda keg, and another as the supply line for the second regulator body. The second regulator would be used to reduce from 35psi to 18, and it's output line would be branched off to feed the 2 beer kegs.

Just curious if this will work, or if I need a special type of regulator for this kind of fine tuning adjustment. Sounds more complicated after typing it out than it did in my head.

The other less attractive option I had thought of was mounting the dual body regulator inside the fridge, and running the CO2 direct from the bottle through the wall of the fridge (using brass pipe, to withstand the unregulated pressure). I don't like this idea since the tank mounting would be inflexible, and it seems like there is a lot that could go wrong with the relatively long & complex run of unregulated CO2 between the bottle & regulator.

Any thoughts, besides getting a bigger fridge?

[Frank]

It can be done, there's no real "minimum" input pressure for a regulator except for the desired output. (You can't have an input of 18 PSI and get 20 PSI out, I am sure you already know this but just want to cover the all bases) There is a popular multiple regulator set up that I plan on using in my storage freezer. To save the hassle of explaining it here's a picture.


(I love having free time)

[kevputo]

That is exactly what I was planning to do, with the line between the first regulator and the first tee passing through the fridge wall. Thanks for the sanity check Frank!

[Frank]

This is a basic idea of my plan. I will have the main reg and CO2 outside my deep freeze and run one line in through a collar. Then I have a 4-way manifold on the inside and each port will run to a different secondary reg. That way I can set it and forget it for 4 different desired carb levels.

Let me know if you need links to parts.

[kevputo]

I have the regulator & tees, just need to pick up some gas line, check valves, flange fittings, and some clamps.

I was planning to shop around at More Beer, Midwest, N Brewer, etc to find the best deal. But if you've got a suggestion for a place with good prices, that could save me some time.