What happens when capacity of system is exceeded?

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Tim
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Re: What happens when capacity of system is exceeded?

Post by Tim »

tbirdtbird wrote: Mon Aug 30, 2021 8:50 am Tim surely knows of someone that can do custom hose. The experts here are all from hi-temp areas such as AZ and NV, someone will know.
JohnHere has referred ppl to ColdHose in FL but I am sure you do not need to ship that far.

I am gonna guess you would need a TXV rated at 1.5 tons but now that you have made this decision I would think Bohica or Detroit could better advise.
There are a couple of places locally that will do hoses. AAPAK, AZ Auto Air, and Air Compnenets. There are more those are just a few.

Shipping hoses, Cold Hose.
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cyfi66
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Re: What happens when capacity of system is exceeded?

Post by cyfi66 »

Do any of these places do custom AC hard lines?

Biggest issue I see with fitting an H block would be adapting the lines to fit the openings on the valve. I presume I would need to take one from another application and cut off the lines from either side of the H block so they could be adapted/welded to my lines or if there is some other aftermarket option with threaded fittings of some sort. I looked at the TXV's on Cold Hose and they dont provide a tonnage rating. I looked through some on Air Components and they all seem to be for OEM fit situations most of which dont provide a tonnage.

Is there a problem with going with too large of a TXV? If I wanted to steal a TXV from another vehicle whats the best way to figure out which vehicle to pull it from? Could I find another vehicle with similar compressor displacement and use the TXV from that application or are those two things not correlated?

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Re: What happens when capacity of system is exceeded?

Post by tbirdtbird »

Ask Tim here the forum owner and AC supplier about a generic TXV and I am sure that if the BTU rating is not shown that he could find out. Same for those at ColdHose, ask and they could find out, but Tim is closer and knowledgeable, and his prices are right
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Re: What happens when capacity of system is exceeded?

Post by Tim »

tbirdtbird wrote: Tue Aug 31, 2021 9:18 am Ask Tim here the forum owner and AC supplier about a generic TXV and I am sure that if the BTU rating is not shown that he could find out. Same for those at ColdHose, ask and they could find out, but Tim is closer and knowledgeable, and his prices are right
A 2-ton valve has always been my preference, 1.5 will also work.
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cyfi66
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Re: What happens when capacity of system is exceeded?

Post by cyfi66 »

I found a pretty comprehensive product catalog for TXV's here

https://www.uacparts.com/legacy/UACproducts_EX.html

Unfortunately I cant find and 2 ton metric reverse flow O ring internally equalized TXV's which would be great because that would make it a drop in replacement. https://www.uacparts.com/legacy/Search/ ... Dimen.html

Of course I could always go with an SAE valve and just have the fittings cut off and weld some SAE fittings in place https://www.uacparts.com/legacy/Search/ ... Dimen.html

It just seems like going with an H block is going to be a lot more fab work since it would be hard to source the mating flanges for each side. There are a lot more options when it comes to valves though it seems, and they do have threaded ones. https://www.uacparts.com/legacy/Search/ ... Dimen.html

Ill keep searching for a metric 2 ton that I could install onto my metric lines but the above catalog seems to be the most comprehensive I am going to find.
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Re: What happens when capacity of system is exceeded?

Post by DetroitAC »

Why wouldn't the current TXV work? Why do you need to put in an H block?

I don't agree that you NEED a cross charged head or bleed seat. You have a nice big fixed piston compressor, system charged head or cross charged would both work fine, whatever your existing valve head is will work fine. This compressor is incapable of low loads, oil return is not an issue.

H blocks are cheaper and more reliable, more assembly friendly than your externally equalized right angle valve, but it will be a major pain to adapt lines, and for no benefit that I'm aware of. Chime in if there is a benefit I'm overlooking.

Seems like you need a suction line without an EPR, the EPR was assembled into the existing line, so maybe it comes out easy or maybe it'll be destroyed, but that seems ok. Yank that suckered out and you have a perfectly routed suction line with an already built port for the external equalizer.

All that will take some work is rigging up a way to cycle the clutch to keep the evap from freezing up
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Re: What happens when capacity of system is exceeded?

Post by bohica2xo »

Yeah, I think I said as much in his other thread a few days ago. Build a bypass pipe to replace the POA and test the system performance.

You could add a bung to the bypass tube and install an adjustable LPCO...
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Re: What happens when capacity of system is exceeded?

Post by Tim »

Thanks for spamming our site.
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cyfi66
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Re: What happens when capacity of system is exceeded?

Post by cyfi66 »

DetroitAC wrote: Tue Aug 31, 2021 8:08 pm Why wouldn't the current TXV work? Why do you need to put in an H block?

I don't agree that you NEED a cross charged head or bleed seat. You have a nice big fixed piston compressor, system charged head or cross charged would both work fine, whatever your existing valve head is will work fine. This compressor is incapable of low loads, oil return is not an issue.

H blocks are cheaper and more reliable, more assembly friendly than your externally equalized right angle valve, but it will be a major pain to adapt lines, and for no benefit that I'm aware of. Chime in if there is a benefit I'm overlooking.

Seems like you need a suction line without an EPR, the EPR was assembled into the existing line, so maybe it comes out easy or maybe it'll be destroyed, but that seems ok. Yank that suckered out and you have a perfectly routed suction line with an already built port for the external equalizer.

All that will take some work is rigging up a way to cycle the clutch to keep the evap from freezing up
I guess no advantage besides the fact its easier to find specs on them and there are a ton of options. I also like the idea of being able to flush the evaporator without pulling the dash apart (and being able to replace the TXV without pulling the dash apart). But its not really necessary. If I could find a drop in replacement TXV that was 2 ton and internally equalized I would much rather do that since it would be easier. I don't really see any 2 ton metric TXV's that are internally equalized though. I'd rather not use the OEM valve because it has the external equalizer that really only seems necessary because of the EPR (which I'd be getting rid of) and I don't know what the specs of the OEM valve are.


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cyfi66
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Re: What happens when capacity of system is exceeded?

Post by cyfi66 »

What do you guys think about going with this valve? It is one of the few 2 ton right angle valves I could find in catalog. It is also internally equalized and reverse flow (so the orientation will be the same) but the fitting sizes are different. I will have to weld on the appropriate fittings to my lines to attach to this valve.

The lines in my care are male insert o ring with the inlet being M16x1.5 and the outlet being M22x1.5. I cant find any 2 ton valves with these fittings.

The reason I would want to go with 2 ton instead of 1.5 ton is since I am trying to get the fastest cooling possible I want the valve to be able to flow enough refrigerant on initial startup when the valve is wide open (high heat load).

https://www.4s.com/en/ecatalog?partdetail=38869&view=bg

Tim I am not sure if you'd be able to find an alternate source for this same spec valve? Id rather not buy a four seasons product if it can be avoided :). This valve appears to be for an early 90s Mazda.
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