# ADJUSTABLE PRESSURE



## gollum456 (1 Jul 2010)

Does anyone know if the working pressure on this http://cgi.ebay.co.uk/Dual-Gauge-CO2-Re ... 3a4a90806a is adjustable or not? i need it to go above 1.7 bar to run a UP atomiser.

many thanks.


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## arty (1 Jul 2010)

Allmost all any size and any amount co2 bottles come with presure 60 bar approx., my pub refill stations top up for me on 70 bars, also depend from temperature, higher temp.= higher presure.
If 60bar full bottle, then out approx. is 2-3 bars on my single gauge regulator

Heat Your bottle up to 80C and will be good presuure  (Joke)

Best Regards,


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## gollum456 (1 Jul 2010)

don't know if you understood my question or not, but my current regulator has a fixed 'output' pressure (no main dial) of about 1.5 bar which is insufficient for my needs. i need to know if this reg http://cgi.ebay.co.uk/Dual-Gauge-CO2-Re ... 3a4a90806a is adjustable.

thanks for input anyway.


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## mdhardy01 (1 Jul 2010)

I've been asking the same question but about the tmc and d-d regs
Let me know if you get an answer on this reg
Bit cheaper than the ones I'm looking at


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## JAS (2 Jul 2010)

I can't see an obvious adjustment handle on the ebay reg, but it's possible the knurled portion at the back is a handle.

I don't have any experience with the TMC reg, but again, I can't see an obvious adjustment handle. The D-D regs, on the other hand, have easily adjustable output pressure; just turn the huge black handle on the top.


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## arty (2 Jul 2010)

My TMC too fixed presure gauge. From 60 bar gives me approx. 2.5 bar. 70bar = 3 bar
About other make models i don't know. 


Regards,


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## arty (2 Jul 2010)

gollum456 said:
			
		

> don't know if you understood my question or not, but my current regulator has a fixed 'output' pressure (no main dial) of about 1.5 bar which is insufficient for my needs. i need to know if this reg http://cgi.ebay.co.uk/Dual-Gauge-CO2-Re ... 3a4a90806a is adjustable.
> 
> thanks for input anyway.




I Don't know this CH product.

Regards,


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## stevec (2 Jul 2010)

you may want to read this topic before you order from these guys viewtopic.php?f=24&t=10939

must say though my items arived ok from them was a while back though


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## gollum456 (2 Jul 2010)

just to let everyone know, it is not adjustable, even though it does look it may have a knob on the back.


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## gollum456 (2 Jul 2010)

hi, just an update. if i bought one of these http://www.mig-welding.co.uk/shop/co2-regulator.htm could i take the solenoid and needle valve off my cheap chinese 'all-in-one' and add it to this reg. i cant see why not, but someone might have a reason not to do this.

btw, i think the needle valve isn't very good so i might change that as well. i jump from hardly anything to alot with the slightest turn of the dial.

thanks


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## ceg4048 (2 Jul 2010)

Hi,
   Yes, these should all be industrial standard fittings so solenoid and needle valve can be swapped. As you've mentioned though, you really do need a quality needle valve.

Edit: I've just had a closer look at this unit and it shows the second gauge as Litres Per Minute, which is somewhat useless. Perhaps you can get them to substitute a low range output pressure gauge (in the 0-5 BAR range) instead of a flow rate gauge.

Cheers,


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## gollum456 (2 Jul 2010)

do you think its my needle valve thats causing the output pressure gauge to fluctuate? it moves back and forth about.1 to .2 of a bar and the bubble flow rate peaks and troughs (unsteady). though something tells me however unsteady the bubble rate the needle valve shouldn't be affecting the gauge itself?

thanks, scott


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## gollum456 (2 Jul 2010)

i am also thinking about buying this http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0547761217. when asked, the seller says output pressure is adjustable, though i'm not convinced they fully understand what im asking! they have said however that it is set at 2.2 bar. can anyone confirm this?

also if you look at the pictures there is a dial that appears to be in addition to the needle valve. does anyone have any ideas?

thanks!!


