Leaking service valve

[airefresco]

We have a small 2.5kw R410a split system that has a leak. I´ve been to check the unit today and there was 50psi standing pressure in it. I last checked it out about 5 months ago, and It was Ok then.

All 4 flare connections look good to me and there´s no oil around them. There is oil around both liquid and suction valves though(under cap where you open/close the valve with an allen key). The caps were on tight, But still think it´s leaking from them.

I´ve been to the local wholesalers and they don´t sell the valves. Anybody got any ideas of where I might get a new one from, or possibly If i could repair the old ones.

paul..

[stuartwking]

Hi, what make of unit is it your working on?,Have you pressure test and provin the leak is from the shut off valves?,Just cause there is no oil at a flare not doesnt mean it not leaking,. I leak check fittings even if there is no oil trace, better to be safe than sorry,,.

[powell]

Parker makes them. There called "Base Mounted Shutoff Valves."

Example part number: QL171R-14-14 7/8"

Here's the link to Parker: www.parker.com

I couldn't find them on their website...............which I find quite difficult to navigate.

[airefresco]

Unit's a Tekion TK9000/HCS.

True, It could have another leak from the flare. I did go around with leak spray on the last maintenance and all seemed OK then. However, that was last year.
Surely the valves must be leaking if there is oil there. How else could it have got there?

paul..

[airefresco]

Thanks for the link Powell

[N.Lewis]

Just try tightening both valves, i have come across this before, one or both caps having oil in them, usualy a quarter turn wil solve the prob, then use soapy water to leak check.

[The MG Pony]

elecxtrical leak detectors are good for this sort of thing, picks up lot more then the spray.

[sinewave]

I've found leaking valves are getting more and more common nowadays!

The usual culprit is a distorted valve when torquing up the suction pipe on the condensing unit.

We've had a few that have started to audibly leak the pre-charged refrigerant out of the accumulator when we have yet to conect up the Air-handler!

[chris96]

Hi,

Your leak testing 410a with a standing pressure of 50psi? Maybe the leak occurs when the systems running at 400 odd psi.
You need to prove your leak, i've had loads of 410a units leaking, and all the time on the high side flare, undetectable until nitro tested.

Chris.

[Noori]

Hi
fully close the bothe valves then fully open it and use soapy water to leak check.

[nike123]

Almost all of these valves leaking when they don't have cap on them.
If you suspect that they leak with cap on them, charge them to specified weight and put unit in heat mode. Then check for leak with electronic detector. If they are leaking, put some Leak-Lock paste at contact surface of valve cap and then tight firmly. Check again with electronic detector. Works for me, every time.

[Brian_UK]

The other option is to cut out the valves and flares then replace by brazing in a section of pipework - no future leaks....

[paul_h]

Wind them fully in, drop some oil in there to expand the o ring, wind them fully out again, usually works for me. If it doesn't work, threadtape or leak lock the threads for the cap.

[airefresco]

Hi,

Your leak testing 410a with a standing pressure of 50psi? Maybe the leak occurs when the systems running at 400 odd psi.
You need to prove your leak, i've had loads of 410a units leaking, and all the time on the high side flare, undetectable until nitro tested.

Chris.

No, I meant that it had 50 psi in it yesterday. I checked the flares on the last maintenance visit when it had it's full charge in it.

Both valves were already as tight as they would go. Thats the first thing I tried. However, I didn't try and turn them all the way and then all the way out again.

I was actually thinking of just cutting the valves out and brazing the pipes on, but first I think try puuting some oil in there and a bit of thread lock.

They probably wont run in heating as it's too warm, but i'll give it a go.

thanks guys,
paul..

[Brian_UK]

They probably wont run in heating as it's too warm, but i'll give it a go.

thanks guys,
paul..

Put it in test mode.

[airefresco]

There isn't a test mode.

[nike123]

O, yes it is!
Stick that indoor air sensor in cup of cold water!

[Magoo]

this is basic refrigeration stuff. Get the proper flaring tools and torque wrenchs for 410 . 50psig standing pressure would suggest the system has a serious leak.
magoo

[airefresco]

@Nike123 - I remember doing that in England, though it was warm water to get the units to run in cooling in winter: I had forgotten about that.

@Magoo - Surely the unit would have no gas in it if it was a serious leak, no? There clearly is a leak though.

I´m starting to think maybe this thread has been taken the wrong way by some people. I don´t have a problem finding a leak or flaring or anything like that. All I was asking is, IF the unit is leaking from the service valves, as I suspect, what´s the an alternative to replace the valves? If not, then where can I get the valves from, as they don´t sell them in the local wholesalers? There´s been some good sugestions posted, of which I will try, If I prove the leak is indeed from the service valve.

[Andy W]

I pressure test everything with nitrogen, amazing stuff if used correctly. I used to overtighten high side flares and they leaked following pressure testing on new R410 sytems, I had to purchase a torque spanner in the end and I have been tightening flares for 30 years!

Regarding leaking caps, I wind the valve all the way out and then turn it back in a little.

[paddyaircon]

i would reccomend going back to the van - drive home and have a pint !

[paul_h]

i would reccomend going back to the van - drive home and have a pint !

With those problem solving skills and that user name, I'd be disapointed if you were not originally from ireland

[momo]

This problem is becoming more and more common with manufacturers making these valves "thinner" and "thinner" with recycled metals - one really has to get the touch right when tightening the nuts. Even good brand names can give one bad surprises.
Recover gas, replace them with a standard brazed refrigeration isolation valve in line and a T + scraeder on the suction line to the indoor unit, the rest is good standard practice...
Not as pretty as the original, but it will work.
PS some manufacturers recommend winding the valves ALL the way out tight.

