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Re: [APD] Re: Help! (Flowgauge Regulator)
I used to work in the fluid power industry so I suspected as much. The
regulator doesn't state what the maximum outlet pressure is. Do you see any
problem with replacing the flow gauge with a pressure gauge to see what
reading I get with downstream blocked? Others have stated that some of
these units give mixed results. Could this be why - it is a flow control
device and not really a pressure regulator?
----- Original Message -----
From: Douglas Guynn <d_guynn at sbcglobal.net>
To: Aquatic_Plant_Mailing_List <aquatic-plants at actwin_com>
Sent: Saturday, December 27, 2003 9:34 PM
Subject: [APD] Re: Help! (Flowgauge Regulator)
> Rick wrote:
> "Does anyone know what the difference is between this and a standard
> regulator and, more importantly, if it matters? If the recommendation is
> set the pressure to 10 to 20 PSI, how would that equate to CFH?"
> A standard pressure regulator will allow enough fluid (in our case gaseous
> CO2) to pass through to maintain a specific outlet pressure, irrespective
> flow (within the operating parameters of the regulator). In this
> application, you open the downstream needle valve, the regulator will open
> enough to maintain the tubing between the regulator and the needle valve
> the chosen pressure. Some of these are adjustable, some are preset.
> I believe the "regulator" you purchased is actually a flow control device,
> not a pressure control device. It will allow enough fluid (again, CO2) to
> pass through to maintain a specific flow, irrespective of pressure (again,
> within the operating parameters of the regulator). Of course, this depends
> upon whether or not the downstream equipment will accept the set flow
> If not, the pressure will continue to rise to whatever the maximum outlet
> pressure of the "regulator" is.
> You cannot convert psi to cfm, unless the system is stable. For instance;
> the orifice size does not change, and the inlet and outlet pressures do
> change, and the composition of the fluid does not change, and the
> temperature of the system does not change, the flow will remain constant.
> any one of the variables change, it will affect the flow rate. If two of
> variables change, the flow may or may not change, depending which variable
> changes and whether it increases or decreases.
> While pressure and flow are related (flow is, after all volume per unit
> time), to compare them is like comparing oranges to apples. They are both
> fruit (related), but definitely nowhere near the same (interchangeable).
> Douglas Guynn
> d_guynn at sbcglobal.net
> "The power to do things for you is the power to do things to you." -
> Aquatic-Plants mailing list
> Aquatic-Plants at actwin_com
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