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## ceg4048 (2 Jul 2010)

gollum456 said:
			
		

> do you think its my needle valve thats causing the output pressure gauge to fluctuate? it moves back and forth about.1 to .2 of a bar and the bubble flow rate peaks and troughs (unsteady). though something tells me however unsteady the bubble rate the needle valve shouldn't be affecting the gauge itself?


 Yes this could easily be the needle valve. If the valve opening is fluctuating then it could back-pressure the upstream side if there is no check valve (or other form of isolation) in between the guage and the needle valve. The gauge might simply be showing you the back-pressure fluctuations. The design is really not clear so it's difficult to tell. The problem also could be farther downstream. Does this happen when you separate the regulator from the rest of the system such as tubing and reactor?

Cheers,


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## gollum456 (2 Jul 2010)

this is the exact regulator i have http://www.firststopaquatics.co.uk/cgi- ... #a7077_2f2


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## gollum456 (3 Jul 2010)

gollum456 said:
			
		

> i am also thinking about buying this http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0547761217. when asked, the seller says output pressure is adjustable, though i'm not convinced they fully understand what im asking! they have said however that it is set at 2.2 bar. can anyone confirm this?
> 
> also if you look at the pictures there is a dial that appears to be in addition to the needle valve. does anyone have any ideas?
> 
> thanks!!




an answer for this would also be appreciated as i think this may be the same brand as the atomiser i bought. if so, then quality should be ok?


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## ceg4048 (3 Jul 2010)

gollum456 said:
			
		

> gollum456 said:
> 
> 
> 
> ...


Well, just below the image the product description states the following:

Brand "UP", made in Taiwan
Dual gauge pressure indicators
Industrial-grade Precision Needle Valve
Integrated 110/220V Solenoid 
Solenoid Valve is "JBS (Jin Ben Sun Co., Ltd)"
Compatible with various size of CO2 Cylinders (from 12 oz to 20-lb)
The thread is made according to UK, Europe, Japan and Taiwan standard (JIS m22-14), 22mm in diameter.
Please note this m22-14 do not fit cylinder in USA and Canada.
Free Check Valve x 2.
Item come with UK Plug.

So from the combination of image and description we can only assume that the chrome knurled knob is the needle valve. I don't see any other dials, only the two gauges and what appears to be a green logo "UP", which the product description reveals is the name of the brand. It could easily be misconstrued that this "UP" label is some kind of indication of a valve position, but I think not.

All in all, this seems like a fairly bog standard twin gauge regulator with solenoid. I can't see any faults with this. The high pressure gauge look like it has the right scale to measure industrial cylinder pressures and the low pressure output gauge looks like it goes from 0-10 Bars, which is also fine. We can't really say if any of this is the best of quality, but on the surface looks good. I can't see a reason to avoid this particular unit unless someone who has used this brand reports a complaint.

Cheers,


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## gollum456 (3 Jul 2010)

well, i've already bought it now as the supplier assures me that the 'working pressure' is 2.2 bar. i paid a few quid extra as this one is supposedly supplied from the uk and will arrive in 3 business days. also suposed to have no quibble 7 day return. also i stressed to the supplier that if this reg runs below 1.7 bar i will be returning it and expecting refund for postage costs. all of this exchange is recorded in ebay messages. so heres hoping!!


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## mdhardy01 (3 Jul 2010)

let us know how you get on
as i said ive been looking at the tmc and d-d ones and this would save a few quid
did you get it from the same seller as the link above?


