oil return, manifold servicing, et cetera questions

[teyber]

hey!

thought i would combine a couple questions i have into one thread.

1) i have a small leak i can't find and im pretty sure its in my new manifold. The fact that this is a yellow jacket and i also had a jb one leak tells me its more then bad luck :mad:

What servicing must be done? i remember jinu saying something like he needs to clean his every couple weeks or it leaks, but unfortunately i couldn't find exactly what he said and hes not posting on the open forums lately.

So what do you guys do? what do to if it is leaking?


2) Ive been playing with and idea i dont' want to say yet. But the questions is about a accumulator. Would a large-ish diameter tube with a inlet flush on the bottum and a outlet flush to the top, would this be a oil trap?


3) All my systems ive played with lately are acting like they have non-condensables in them. I leak test, vacuum for VERY long periods of time, purge all lines, et cetera. How often do you guys find considerable amounts of air getting into system when your unit is leak free? On my single with a ne2134gk its acting like i have a leak in the low side sucking in air as each tiem i use it the high pressure climbs and capacity decreases, but i put pressure in it doesn't hold pressure, but soapy water shows no love? (which brings me back to thinking its in the hoses?)

please keep this OT.

thanks in advance.

Note- to killermiller- i think i am having the same problems you are on your first single stage but i couldn't figure out what you did different to stop this?

reed

[n00b 0f l337]

1) i have a small leak i can't find and im pretty sure its in my new manifold. The fact that this is a yellow jacket and i also had a jb one leak tells me its more then bad luck

What servicing must be done? i remember jinu saying something like he needs to clean his every couple weeks or it leaks, but unfortunately i couldn't find exactly what he said and hes not posting on the open forums lately.

So what do you guys do? what do to if it is leaking?
Could flush, or try a super solvent, many options there. I would pressure test it.

2) Ive been playing with and idea i dont' want to say yet. But the questions is about a accumulator. Would a large-ish diameter tube with a inlet flush on the bottum and a outlet flush to the top, would this be a oil trap?
Probably if the diameters big enough.

3) All my systems ive played with lately are acting like they have non-condensables in them. I leak test, vacuum for VERY long periods of time, purge all lines, et cetera. How often do you guys find considerable amounts of air getting into system when your unit is leak free? On my single with a ne2134gk its acting like i have a leak in the low side sucking in air as each tiem i use it the high pressure climbs and capacity decreases, but i put pressure in it doesn't hold pressure, but soapy water shows no love? (which brings me back to thinking its in the hoses?)
That sounds like your hoses.

[captaincascade]

you need a micron gauge to test for a propper vacuum, under 200 microns for your purposes. do you know where its leaking? pressurize the gauges, make sure all the hoses are screwed to the back, and dunk the whole thing in water. look for bubbles.

Also i doubt you guys check or change your hose gaskets enough.

they sell new valves and new gauges for manifolds. ill get you what u need


make sure the gauges are dry before u use them !!!

[Spoobs]

when ur not running your compressor, you could use soap and water and look for bubbles. Same principal as dunking it under water except without submerging it. Not as accurate.

do you still have ur manifold hooked up to the unit when ur pressure testing them. "hose issue" could 24 hours hooked up to those rubber hoses really have that much impact? on the systems pressure...

[wdrzal]

.

Also i doubt you guys check or change your hose gaskets enough.



I bet most over tighten them also ,crushing the gasket.



As long as your low side is above 0 psig it can't draw in air. Only when running the low side in a vacuum can you draw air in.......


Answer to #2 yes it would be a oil trap, The oil is in "solution" with the liquid refrigerant but is swept along when the refrigerant is in it's gaseous state. Usually a velocity of approx. 400fpm is recommended.

If you have long vertical piping,then you need a higher velocity (that doesn't apply to these small systems)


If your system does not hold pressure you have a LEAK, either in your system or your manifold/equipment or connections. You pressure test first with nitrogen, then when vacuuming your micron meter also is a pressure test. If you show a leak you stop and find it & fix it. You don't move on............

Try getting a bottle of leak detector fluid, it has a higher viscosity & surface tension. It doesn't run off like soapy water does and the smallest of leaks will show. sometime it takes many minuites for even a small bubble to appear/grow.

