Membership Chair/ARP Committee / Professional Member*
Now clearly a 12 TXV on a 22 or 502 system will not work at all. The internal pressures of the valve will never overcome the evap pressure force and the evap will starve for refrigerant flow. Got it.
But with say; 22 and 502 - what would happen? The pressures are pretty close - that is; within the normal operating range of the valve. Once the SSH was set wouldn't the valve just carry on? Maybe hunt a little at times, but pretty much 'work'?
Which leads me to my present confrontation: An R-502 (well; purple power head label anyway <g>) flowing R-404 refrigerant.
Actually; I'm not even positive about That. It may well be a R-404 condensing unit piped to a R-502 evap, and then charged with R-22.
Hmmmmm . . . . how can I determine for certain What refrigerant is in the system? I mean without replacing it. <g>
Anyway, my original question is: will there be any substantial performance or reliability gain from replacing the 502 valve with a 404 valve?
PHM
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When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
Educational Committee/Professional Member*
I'm not sure how your going to tell what juice or juicesOriginally Posted by Poodle Head Mikey
ya I seen that before.Now as for the txv's I have retro all out 502 racks with hp80 and did not replace the txv's or power heads. And when I do I use a kt43 sz or sc. Hope this helps some.
I love the smell of phosgene first thing in the morning:
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Membership Chair/ARP Committee / Professional Member*
Because really; the simplest thing For Me to do would be to leave the R-502 TXV, pull the existing refrigerant, and charge the system with R-502.
Because I have at least 50 lbs here with no likely home for it. <g>
PHM
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When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
SDC/Educational/Membership Committee*
The original R502 TEV will work just fine with R404A, both with repect to valve capacity and the thermostatic element's charge.
The current Sporlan "S" charged element is rated for R404A, R507, R402A and R502.
Membership Chair/ARP Committee / Professional Member*
Now if I can just get it to keep running - without constantly locking out on oil failure. <g>
BTW: does the use of "txv" bother you? And you would prefer to have everyone use "tev" ?
PHM
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PHM
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When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
Professional Member*
And we are going to start referring to DX coils as DE coils?
SDC/Educational/Membership Committee*
It's only because I consider Sporlan to be the standard bearer when it comes to Thermal Expansion Valves....and they use the term TEV as opposed to TXV (which is used by Alco).
Membership Chair/ARP Committee / Professional Member*
More industrial-strength or something. <g>
PHM
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It's only because I consider Sporlan to be the standard bearer when it comes to Thermal Expansion Valves....and they use the term TEV as opposed to TXV (which is used by Alco).
PHM
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When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
Professional Member
On a side note, I had a whole line up of M5's (17 valves). They came with danfoss valves stamped 404a. The sys was 408a. No problem for sporlan. When I started the sys it flooded back so bad that the discharge was cold. Shut it down and rounded up 17 balanced ports. Installed them with a helper and had it running by 11 o'clock. Found out latter that danfoss valves only work with what is stamped on them.
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I have found out that a r-22 valve does not work well with 408. It barely worked with 502.
Professional Member
Danfoss valves are ultra sensitive and very touchy, even when applied correctly.
Regular Guest
The use of TXV when refering to a thermal expansion valve is industry standard, just as an electronic expansion valve is refered to as an EXV and an automatic expansion valve is a AXV and so on.
Membership Chair/ARP Committee / Professional Member*
A few years ago I ordered two MT R-404 condensing units and six evap coils. We installed and piped and started. Adjust, adjust, adjust - could not get the SSH down.
Finally I climbed up to a coil myself, with a mirror - and found an R-22 TEV. soon after that I found five more R-22 valves.
Oh sorry dude; we will ship you out six R-404 valves right away.
The job is running, I ordered the coils complete: valves, stats, solenoid valves.
Huh; well we will send you the right valves.
What about the time, trouble, labor, and down-time?
Can't help you.
So anyway - my point is that while R-502 valves may work with R-404 - R-22 valves apparently Will Not work well with R-404. <g>
PHM
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PHM
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When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
Professional Member*
Valve capacity is based on the operating conditions (liquid temperature, suction temperature, and the pressure drop across the TEV port....[yes....TEV]). In addition, the size of the valve...port size and maximum stroke. And finally, the thermodynamic properties of the refrigerant.
Due to those differences in thermodynamic properties between refrigerants, a nominal 1 ton R-502 valve is approximately a .98 ton valve when used with R-404A....very similar thermodynamic properties.
The same valve when used with R-22 has an approximate 1-1/2 ton capacity.
In addition, the pressure-temperature characterisics play a role in determining which thermostatic element the valve should use. The pressure-temperature characteristics of R-404A are close enough to R-502 to allow both to use the original R-502 thermostatic element. The Sporlan S charge is exactly the same as the R charge. Different name, same components in the element.
In the medium temperature range there is enough difference between the pressure-temperature characteristics of R-507 and R-502 that the original R-502 element doesn't work very well.
And there is substantial difference between the pressure-temperature characteristics of R-22 and R-502, R-404A and R-507.....so the R-22 element is not a good choice to use with any of these refrigerants.
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