[Andy W]

PS some manufacturers recommend winding the valves ALL the way out tight.

When I do that they always leak.

[Andy T]

Hi All just the last time I looked into changeing the valves on a 410a system for ball valves.I could not find any that had a high enough pressure rateing for 410a.this may have changed since 2 years ago.

[nike123]

I always taught that they are like rotalocks, that they are sealing at end points by mean of cone edges at shaft and valve body, and that in other positions is only o-ring that keep refrigerant from escape. Also, I saw in some manuals, that they indicate tightening torque for these valves end positions.

I think that problem is in valve making quality!

[Makeit go Right]

The system is leaking for sure, but who can say it is just the valve(s) that are leaking?

I'd say, repair the leak(s), one way or another, but also recover the remaining gas and test properly with nitrogen, over night. If/when the pressure test is sound, then move forward with charging the system.

R410a being a blend, you should put a new charge in the system, not simply top up.

[And, if it were a site in the UK, we'd tell the customer that the repair has to include a return visit in a month's time to recheck the system, to confirm that the repairs have held and no further leaks exist on the system. Then it's a done job.]

[paul_h]

I always taught that they are like rotalocks, that they are sealing at end points by mean of cone edges at shaft and valve body, and that in other positions is only o-ring that keep refrigerant from escape. Also, I saw in some manuals, that they indicate tightening torque for these valves end positions.

I think that problem is in valve making quality!

Nah, the end don't seal, and valve quality isn't it.
I've been dealing with fuji under 5 year warranties here for five years, plus fixing a lot of older over five year stuff too. It's fairly common to leak on the valve, some dont even start leaking until the unit is over 5 years old, ie perfect install, wound fully back etc, it just happens eventually.
Nearly every time I found a system short of refrig when the system is pretty old, it's the valves did leak as welds and flares are fine.
I was right all those times, but soldering in a new valve took a while to get the parts and wasn't the best way to spend my time.
This problem pre-dates cheaper units, bad installs, just certain brands etc. The only thing that stops the valve leaking is an O ring, fully backseating doesn't do anything (although that is preferred).
I've been to leaking valves from all different makes and models that leak so bad you get sprayed with refrigerant as you are winding it backwards. In fact the best valves are ones you dont seat entirely at all, ie they just have a removable circlip, so you can remove that entirely and remove the core and replace the worn o ring.
I learnt this trick when dealing with cars, some radiator/pump fittings leak, they are just clamp on, no proper fitting. All you do is replace the o ring and coat it in vegetable oil and it stops leaking. 3 way valves in a/cs are the same, the seal goes bad and deteriorates. If you are lucky and have an normal brand, remove circlip and replace o ring with a new oiled one.
If you are unlucky and have the pressed in false self sealing bullcrap that you can't repair, just wind in, oil, ind out and leaklock/threadtape the cap.
edit: as you have probably found, valves do leak even when backseated and capped. The same people that told you that they can't leak when fully wound back are they same people that told you that they can't leak extenally when the cap is on tight. Sounds like BS to me, brass on brass doesn't seal. I've spent heaps of hours pressurising and leak testing units to know there's no other place execpt that obviously leaking valve that could be the reason why the system is short of refrigerant.

[momo]

It would seem that leaking install a/c valves aren't the only ones. A/C Car valves caused my tester to howl when I started wondering why our office visit vehicle cesased to cool... Plastic caps with rubber ring and large schraeder... More R134a to warm the world (rain aside!)

[Jus1]

Reclaim gas. Boost the pressure with ofn for a pressure test. ( remembering pressure testing and leak testing pressures are different! ) So pressure test it first to see if it holds. Leave it in for a good few hours. Then reduce pressure for leak testing.

[trev]

i cud fix that if u fancyed givin me a full time job let me no trev

[airefresco]

That reminds me. The clients are back over on holiday next week, so I can go check it again. Hopefully, it´s not leaked this time.

[airefresco]

The clients came back over last night. So I went to site today to check on it. The system was still working, but it had lost a little bit of gas, nothing like what it did previously. Since last time I was there (6 months ago) I´ve bought a new electronic leak detector, so i went around with that. Nothing from the caps, so it looks they are OK now. However, I did get a reading from the schreider valve. Only when the detector was set to it´s highest, so it can´t be much of a leak. I replaced the schreider and put a bit of thread tape on the valve cap. Went around with the leak detector again and got nothing. So hopefully it´s going to be alright now, i´ll find out at Christmas when the clients will be out next.

If it leaks again, then I´m just going to rip the system out and put a new one in with new pipework. It´s cheaper than a bottle of Nitrogen and kilo of R410a. Sad, but true.

[sinewave]

If it leaks again, then I´m just going to rip the system out and put a new one in with new pipework. It´s cheaper than a bottle of Nitrogen and kilo of R410a. Sad, but true.

Must be cheap Tat you're installing back 2 back if that's the case!

[airefresco]

It was. We do Daikin now, but back in the day we were doing these units which to be fair, weren´t that bad. Obviously not in the same league as Daikin, ect. Another thing is we pay 10x the price of nitrogen here than what you do. No BOC here

[wilks]

The other option is to cut out the valves and flares then replace by brazing in a section of pipework - no future leaks....

thats what we allways do , hate making flares up anyway!!

[Harrison]

i see this problem all the time and it is usually on really nasty splits. if the unit cant justify cutting the valve out etc, evacuate, backfill to atm then use some sealant on the thread. i use a liquid one.
flaring is obviously a very difficult thing for some people because i see this sealant used by some split system bandits as subsitute for a decent flare as a matter of course!!! you would not believe what can hold pressure with a bit of that sealant.

[airefresco]

What sort of sealant?