[teyber]

you need a micron gauge to test for a propper vacuum, under 200 microns for your purposes. do you know where its leaking? pressurize the gauges, make sure all the hoses are screwed to the back, and dunk the whole thing in water. look for bubbles.

Also i doubt you guys check or change your hose gaskets enough.

they sell new valves and new gauges for manifolds. ill get you what u need


make sure the gauges are dry before u use them !!!

yes i have a micron gauge, a supco vg64. its risen to 1600 with the high side, the low side and vacuum pump lines open (but valve on vacuum pump closed). i have the line to the nitrogen cylinder closed because my regulator's connection leaks a bit, im talking if i hook cylinder to system and pressurize i loose like 5psig over night (nothign to worry about the regulator).

good idea- would it hurt the gauge though? its quite expensive. i like your thinking though, you thinker :up:

abotu the oil return- won't the oil form solution with the refrigerant? if theres no restriction i wonder if oil can make it straight uphill, just agaisnt gravity. (mean doesn't oil have to transfer up in lots of places?)

If the manifold is leaking, what would you recomend? i gotta finish naekuh's unit and im guessign the rma will take some time...

Hopefully its just the hoses... leaky manifolds s*ck

[wdrzal]

Oil is in solution in the liquid phase, not in the gaseous phase........If I use 400 fpm for horizontal velocity, I use 600 fpm for vertical,of course this is just a general statement,length of run ,mass flow and tube size also dictates this.

Keep in mind Bernoulli principal ,as velocity increases pressure decreases, when velocity decreases pressure increases. So a large diameter accumulator (in a vertical position)would slow the velocity of the gaseous refrigerant,when actually you would need a higher velocity to sweep the oil vertically upward. There are many accumulator designs but many use a J tube with a small hole at the bottom of the J to meter oil back to the compressor.

[teyber]

hey walt you edited your post-

I rebrazd 2-3 joints (added accumulator) and was very satisfied with the joints so i quickly pressure tested and moved on (doh)

Would it be bad for the compressor if in the bottum i drilled a hole and had a length of cap tube going into the service valve of the compressor? would enough liquid come back to harm it?

[captaincascade]

hey walt you edited your post-

I rebrazd 2-3 joints (added accumulator) and was very satisfied with the joints so i quickly pressure tested and moved on (doh)

Would it be bad for the compressor if in the bottum i drilled a hole and had a length of cap tube going into the service valve of the compressor? would enough liquid come back to harm it?


you want to drill a hole in the compressor?

[teyber]

you want to drill a hole in the compressor?

no was thinking a 1/16" or so hole in the schrader valve side, braze in cap tube?

[teyber]

here- will this trap oil? would this help me gain or loose capacity?

http://i198.photobucket.com/albums/aa15/teyber/DSCN2475.jpg
http://i198.photobucket.com/albums/aa15/teyber/paint.jpg

[wdrzal]

I think your trying to design a solution for the problem instead of diagnosing the problem and fixing it......

You should be carrying enough superheat to boil off any liquid in the suction line. Unless your tunning or charge are way off and liquid refrigerant is pouring through the evap and into the suction line. At full load you should only see a occasionally drop or two of liquid refrigerant leave the evap every few seconds at most. Otherwise you have a flooded evap instead of a wetted evap.

[n00b 0f l337]

I think he is concerned about the unloaded evap.

[teyber]

I think your trying to design a solution for the problem instead of diagnosing the problem and fixing it......

You should be carrying enough superheat to boil off any liquid in the suction line. Unless your tunning or charge are way off and liquid refrigerant is pouring through the evap and into the suction line. At full load you should only see a occasionally drop or two of liquid refrigerant leave the evap every few seconds at most. Otherwise you have a flooded evap instead of a wetted evap.

i understand 100% where you were coming from if this unit was being tuned for exactly x watts at a cpu which produces exactly x watts... this is going to be in a unit for somebody who uses a huge variety of cpu's... will need to handle 240w range but most likely lots of dual cores not just for benching but for daily operation. definately not an option not to have one

[wdrzal]

With-in a given range ,a cap tube system can compensate for different loads.

[teyber]

With-in a given range ,a cap tube system can compensate for different loads.

im talking 45nm duals and a 8 core he has now... let alone whats in the future

[wdrzal]

hey walt you edited your post-



Just added more info and answered some of your other questions.:up:

[wdrzal]

im talking 45nm duals and a 8 core he has now... let alone whats in the future

Talk in terms of heat load, oh you can't as I doubt anyone really knows for sure,(unless the manuactuer releases the thermodynamic properties). most of what I see are just estimates,and all over the place. I'm sure there are test points on the mobo where voltage and current can be measured to the CPU.

