Strange regulator behaviour...or not?

[Fingerlickin_B]

Hi people,

My CO2 regulator is a Harris 601.

Until recently, except for extended periods of non-use, I've always left the CO2 cylinder tap open all the time.

So...I'm not sure if this recent experience is normal, or a sign that my regulator needs a service.

Recently I've taken to turning the cylinder tap off overnight & regulator tap in set position.

Sometimes when I turn the cylinder on the following day the outlet gauge sits at the set pressure (or rises to set pressure if a few beers were poured without remembering to open the cylinder tap).

However...sometimes the outlet pressure keeps rising past the previous set pressure by anywhere up to 4-5psi more.

So, is this indicative of a sick regulator in need of repair, or somehow related to me leaving the cylinder tap off for some time?

PZ.

 

[mckenry]

I reckon the regs I've owned are seriously not very accurate. I've posted a bit on regs lately. Harris was the other one I've owned (couldn't remember before).
When the needle 'overshoots' does the beer pour faster? That would indicate a service required as the feed really is not being regulated.
If it pours the same, then the needle is probably sticking and it really was your set pressure.
This kind of thing happens a bit to me. I sometimes do a leak test overnight and the pressure appears to have increased. That's ok by me, no leaks. If this causing over carb issues, you really need a service or a new reg. Geez, these things are getting so cheap, theyre almost throw away items these days.
The other thing that causes feed change is temperature. Is your bottle and reg subject to heat variation?
I don't really care if they hunt around a bit, but have no impact on the beer.
The other thing I find is that when the keg or the CO2 is nearly empty, I cant rely on the gauges. The pressure seems to rise quickly, just before the bottle empties.

 

[DJ_L3ThAL]

It could also be as simple as the user (yes, you!) opening the cylinder valve too quickly, slamming full cylinder pressure onto the regulator inlet forcing the diaphragm to open the seat slightly, upping the pressure somewhat. If you pop your regulator ring pull relief (or given Harris don't have one, pop a keg relief on top for a second or two), does the regulator then find the original set pressure? If so my original theory is likely what is occurring.

Cylinder valves should be cracked slightly to bleed gas into the regulator inlet in a controlled manner, then once in steady state, open the cylinder valve fully. Leaving the cylinder valve semi-cracked will cause leaks from the handle stem as you are only letting partial cylinder pressure into the outlet orifice and putting a proportion of it into the valve stem seal which is not designed to take cylinder pressure across it fully (as the gas flow will follow path of least resistance which is the outlet orifice if the valve is fully open).

Hope that helps!

 

[DJ_L3ThAL]

Also Mckenry is correct, homebrew regulators are bargain basement cylinder regulators from what I've observed. Stuff I see at work is typically $500 per regulator and the spring adjustment control is both smooth and far more accurate than what I've seen so far, minimal creep from full flow to static state of 10-25kPa. I recently returned my faulty keg king MKII reg and have purchased a micromatic as they appear to be as good if not better quality than Harris with additional feature of ring pull PRV which is handy for operating purposes.

 

[DJ_L3ThAL]

The other thing I find is that when the keg or the CO2 is nearly empty, I cant rely on the gauges. The pressure seems to rise quickly, just before the bottle empties.

This is because the cylinder is filled to a pressure of 5700kPa typically, it will remain at this pressure as you consume gas, because the CO2 will find equilibrium by boiling off some liquid to replace the gas you consumed. Once this liquid is consumed completely thee is 5700kPa of gas left which drops very quickly as you don't have liquid boiling off (and expanding at a ratio of approx 1:450 liquid:gas).

So really the high pressure gauge just tells you you have liquid left in the cylinder, until the day you don't anymore.

Only way to monitor contents and usage is to weight the bottle when you get it full and then weigh it along the way to see the weight difference. E.g. A 2.6kg bottle will be around 9.5-10kg full.

 

[stux]

I've found Micromatic to be a more reliable regulator than tesuco. My tesuco started creeping, which is apparently a common issue.

 

[Fingerlickin_B]

Temperature variation could definitely be an issue!

I just realised whilst daydreaming of beer today that this has only started happening since I changed to a slightly smaller fridge & had to move the cylinder outside of it.

Will record cylinder pressure when turning off at night & then check for variance at beer o'clock the next day before turning it back on.

Given that it only happens sometimes, this might be worth investigating first.

I probably didn't think of this before because I used to use a giant 31kg cylinder mounted outside a fridge...but...it was down to about 3kg when I got it, so temperature may not have affected it's static pressure nearly as much as a full 6.8kg cylinder...doh!

PZ.

 

[Spiesy]

I've got both Harris and Micromatic - I've found them both to be equally reliable.

I like the PRV in the Micromatic.

I like the easy to turn rotary of the Harris.

 

[Fingerlickin_B]

I've monitored the cylinder pressure at different times/ambient temperatures & that is exactly what's causing the regulator to act as described.

All good I guess

PZ.