It is mixed with the freon for the most part, and does accumulate in all components in small amounts. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. The next piece of equipment to track down leaks is a leak sniffer. R134a. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Hi pdrayton- If you can remember the oil capacity that you found in all your research and post that, then bohica and others can have a better idea if you have too much; see if you can find that info! Welcome to rxmechanic.com. It slowly gets warmer and warmer in the car, even at highway speeds. It is possible I have 10 ounces (250 ml) in the system. we convert older systems where i work all the time and they work fine. Can I just use an adapter and save $200? At this point it is time to make an appointment with the a/c shop. Also the new quick connect fittings for the high & low side. Is there a difference in the expansion valve for R12 as opposed to R-134a? Is there a graph? "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. They have no moving parts. BTW, I use a stick thermo in the vents and the laser on the condenser. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. Are r12 and r134 fittings different? The difference between the two is about 10,000 btu/h. Electric fans do wear out. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." . There are other refrigerants: some of which may work, some of which dont work, some of which will destroy your a/c system and some of which are dangerous. I don't think it has any air dams or seals, I'll check to make sure. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. I'm thinking I might have put too much oil in the system - everywhere i read had a different amount - the manufacturer of the compressor, the MB factory service manual, online forums. What is a T/C?4. The AC usually does not work at all. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. Minor adjustments to the expansion valve and other controls may be necessary for some plans. Crap! ). It does not "pool" to any degree in a large amount anywhere. As per their results . The condenser water inlet temperature and flow rate are controlled with the use of a . Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Jun 19, 2007. R134a and water have the same abilities to change the state but R134a can do this more rapidly and at a much lower temperature than water. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. In more serious, it could result in cardiac irregularities or death. With tube & fin condensors in MVAC applications there is never "too much" airflow. Any ideas from the info above? After the system has been tested out it should be checked for leaks. 3 ounces? R134a was selected as a replacement refrigerant for R12 because R12 contains chlorine and has a major effect to ozone layer depletion. I think the way to go here is1. Since there is only about a 10% difference between R-12 and R-134a, the expansion valve being self-compensating really doesn't make that much difference. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. System has been working fine for a year. Thanks so much Bohica - you've save me many more hours of fruitless speculation. R1234yf is more environmentally friendly and has a global warming potential of 4. Please enter a valid email address for yourself. B. 2022 nba 2k22 starting a fashion label signing the designer, a difference between r12 and r134a expansion valve, 2020 white paper of the church of pentecost, Chime Mobile Check Deposit Funds Availability, Why Does James Kill Donald In The Vanishing, nba 2k22 starting a fashion label signing the designer. We suggest dumping the old refrigerant oil in a clean container and inspect the oil for sludge or waxing (old oil that has gelled) and contamination (metal particles). The MB chart shows 360 psi with R12 in some conditions. Safety: R134a is safe to use as its non-flammable and cant explode. I'm having the same concern. Participate in over 40 different forums and search/browse from nearly 3 million posts. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. The system will be checked for gross leaks while under vacuum. They examined the two configurations of capillary tubes i.e. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. Thanks again. 34 in 70 series w/ R12 in 100+ Tucson, AZ summer heat w/ hd-t, w/ 13B-T is was unbearable about 31 at vent w/ R12. 4) Inconsistent Airflow. 37 in 2005 tacoma, R134A. I'm also thinking maybe I should go to R134 - it might work better with the right amount of oil and the correct expansion valve. Poc temps desprs van decidir unir els dos webs sota el nom de Xarxa Catal, el conjunt de pgines que oferirien de franc sries doblades i/o subtitulades en catal. Questions About Becoming A Professional Member? shown for the parallel flow, aluminum condenser that is listed. The difference really shows up on the high side. The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. For R12, its mineral oil. I don't have the FSM matrix handy for that 123.123, but a 123.133 shows a test rpm of 2,000 - and vent temps between 54f & 66f at 91f to 95f ambient. Since you will be using less R134a than R12 you do not want to rely on the driers site glass to determine if the system is full. If the system was upgraded by a professional it should have an upgrade sticker. If 50 degrees across the cond. Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . difference between r12 and r134a expansion valve. These efforts to balance the system can not be realized if there are problems within the a/c system, such as: poor performing compressor, dirty condenser or poor air flow through the condenser, malfunctioning expansion valve, water or air in the system, improperly operating fresh air or heat input in the climate-air mixing system. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . You are indeed 20% out of the OEM spec for cooling. Please enter the name by which you would like to log-in and be known on this site. Environmental Impact: When R134a escapes into the atmosphere, it contributes to global warming. I am ordering new parts, and planning to convert my system to R-134a. Stability: RR12 doesnt disintegrate even under extreme operating conditions. It won't be optimal, though.On some/many valves, you can adjust them, but that might make matters worse unless you really know what you're doing (which I don't!).RegardsGeorge. It has already been clearly stated that R12 is a chemical that damages the earths ozone layer and shouldnt be released into the environment no matter the circumstance. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." Table 1 summarizes the technical characteristics of three potential R134a alternatives. However, R134a is better than R12. It won't be optimal, though. don't know enough about the subject to explain the choices.However, a few days ago I called the dealer to see about an OEM TEV and they said something that made me feel a little bit better; the same part number superceded every application back to the '60s, and that they couldn't do that without engineering signing off on it.Still, I would feel a lot better if I could see something written officially that compared the flow characteristics and performance of r12 and 134a TEVs are concluded that they were interchangeable in automotive applications.If someone knows of such a document I would sleep much better!Walt Edited: Mon September 12, 2005 at 8:13 PM by wamcneil. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. I recommend replacing the expansion valve when you do the swap. Also, R134a cylinders are light-blue in color. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." Most of all the differences gravitate to longevity, functionality, and safety. Also called the orifice tube. Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. Can I order a valve based on the original eaton number? The ratings for evaporator temperatures 40F, 20F, -10F, -40F in the capacity tables are in accordance with ANSI/ARI = R134a Charge Level R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? Generally you follow the refrigerant flow moving from connection to connection, component to component, and you sniff the a/c vents to check for evaporator leaks as well. R-12 expansion valves can be re-used, but will not be as efficient as R-134a specific ones because of the slightly different pressure specs of R-12 vs. R-134a. R134a Refrigerant Recharge Kit with BPV31 Bullet Piercing Valve and R134a Quick Coupler, R134a/R-12/R-22 Freon Refrigerant Hose Can Tap Kit for A/C System - Easy to use. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. I'm just trying to help you avoid headaches in the long run. R134a is the most widely accepted alternative automotive refrigerant used to replace R12. The major reason for the replacement of R12 with R134a was to curb future greenhouse effects. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. Is there a source of valves by, say, eaton number? Most vehicles manufactured before 1993 have the R12 A/C system. When I compare parts, 93 uses one part number and 94 has a different part number. The expansion valve is designed so that the temperature of the refrigerant at the evaporator outlet must have 8 to 12F (4 to 7C) of superheat before more refrigerant is allowed to enter the evaporator. So, instead of using R12, other better options include R401b, R134a, R401a, etc. Interestingly, theres one oil type that works perfectly with both types of refrigerants. of coiled cap tube on VCR system with R134a. MB has specfic test parameters for performance, but you can always test at max load - doors open fan on highest speed.The oil overcharge looks like a parabolic curve. Blows pretty hard on full. Recharge the compressor with a/c ester oil and a tracer dye. Nice to use new gadgets! The only material difference between automotive A/C and a window A/C unit or refrigerator is that in the home application, the components are all inside the same rectangular box, but in the automotive application, the components are distributed throughout the car. Unfortunately, the oil only mixes with the refrigerant as a liquid. June 21, 2022 difference between r12 and r134a expansion valve . Besides, R134a refrigerant was manufactured after R12 was banned to help reduce the harshness of the old chemical (R12) on the ozone layer. Any advice appreciated. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. By noting the ambient temperature you can look up what the preferred high side pressure should be. . Just leave it alone for now. Even though their common major function is to cool the system, they have many differences. How is 1234yf different from . It was later found that R-134a had a very high Global Warming Potential, or GWP, number. Paul:It is never a waste of my time to chat with someone that understands the problem, and wants to fix it. Yes, this was a smokers car. I dont know why the cost difference between compressors is so huge, though. If there is no pusher fan, and you have the room, put one in. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? For those of you who are considering what the cost is for R12 you can think of it this way: Dont go out to dinner this weekend. With the oil leaking out and being told all sorts of things about how these compressors don't have a sump etc, I wanted to be on the safe side. Bottom line, R134a simply doesn't cool as well as R12. The oil is spread all over your system when it is at rest. It is usually sold under the brand name, Freon 12. One of the differences between auto air conditioners that have been redesigned from R12 to R134a is that the condensers have gone from serpentine to pseudo-parallel. The whole trick is to sit there in those steam boxes and not perspire, it's vulgar to perspire when driving on public roads.If you want esteem, drive an MB, if you want comfort with 60*F interiors in a 125*F environment, get a Caddy. Its cylinders are colored white. A thermostatic expansion valve (TXV) (see Figure 1) is a refrigeration and air conditioning throttling device that controls the amount of refrigerant liquid injected into a system's evaporatorbased on the evaporator outlet temperature and pressurecalled the superheat. Very nice! The bad thing is I don't know what to do about it. What is needed? What is the refrigerant property involved that has caused this? Its not that difficult but the procedures of evacuation, charging and testing should be done by a licensed a/c technician that is experienced with R134a and your particular car. Still, I have some simple green, so may as well give it a go. We sometimes use a relay switched from the compressor clutch to run fans. Besides R134a there are some other refrigerants that are approved to replace R12 and there is a long list of refrigerants that are not approved. By using a qualified a/c shop with the proper equipment you odds are in your favor of having the job done correctly the first time. Trinary Pressure Switch quantity. difference between r12 and r134a expansion valvewarning signs for a deteriorating patient with covid 19 infection 2022.07.03 18:36 18:36 Shorting the plug for the refrigerant switch should run the fan when the compressor is on. Compatible with multiple applications: The major reason for the introduction of R134a was to replace R12, so it functions perfectly in the same range of applications like rotary, screw, and centrifugal compressors for air conditioning and refrigeration. R-12 to R-134a Conversion. Rxmechanic.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for website owners to earn advertising fees by advertising and linking to Amazon.com. I put in a new (not reman) compressor (R4 I believe it is) in my merc 240D, new drier, new expansion valve, new o-rings, nylog. So the steps involved are cleaning out the old oil, replacing all the O-rings, replacing the dryer, replacing the expansion valve, and converting the high and low side connectors from Schrader to quick connect valves. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. In short, NO! Rules governing changing from the former to the latter differ between countries. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. You do not need to replace every o-ring in the system, but if you happen to open a connection that has an o-ring you should replace the old o-ring with one that is compatible with R134a and lubricate the o-ring with ac oil. Make sure to get the R12 EXP valve if that is the way you go. You do not need to replace the expansion valve in most cases. This implies that the discharge pressure of the compressor should be moderate so it can produce the refrigerants condensation in the condenser at the atmospheric temperature. The good thing is that after you convert to R134 you can top off the system easily and cheaply. You can use the R134a retrofit capacity chart for this purpose. Have a look in the FAQ Section, and look for "Fan clutches & testing them". I'm putting r12 back in my system, but all of the valves I can for the application (1990 jeep grand wagoneer) say r134a on them. With new R12 no longer being manufactured, the market price soared to $100/pound. ambulance tailgate conversion _____ 2012 E350 2006 Callaway SC560 . Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. We are an automotive mechanic blog that helps mechanics and car users to find the most recent and accurate technical and repair information for their cars. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. Took me a while to figure that one out, and how to say that. However, it was found to be a very bad gas for the environment. 10,000BTU conduction heating? R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. The Main change in the system is the expansion valve. R12 and R22 are both now banned by the EPA in the United States. R-134a XV for R-134a use. The name of the oil is Polyol Ester (POE). We've updated our forums!Click here to visit the new forum, Year: 1983Make: MercedesModel: 240DEngine Size: 2.4Refrigerant Type: R12Ambient Temp: 90Pressure Low: 35Pressure High: ?Country of Origin: United States, Hi, this is my first post, so please take it easy on the noob. And yes - expansion valves sometimes need replacing if they are sticky - but a proper AC flush should eliminate the need for a new one if it's already in good condition.
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