You can't determine heat load by clock cycles.

[DetroitAC]

Gauge manifolds are serviceable equipment, and not something you RMA. They occasionally develop leaks, you find the leaks and fix them. If you want to RMA your manifold everytime it leaks, you won't ever own one for more than a few years. There are repair kits to fix the valves, and the connections are often pipe thread and can be taken apart, new teflon applied and reassembled.

You may want to review your evacuation and charging procedures to make sure you aren't systematically introducing air at some point.

Regarding your accumulator, it doesn't even look to me like it will hold any liquid at all, maybe explain more or post a better cartoon?

[teyber]

Thanks DAC :)

- ill look into a repair kit... thanks for the heads up. i knew it was something like this but i never hear of other people on the forums complaining about manifold leaks so i thought i would ask a technician.

- I have had a long talk with boshuter, and drewmeister and i don't think im missing some thing obvious...

- Rather then it being like a commercial accumulator i was more hoping to use some heat from the high side to help boil some liquid- more of something that "sounds good in head" but may not work well at all.

walt- ill re-read thanks :)

In terms of safety of not using caps on this but instead pluging it with copper bar- Would this be safe? its 1 5/8" diameter, 1.5" inner diameter, 3" long.

Reed

[wdrzal]

Thanks DAC :)

- ill look into a repair kit... thanks for the heads up. i knew it was something like this but i never hear of other people on the forums complaining about manifold leaks so i thought i would ask a technician.



DAC: how are you going to explain your Demotion to your wife.....guess you'll have to knit her a sweater this year for Christmas. :eek:

[teyber]

DAC: how are you going to explain your Demotion to your wife.....guess you'll have to knit her a sweater this year for Christmas. :eek:

:p: i ment somebody who does this for a living, teki

[teyber]

dac-

http://www.hvacr-tools.com/mm5/merchant.mvc?Screen=PROD&Store_Code=HVACR&Product_Code=41099&Category_Code=
is there a cheaper model? I mean i would buy it if it looked like it contained $130 worth of stuff :p:

[wdrzal]

dac-

http://www.hvacr-tools.com/mm5/merchant.mvc?Screen=PROD&Store_Code=HVACR&Product_Code=41099&Category_Code=
is there a cheaper model? I mean i would buy it if it looked like it contained $130 worth of stuff :p:

You haven't even determined where the leak is yet !!!! How do you know you even need parts ?????? :shrug:


That kit contains parts to rebuild multiply manifolds.

[DetroitAC]

Teyber, I'd take Cpt. Cascade's advice of dunking your manifold to find out if it's leaking. Water has a huge surface tension, so it may take quite a bit of time to develop a bubble if it's a small leak. Better wetting fluids will form a bubble that can break free faster, but you won't go wrong with water and patience. I use Swagelok snoop or windex to find leaks, but really tiny pinholes, I can sometimes find them easier with a leak sniffer.

I know I turn a lot of wrenches, but I'm still called an engineer on my paycheck.:up:

Regarding your accumulator, it's not going to "accumulate" if you are boiling the liquid off. But it doesn't look like it's going to accumulate anyway because the outlet pipe runs out the bottom. There is some confusion I think on what an accumulator does.

There are two functions really, and an accumulator can do either or sometimes both:
1. Protect the compressor from a transient liquid slug. This can occur if you have complex system with valves and solenoids that may open at any time. The accumulator may operate with only superheated gas and oil for 99.9% of the time, until things go wrong and a liquid slug is sent in. It'll capture the liquid and let it boil off slowly. This is a good place to use an accumulator with a liquid line heat exchanger in it. The liquid line will help boil off the liquid, but will also perform the SLHX function and may keep the accumulator shell warm enough so that it doesn't sweat.

2. Store excess liquid refrigerant. As far as I know only automotive systems do this. Maybe someone could explain if there are other systems... By that I mean an orifice tube/accumulator system is designed to have a lot of liquid stored in the accumulator at all times. In order to store liquid, it has to remain at the saturation temperature of the accumulator. If you insert a heat source like a liquid line (SLHX), it'll all boil off and go elsewhere (the condenser).