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## mdhardy01 (3 Jul 2010)

o from the combination of image and description we can only assume that the chrome knurled knob is the needle valve. I don't see any other dials, only the two gauges and what appears to be a green logo "UP", which the product description reveals is the name of the brand. It could easily be misconstrued that this "UP" label is some kind of indication of a valve position, but I think not.


clive if you look at the other pics there is another small knob that says off and this looks like it sits near the needle valve
could be wrong though


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## mdhardy01 (3 Jul 2010)

no my mistake
that is the needle valve


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## arty (3 Jul 2010)

I preffer German made things. there is quality. All CH, Taiwan e.g. economy on every material, steel not steel but something like that, plastic only looks like plastic. Almost all power supplies is very unstable on 240V.
I had many things from German in my life and all working well and no broken. I had many thigs from CH,Taiwan e.g. and that is only time question. Almost all CH things broke down due poor qulity.


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## gollum456 (7 Jul 2010)

recieved regulator today. connected up and all seems well. i'm now able to control bubble rate very accurately. it's working pressure seems to be a touch over 2 bar. not quite the 2.2 bar that i was told, but more than ample to maintain 3bps against the UP atomiser. the surging problem has now gone away, so i think it probably proves that either the neddle valve was not up to it, or the pressure being below 1.7 was affecting the flow.

will keep you posted.


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## gollum456 (7 Jul 2010)

nope, hold fire. went out for a few hours and when i came home it had dropped all the way to 1.5 bar. redid all the connections and it held for a while at 2 bar, however at about an hour later and it has slwly dropped to 1.8 bar. dont know why it is doing this.

i was hoping someone might have an idea as to why this is happening????

i have done the soapy water on all the joints test, no luck.


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## ceg4048 (7 Jul 2010)

Is the cylinder valve fully open? Is the cylinder itself fully charged? Open the needle valve fully and then slowly close it in case there are any trapped debris.

Cheers,


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## gollum456 (7 Jul 2010)

yeah did that. when i opened the needle valve fully it jumped back up and stayed there. had to come to work then so unable to monitor it after turning back to 3bps. will check in the morning.


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## gollum456 (10 Jul 2010)

well, some good news. i returned the faulty regulator and had a full refund. i highly recommed the site, which is firststopaquatics.co.uk. the money was back in my account the day after i sent the reg back.

the reg i got now seems to be alright apart from the first few mornings at switch on, only one or two bubbles would come through. however, a good blast with the needle valve wide open then back to 3bps and it will stay like that for the rest of the day. also i've noticed that when the solenoid is closed the pressure will be about 3 bar, yet when its on and letting gas through it will be about 2 bar or even 1.8 bar????


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## ceg4048 (10 Jul 2010)

When the solenoid closes the needle valve is still open so some gas leaks though across the valve to the downstream side. The low pressure gauge reads this trapped static pressure. When the solenoid is open the gas is in motion. Gasses in motion have a drop in pressure so this is why the gauge shows a lower value.

Below is a schematic of a typical Flow Control Needle Valve. This is a different configuration than ours, but it shows the innards the best. Every thing else is just a variation on the same theme. This valve is made by a company called Swagelok. In this image the gas flows from left to right. So the full cylinder pressure of about 200 Bar is on the far left side and that's where the high pressure gauge samples it's pressure from. See the line drawn from where it says Tapered Stem Tip? That's where the high pressure gas gets a drop in pressure as it travels up the very narrow corridor up the stem and dribbles out into the chamber. The gas then finds it's way into that little chamber and then flows out on the right.  Turning the black knob (in our case it's a knurled knob) counterclockwise raise the stem tip allowing more flow and higher pressure up and into the chamber. You can see that this is just a screw which raises or lowers the stem (needle.)

The solenoid is independent of the stem position and would be mounted somewhere on the right hand side. It's either fully open, to allow flow, or fully closed. The working pressure gauge will sample it's pressure somewhere between the right side exit chamber and the solenoid. That's why when the solenoid closes you continue to get some spillage across the stem until the pressures equalize in the chambers and narrow corridor. Whatever pressure value that is when it equalizes is what will be displayed on the working pressure gauge.






Cheers,


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