Quick Disconnect Fittings for Refrigerant Gas

[Angela]

I read somewhere, or heard about this somewhere, that there are some kind of quick disconnect fittings available for refrigerant lines so that when you have to work on something, you can un-do the quick disconnect without losing all the gas and without having the purge and recharge the system.

Has anyone used these things and where I do find them? I have four evaporator/blower units running off one compressor. When I want to work on one, I have to evacuate the entire system and then have a AC tech come out and recharge it for a million bucks every time. That getting old. I’m going to build two new manifolds that distribute the gas to the four units via solenoid valve and while doing so, if I can set this up with those quick disconnects, that’s what I want to do.

I would appreciate any direction you guys can give me on this. Thanks.

 

[TedZ]

I don't think they exist.

One way it is done is to use valves in the lines to the manifold. That is the way they used to do pre-charged lines but even they have disappeared due, i assume, to the tiny leakage you can get and maybe the problem of getting enough 134 in a line due to the higher pressure and the slight air contamination.

My $.02.

Ted

 

[yachtsmanbill]

Hi Ang!! Look in McMaster-Carr. Since your making a new manifold, you should be able to buy sweat on isolation valves. Generally, they are a T fitting with a schraeder valve built in. You may not find a female to male adapter and might have to make one.
Go junking and find some old junk cruiseair units. Mine have them... Unscrew the black caps and there is a valve stem underneath it. These are in and out with the schraeder valve on the side ;-) ws

 

[Boatsb]

They do make them but they will not solve the problem. You need to get valves to Isolate the systems ( high and low pressure sides ) and also get a vacuum pump, Gage set and a freon tank. I have only needed to evacuate my home system when I installed it. The boat never had a problem needing evacuation just filling once because some idiot left the valve open a tiny bit.( I caught crap for days). As long as the lines are not broken and the pressure in them is more than the air they will not need evacuation.

 

[Angela]

I’m not trying to make a CruisAir part, so looking for CA scrap won’t do me any good. It is my understanding they only used this system on the Series I, 58MY. It wasn’t Hatteras’s most proud moment, but this is what I’ve got.

I’m trying to make something so that when I have to replace or repair one valve, I don’t have to remove all the gas. I have one refrigerant line coming out of the condensing unit. It goes to a manifold with four solenoid valves where the gas is distributed to each of the four staterooms when each room calls for cooling - the valve opens and closed to allow refrigerant to flow to that room. Each stateroom is independently controlled by the occupants of that room, but all of them run off of one condensing unit. When the thermostat is satisfied, the valve closes, shutting off the refrigerant to that room. It could well be that that same condensing unit is still supplying refrigerant to other rooms.

There is another manifold of four valves that works in unison with the other set. Hence, there are 8 valves to provide endless opportunities of failure and headaches.

Currently, I have one valve I need to screw with. That means I have to lose the entire AC system and call someone out who can recharge the system. I can’t buy the gas on my own. I’m trying to cut the ties to AC people since most of them are friggin clueless about this system.

It’s an odd system that didn’t really perform to Hatteras’s expectation which is why you don’t see it in other boats. The alternative is to run 7 compressors and I don’t have the amperage for that. So, I’m stuck with this. I’m just trying to may it easier to work on. Maybe that’s not possible without having to become a licensed AC tech (so I can buy the gas).

 

[Finalee]

Angela, you may want to get you're license. You can get certified and then order freon and supplies via this site. http://www.r22.org/index.php

I did it in May. The test took 2 hours. I copied the license online, scanned it and ordered the supplies needed alll the same day with the newly aquired license.

 

[Boatsb]

Angela the test is not that bad if you need to get the license. I know people who are licensed and they showed me the test. If you need you can buy gas on line as long as it is for resale. Just like fireworks in Brevard county are for agricultural use. Sign a paper and done. The gauges and the pump are the other things you need. Some people even evacuate the system into a tank and refill it from it too.

The original system in my boat was 2 staterooms running from a single compressor with 1 master and one slave. The master set the temp that either would drop to and the slave had a fan control so the occupants could control it to a point. The PO removed it so I can not tell you how it works YET because I plan on re installing the missing parts and going back to it.

There were no valves to worry about and the master temp was only set from one control but it seemed to be a sound idea. Could you simplify yours by following that type of design?

 

[DeeRow]

Have you thought about a chilled water system?

As I understand it, it is just like your system accept chilled water is circulated instead of gas. Removing old piping and replacing it with new piping sounds like a major pain. I wonder if you could use your existing A/C pipes. I inquired about this system at a boat show because I have 3 self-contained A/C units on my boat and have entertained adding a unit to the bridge. I barely have enough power for 3 units so adding another will be an issue. I was told that they are only pratical on larger boats. I think 58 foot might qualify as a larger boat. I have no idea what this costs as the person in the booth felt very strongly that it was not a good fit for my boat. One issue was the space required for the pipes. You already have pipes, so it might not be an issue.

Mark

 

[Angela]

There were no valves to worry about and the master temp was only set from one control but it seemed to be a sound idea. Could you simplify yours by following that type of design?

I wouldn't want to do that. The areas being cooled by this system are quite diverse. It's just too much space to have one room controlling the entire area. It consists of the entire lower level of the boat - 4 staterooms. Two staterooms are under the bow decking in the sun and get hotter than others, while the other two are under the salon and galley, with one of those being next to an engine room. These staterooms really do need to be individually controlled by the occupants. I'll never get 8 people onboard with the same internal thermometer and have them all be comfortable.

 

[krush]

Like bill said, you are talking about isolation valves. Commercial and split systems (like heat pump in your house) usually have them around the compressor or the outdoor unit so you can isolate it to swap out compressor.

What you could do is put on some isolation valves on either side of your manifold. Then you could isolate the valves from the system anytime you need work on it. Put on a service valve to pull a vacuum and you good to go!

 

[Angela]

What you could do is put on some isolation valves on either side of your manifold. Then you could isolate the valves from the system anytime you need work on it. Put on a service valve to pull a vacuum and you good to go!

This is where my thinking is!

 

[yachtsmanbill]

Thats what I was trying to impress Ang!! Since youre building the new manifold and have become adept at soldering, get a bunch of these valves and isolate the manifold. ws

 

[krush]

Thats what I was trying to impress Ang!! Since youre building the new manifold and have become adept at soldering, get a bunch of these valves and isolate the manifold. ws

We said the same damn thing, I just said it better