[wdrzal]

I know I turn a lot of wrenches, but I'm still called an engineer on my paycheck.:up:





My Dad used to tell me never trust a Engineer who never had grease under his fingernails or a Captain (Boat) who enjoys swimming. :D

I guess DetroitAC's wife might get a new car for Christmas, possibly with a Transcritcal A/C system. On Second thought,she may already have one of those. :up:

[teyber]

here is what i did-

Capped the low side of system

Hooked up a hose to a pressure gauge

holding 259psig for now :) system im 99% sure is leak free.

So i got my two shortest, but expensive yellowjacket hoses and hooked them up. I dunked the hole thing under water and i see bubbles emerging from the hose itself.. a little bit on the fittings but the actual, rubber, yellow HOSE! im talking quite a bit of air coming up in countless places on both hoses. This is why you don't use hoses as a suction line!

i think i need some r134a hoses... :/

[one_servant]

Man, I know your Yellow Jacket hoses aren't that old...I'm very surprised that they already have leaks in them. I wonder what has caused this issue this short into their use.

On another note...I just dropped some bucks on some r134a hoses and I didn't want to do it either...I feel your pain.

[n00b 0f l337]

Why r134a hoses?
Why not get some nice hoses with quick disconnects already on em.

[teyber]

Why r134a hoses?
Why not get some nice hoses with quick disconnects already on em.

r134a hoses have a more dense material, so less gas can exit.

and yer very odd...

[n00b 0f l337]

Ah, didn't think of that, well that's fine, my yellow jackets don't seem to leak at all...

[teyber]

Ah, didn't think of that, well that's fine, my yellow jackets don't seem to leak at all...

i wouldn't either but i pressurized it adn dunked it in water and... I saw lots of driplets of water coming from the hoses. the pressure didnt' drop much but i was seeing gas come from the hoses. they were about 2 months old.

R.I.P. i wonder if i can rma -_-

[n00b 0f l337]

Well mine have sat with pressure in them for weeks without losing a spit, so yours might have just been worse seeing as you seem to have uncondensable problems.

[yngndrw]

How do you store your hoses ?

[teyber]

How do you store your hoses ?

i wrap them around the water heater why?:shrug:

[n00b 0f l337]

Store? One build to the next alot of the time.

[teyber]

i wrap them around the water heater why?:shrug:

this was a JK btw:p:

all my piping and hoses go around a peg i have in the corner of the ceiling

[yngndrw]

:x Could they be bent too tight around the peg ?

[teyber]

nah they are hung up loosely. If you looked at these hoses under a microscope i doubt you would see a hole. (well maybe a electron tunneling :p: )...

[wdrzal]

Like I said before, many companys make a premium and a cheaper hose, that includes name brands.

Also you must be aware of Fake name branded hoses.

[[XC] 2long4u]

Teyber, I'd take Cpt. Cascade's advice of dunking your manifold to find out if it's leaking. Water has a huge surface tension, so it may take quite a bit of time to develop a bubble if it's a small leak. Better wetting fluids will form a bubble that can break free faster, but you won't go wrong with water and patience. I use Swagelok snoop or windex to find leaks, but really tiny pinholes, I can sometimes find them easier with a leak sniffer.

Or use vodka then you can drink it after you find the leak.


r134a hoses have a more dense material, so less gas can exit.

and yer very odd...

R134a hoses are barrier hoses. A barrier hose is a plastic lined hose. You can make your own hoses as ling as you use barrier hose.

[teyber]

gar- well i have tried all my hoses on the system im working on and its leaking. i completely re-worked the system and still leaking. i finally just went to leak testing from 1 side and capping the other and i tried multiple gauges (not manifolds). lol i guess the system is leaking. simple soap and water gave me no love as usual.

I have cheap and very expensive hoses. my vacuum pump hose cost me over 40$ for the hose itself. i think all my equipment is in need for a severe pressure testing in the bath tub. what should i use to decrease surface tension? a bit of unpure isopropyl?

Right now time is money, not as much time to work once SCHOOL starts up so i have a TIF rx-1a im thinking of buying. well see.

also detroitac- i have spent quite a while searching for a "manifold repair kit" but nothing comes close to what you are talking about... anything your shop might be able to order and you can jack up the price for me or a link or something?

