In Line Flow Valves/compensators

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brasserie de cancrelat
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Most who ordered them as part of the bulk buy. should have their compensator/in line flow valves by now(just a few are yet to pick theirs up).

I have yet to install mine and interested to know how people have gone with them - whther they have used the JG stem/barb to attach the line and if not what ID size line.

Also be interested about their performance.

Have yet to install mine.

any photos of an installation would be good to see

Connected mine up today, I ended up going the john guest barb fittings ($3ea?) apparently the 6.35id line that fits them does not like kinking too much :( so with the barbs I use the 5mm id line. Working well so far but I think they have some tweaking to do yet. :p I shall give it a good run tonight.

What od size tube is required for these?

I have 7mm od 5mm id and the 7mm od is not enough to even touch the sides of the restrictor.

Am I missing something here? Are you meant to just push the tube into the grey bit and it holds?

Well I grabbed a length of the stuff that does fit it and acording to what is written on the side of it:

COBRAFLEX ID=6.35mm Wall=1.575

So that gives an OD= 9.5mm and it seems to fit fine. You do just push it in and it should bite when you try and pull the liine back out.

This stuff aint that flexible due to the width however so I was happy to get the barbs and use 5mm id line :)

Pouring great :chug:
JasonY said:
Connected mine up today
That's an interesting setup you have there with the taps close together in the door.
Got a closeup outside pic of the door?
BrentonSpear said:
Very good. Now where do I get these barbs in Melbourne?
Suggest you call ANDALE HOTEL SERVICES 55 King St Airport West 3042 (03) 9335 1066. I know this is where Doc got his in Sydney. I intend dropping into Andale in Adelaide.

In a previous post Doc advised "will need the Tube Host Stem 3/8" with 1/4" barb Part number J6HS4 x 2 per flow controller (one for the inlet and one for the outlet)"
Nice setup Jason.

It looks like you used the hose stems there - is that right? can't you just shove the hose into the faucet? that's what I did with my non-roach compensator which is for 5mm line...

I believe that you can also get hose stem adapters which will take a 5mm line on the hose barb with the other end 6mm to stick in the faucet - saves the stuffing around with a different size line
sorry to bump this to the top, but can someone explain what these in line flow valves are used for??? I've tried to google it but I get a whole bunch of garbage.

Given that keggin is iminent, do I need to consider these before I start hacking away ??
Excuse my ignorance - but if u don't ask u don't know!!!!!

Quincy, to get the kegging system to pour correctly you need to have a pressure drop accross your beer line that is a little less than the serving pressure you use (say 100kpa). If you use just 5mm beer line say then you will need about 4 - 5m of beer line to give you the 95kpa drop you need (otherwise the beer shoots out like a rocket and you end up with a beer shower).

The compensators allow you to put a pressure drop in the line that you can adjust as you need so in my case I now have < 1m of beer line instead of the 4.5m on each tap.

I am having some bubbling in the beer line problems but I think that is due to my fridge getting too cold and overcarbonating the beer and not the compensators.
Jason, Thanks. Starting to make sense now. When I purchased my disconnects and lines etc the guy told me 2 metres of beer line would give me the pressure drop required?????? The id is 5mm (I think).
I think I will set up with what I have and see how it goes. Line is reasonably cheap so if I have to but an additional couple of metres - thats OK.
Bit worried about the waste of beer aspect though ! ;)
Thanks Roach, now have my compensators in my hot little hand, well done. Tried connecting them between the beer bottle and the glass but the fittings didnt seem to work. So it looks like I might have to buy some kegs to get them to work properly.
Guest Lurker said:
Tried connecting them between the beer bottle and the glass but the fittings didnt seem to work. .
until then maybe you could put them in a jar of beer on the bar - i am sure the valves will slow the flow :lol: :lol:

4mm ID line has a resistance of about 49 kpa/m. So if your pouring pressure is 100 kpa you will need 1.7m of 4mm ID line. This will give you 15 kpa of pressure at the tap.

5mm ID line has a resistance of about 38 kpa/m. So if your pouring pressure is 100 kpa you will need 2.25m of 5mm ID line. This will give you 15 kpa of pressure at the tap.

6mm ID line has a resistance of about 13 kpa/m. So if your pouring pressure is 100 kpa you will need 6.5m of 6mm ID line. This will give you 15 kpa of pressure at the tap.


Thanks. It seems that my 2 metres should be OK if my pouring pressure is kept @ 100kpa. I understand that it may need a little tweaking etc given that it is not exactly the right length.

All these tips are greatly appreciated.


Good post, valuable technical infomation.

Matches fairly closely my experinces. I use silicone tubing with an ID of 3/16" (about 4.7mm). I've got 2.5m for each ale, and serve between 85-100 kPa. This gives a very nice pour.

For lagers and other highly carbonated beers I've invested in the "Roach Restrictors" to cut down on line length.


How are people finding the Roach Restrictors? Have you been successful in varying the pressure that you pour eg changing from ales to lagers, or have you just set and forget?

I don't have the CO2 bottle permanently connected, so only use the CO2 bottle to top up the kegs once the pressure runs low. So the restrictors are gr8 for adjusting to take into account the drop in head pressure.

Also have used them on a take away setup on a picnic tap with a 3 gall keg - no need to take gas bottle at all if only for 1 session.

There is a limit to how much you can gas the keg up and expect the restrictor to make the adjustment to ensure properly pouring. If too gassed, froth will still come through the restrictor.

A major benefit for me for the restrictors is no long beer lines in the fridge knocking over glassware and getting tangled. Tho the idea of coiling up the beer line and taping it up is a pretty good, as suggested by a AHB'er recently.

I found that I was getting some gassing in the portion of the line after the compensator when the system was idle, so I moved it right up to the gun and it was better. However I eventually took it off because I was getting real thirsty waiting for the glass to fill. Its great advantage is when the visitors filled their glasses, no more having to hose out the floor in front of the fridge next morning.

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