Reed

[[XC] 2long4u]

Simple solution.
Drive up here we will have it hammered down in one night. :p:

[teyber]

im actually in san fran right now :) not practical to take a day up though lol. there is a cheap lathe in your area and my mom shot the idea down pronto :(

[[XC] 2long4u]

Oh thats fuked up. You are less than 2 hours away and you don't say anything.
I see how it is. What are you doing there?

[teyber]

2long4u;3224244']Oh thats fuked up. You are less than 2 hours away and you don't say anything.
I see how it is. What are you doing there?

family then the hippie town of mendocino :)

[DetroitAC]

also detroitac- i have spent quite a while searching for a "manifold repair kit" but nothing comes close to what you are talking about... anything your shop might be able to order and you can jack up the price for me or a link or something?

Reed
I know a few of the refrigeration suppliers here have kits on the shelf, I'm not sure if you will be able to order them online. Check the Yellow Jacket website, lots of replacement parts there.
http://www.yellowjacket.com/HVACRProducts.asp?l=5&t=HVACR&c=39

[teyber]

I know a few of the refrigeration suppliers here have kits on the shelf, I'm not sure if you will be able to order them online. Check the Yellow Jacket website, lots of replacement parts there.
http://www.yellowjacket.com/HVACRProducts.asp?l=5&t=HVACR&c=39

gotcha:up: thanks for the link. ill try to go to johnstone as soon as i get back. im now thinking the manifold is fine but i have another manifold thats really leaky.

Also i won the TIF rx-1a for a very fair price imo. not a great price but im happy with it. lets see how leak detectors work:cool:

[wdrzal]

Soap reduces surface tension :up:

It's a tough learning curve if you have someone to guide you. Learning on your own just compounds the problems.

I had new YJ hoses blow out the first time I used them........

[teyber]

well i got the leak detector :) not the greatest price, $100 shipped, i missed one the day earlier for $75 plus 15 to ship. meh 10 bucks, o well. its brand new :)

hope this saves me lots of time. i put soapy water on every joint and didn't get a bubble, so i think its either in flex line or in the condenser? (god i hope not, if it is im SCREWED!)

walt what hoses do YOU use? i am wondering about the stainless ones, but they are just so expensive. i have a set of bacharach(cheap), a decent set of JB hoses, and 2 YJ ones...


Off topic- all of gray moles pics are broken. anybody have his accumulator design?

[wdrzal]

Usually YJ premium II ,sometimes robinair,just where I,m at when I decide to buy more.

Check the gaskets in the ends if you over tighten them they will crush and leak.

That the bad part of buying hoses off ebay, you never know if they sat on a shelf for 15 years.

[killermiller]

I think you may need to reevaluate your troubleshooting a little. There seems to be too much going on, and everything can't be failing.

The hose is made of layers, the outermost(red/yellow/blue) is for protecting the airtight portion of the hose. Not to say is wasn't leaking but if it was leaking the chances of it leaking the entire length is not likely. People around here use their hoses much more often than you or I and haven't had any trouble.

Get yourself a cheapy gauge and one of these (http://www.hvacr-tools.com/mm5/merchant.mvc?Screen=PROD&Store_Code=HVACR&Product_Code=19110&Category_Code=COUPLERSADAPTERS). Make sure you have a cap on one end and this on the other. This will eliminate you points of failure by 50+%.

I had trouble with my flex. It would leak faster depending on the positioning of it. My system had about 10 baths before I finally scrapped the entire flex. Between that and my Imperial manifolds, It took my build far too long. I bought all heavy duty hoses because I thought my hoses were leaking but it was the manifold and flex the whole time.

[teyber]

walt- i bought all my hoses from hvacr tools...

killermiller- im not sure what i would use the quick connect for- just looks to be a 1/8" to 1/4" converter? do you mean just attach a gauge similar to ones used on cascades to one side and cap off the other?
i hear you. as soon as im home im going to spend a bit of time searching for leaks. i also doubt both hoses would be leaking...

reed

[killermiller]

The thread on the gauges are 1/8npt so it just screws right in there. 2 connections as opposed to 2 for 1 hose, gaskets in the manifold, plus whatever else. Sure beats wondering if your manifold or hoses are leaking.

I was assuming to have two access ports on the system, so cap on side and pressure test on the other.

[wdrzal]

Check around the valve stems on the manifold,occasionally the nuts there need snugged up.